From 28e9a7e1adfcd1f611d50c1603e544a2adcbd9b9 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 10:10:10 -0800
Subject: [PATCH 01/12] Renames ScreenViewRunner to ScreenViewUpdater

---
 .../overviewdetail/OverviewDetailContainer.kt |  6 ++--
 .../sample/poetryapp/PoemListScreen.kt        |  8 ++---
 ...ner.kt => HelloBackButtonLayoutUpdater.kt} |  8 ++---
 .../sample/poetry/StanzaListScreen.kt         |  8 ++---
 .../squareup/sample/poetry/StanzaScreen.kt    | 12 ++++----
 ...utRunner.kt => BoardsListLayoutUpdater.kt} | 10 +++----
 .../com/squareup/sample/dungeon/Component.kt  |  8 ++---
 ...meLayoutRunner.kt => GameLayoutUpdater.kt} |  8 ++---
 .../squareup/sample/dungeon/LoadingBinding.kt | 10 +++----
 ...t => ShakeableTimeMachineLayoutUpdater.kt} | 10 +++----
 .../shakeable/ShakeableTimeMachineWorkflow.kt |  2 +-
 .../helloworkflowfragment/HelloRendering.kt   |  4 +--
 .../sample/helloworkflow/HelloRendering.kt    |  4 +--
 .../sample/stubvisibility/OuterRendering.kt   |  4 +--
 .../authworkflow/AuthorizingViewFactory.kt    |  4 +--
 .../sample/authworkflow/LoginViewFactory.kt   |  4 +--
 .../authworkflow/SecondFactorViewFactory.kt   |  4 +--
 ...youtRunner.kt => GameOverLayoutUpdater.kt} | 10 +++----
 .../gameworkflow/GamePlayViewFactory.kt       |  4 +--
 .../sample/gameworkflow/NewGameViewFactory.kt |  4 +--
 .../gameworkflow/TicTacToeViewBindings.kt     |  2 +-
 .../squareup/sample/todo/TodoEditorScreen.kt  | 10 +++----
 .../squareup/sample/todo/TodoListsScreen.kt   |  2 +-
 workflow-ui/core-android/api/core-android.api |  6 ++--
 .../squareup/workflow1/ui/AndroidScreen.kt    |  6 ++--
 .../com/squareup/workflow1/ui/LayoutRunner.kt |  2 +-
 .../workflow1/ui/LayoutScreenViewFactory.kt   |  6 ++--
 .../workflow1/ui/ManualScreenViewFactory.kt   |  2 +-
 .../workflow1/ui/ScreenViewFactory.kt         |  2 +-
 ...reenViewRunner.kt => ScreenViewUpdater.kt} | 30 +++++++++----------
 .../ui/ViewBindingScreenViewFactory.kt        |  6 ++--
 31 files changed, 102 insertions(+), 104 deletions(-)
 rename samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/{HelloBackButtonLayoutRunner.kt => HelloBackButtonLayoutUpdater.kt} (80%)
 rename samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/{BoardsListLayoutRunner.kt => BoardsListLayoutUpdater.kt} (92%)
 rename samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/{GameLayoutRunner.kt => GameLayoutUpdater.kt} (91%)
 rename samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/{ShakeableTimeMachineLayoutRunner.kt => ShakeableTimeMachineLayoutUpdater.kt} (93%)
 rename samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/{GameOverLayoutRunner.kt => GameOverLayoutUpdater.kt} (92%)
 rename workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/{ScreenViewRunner.kt => ScreenViewUpdater.kt} (77%)

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
index 47b8b2c17c..fe0b099884 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
@@ -8,7 +8,7 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Detail
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Single
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -25,7 +25,7 @@ import com.squareup.workflow1.ui.container.withBackStackStateKeyPrefix
  * with [OverviewDetailScreen.overviewRendering] as the base of the stack.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class OverviewDetailContainer(view: View) : ScreenViewRunner<OverviewDetailScreen> {
+class OverviewDetailContainer(view: View) : ScreenViewUpdater<OverviewDetailScreen> {
 
   private val overviewStub: WorkflowViewStub? = view.findViewById(R.id.overview_stub)
   private val detailStub: WorkflowViewStub? = view.findViewById(R.id.detail_stub)
@@ -84,7 +84,7 @@ class OverviewDetailContainer(view: View) : ScreenViewRunner<OverviewDetailScree
     stub.show(combined, viewEnvironment + (OverviewDetailConfig to Single))
   }
 
-  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewRunner.bind(
+  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewUpdater.bind(
     layoutId = R.layout.overview_detail,
     constructor = ::OverviewDetailContainer
   ) {
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
index c6cfb50dac..e7bcf39ae3 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
@@ -12,7 +12,7 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overvie
 import com.squareup.sample.container.poetryapp.R
 import com.squareup.sample.poetry.model.Poem
 import com.squareup.workflow1.ui.AndroidScreen
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
@@ -22,14 +22,14 @@ data class PoemListScreen(
   val onPoemSelected: (Int) -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<PoemListScreen> {
-  override val viewFactory = ScreenViewRunner.bind(
+  override val viewFactory = ScreenViewUpdater.bind(
     R.layout.list,
-    ::PoemListLayoutRunner
+    ::PoemListLayoutUpdater
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class PoemListLayoutRunner(view: View) : ScreenViewRunner<PoemListScreen> {
+private class PoemListLayoutUpdater(view: View) : ScreenViewUpdater<PoemListScreen> {
   init {
     view.findViewById<Toolbar>(R.id.list_toolbar)
       .apply {
diff --git a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
similarity index 80%
rename from samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt
rename to samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
index 5250b429f2..679e0bcf0e 100644
--- a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt
+++ b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
@@ -4,7 +4,7 @@ import android.view.View
 import android.widget.TextView
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -15,13 +15,13 @@ data class HelloBackButtonScreen(
   val onClick: () -> Unit,
   val onBackPressed: (() -> Unit)?
 ) : AndroidScreen<HelloBackButtonScreen> {
-  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> = ScreenViewRunner.bind(
-    R.layout.hello_back_button_layout, ::HelloBackButtonLayoutRunner
+  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> = ScreenViewUpdater.bind(
+    R.layout.hello_back_button_layout, ::HelloBackButtonLayoutUpdater
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class HelloBackButtonLayoutRunner(view: View) : ScreenViewRunner<HelloBackButtonScreen> {
+private class HelloBackButtonLayoutUpdater(view: View) : ScreenViewUpdater<HelloBackButtonScreen> {
   private val messageView: TextView = view.findViewById(R.id.hello_message)
 
   override fun showRendering(
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
index ec5ebe70c6..0aaa566f71 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
@@ -12,7 +12,7 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overvie
 import com.squareup.sample.container.poetry.R
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -28,14 +28,14 @@ data class StanzaListScreen(
   val onExit: () -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<StanzaListScreen> {
-  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewRunner.bind(
+  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewUpdater.bind(
     R.layout.list,
-    ::StanzaListLayoutRunner
+    ::StanzaListLayoutUpdater
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class StanzaListLayoutRunner(view: View) : ScreenViewRunner<StanzaListScreen> {
+private class StanzaListLayoutUpdater(view: View) : ScreenViewUpdater<StanzaListScreen> {
   private val toolbar = view.findViewById<Toolbar>(R.id.list_toolbar)
   private val recyclerView = view.findViewById<RecyclerView>(R.id.list_body)
     .apply { layoutManager = LinearLayoutManager(context) }
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
index 7f3bdf8a57..6ea53afde8 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
@@ -14,7 +14,7 @@ import com.squareup.sample.container.poetry.R
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.Compatible
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -32,14 +32,14 @@ data class StanzaScreen(
 ) : AndroidScreen<StanzaScreen>, Compatible {
   override val compatibilityKey = "$title: $stanzaNumber"
 
-  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewRunner.bind(
+  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewUpdater.bind(
     R.layout.stanza_layout,
-    ::StanzaLayoutRunner
+    ::StanzaLayoutUpdater
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class StanzaLayoutRunner(private val view: View) : ScreenViewRunner<StanzaScreen> {
+private class StanzaLayoutUpdater(private val view: View) : ScreenViewUpdater<StanzaScreen> {
   private val tabSize = TypedValue
       .applyDimension(TypedValue.COMPLEX_UNIT_SP, 24f, view.resources.displayMetrics)
       .toInt()
@@ -114,8 +114,8 @@ private class StanzaLayoutRunner(private val view: View) : ScreenViewRunner<Stan
     setText(spans, SPANNABLE)
   }
 
-  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewRunner.bind(
+  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewUpdater.bind(
       R.layout.stanza_layout,
-      ::StanzaLayoutRunner
+      ::StanzaLayoutUpdater
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
similarity index 92%
rename from samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt
rename to samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
index 24db11abde..d0613b50c0 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
@@ -11,8 +11,8 @@ import com.squareup.cycler.toDataSource
 import com.squareup.sample.dungeon.DungeonAppWorkflow.DisplayBoardsListScreen
 import com.squareup.sample.dungeon.board.Board
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -24,7 +24,7 @@ import com.squareup.workflow1.ui.WorkflowViewStub
  * a `RecyclerView`.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class BoardsListLayoutRunner(rootView: View) : ScreenViewRunner<DisplayBoardsListScreen> {
+class BoardsListLayoutUpdater(rootView: View) : ScreenViewUpdater<DisplayBoardsListScreen> {
 
   /**
    * Used to associate a single [ViewEnvironment] and [DisplayBoardsListScreen.onBoardSelected]
@@ -48,7 +48,7 @@ class BoardsListLayoutRunner(rootView: View) : ScreenViewRunner<DisplayBoardsLis
           bind { _, item ->
             val card: CardView = view.findViewById(R.id.board_card)
             val boardNameView: TextView = view.findViewById(R.id.board_name)
-            // The board preview is actually rendered using the same ScreenViewRunner as the actual
+            // The board preview is actually rendered using the same ScreenViewUpdater as the actual
             // live game. It's easy to delegate to it by just putting a WorkflowViewStub in our
             // layout and giving it the Board.
             val boardPreviewView: WorkflowViewStub = view.findViewById(R.id.board_preview_stub)
@@ -102,6 +102,6 @@ class BoardsListLayoutRunner(rootView: View) : ScreenViewRunner<DisplayBoardsLis
   }
 
   companion object : ScreenViewFactory<DisplayBoardsListScreen> by bind(
-      R.layout.boards_list_layout, ::BoardsListLayoutRunner
+      R.layout.boards_list_layout, ::BoardsListLayoutUpdater
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/Component.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/Component.kt
index a3d5be2c97..f2df2f6157 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/Component.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/Component.kt
@@ -7,7 +7,7 @@ import android.os.Vibrator
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.sample.dungeon.DungeonAppWorkflow.State.LoadingBoardList
 import com.squareup.sample.dungeon.GameSessionWorkflow.State.Loading
-import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineLayoutRunner
+import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineLayoutUpdater
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.AlertContainer
@@ -24,11 +24,11 @@ class Component(context: AppCompatActivity) {
 
   @OptIn(WorkflowUiExperimentalApi::class)
   val viewRegistry = ViewRegistry(
-      ShakeableTimeMachineLayoutRunner,
+      ShakeableTimeMachineLayoutUpdater,
       LoadingBinding<LoadingBoardList>(R.string.loading_boards_list),
-      BoardsListLayoutRunner,
+      BoardsListLayoutUpdater,
       LoadingBinding<Loading>(R.string.loading_board),
-      GameLayoutRunner,
+      GameLayoutUpdater,
       BoardView,
       AlertContainer
   )
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
similarity index 91%
rename from samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt
rename to samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
index 7a096283f1..ca5f2d03f2 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
@@ -11,8 +11,8 @@ import com.squareup.sample.dungeon.Direction.RIGHT
 import com.squareup.sample.dungeon.Direction.UP
 import com.squareup.sample.dungeon.GameWorkflow.GameRendering
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -22,7 +22,7 @@ import com.squareup.workflow1.ui.WorkflowViewStub
  * the player.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class GameLayoutRunner(view: View) : ScreenViewRunner<GameRendering> {
+class GameLayoutUpdater(view: View) : ScreenViewUpdater<GameRendering> {
 
   private val boardView: WorkflowViewStub = view.findViewById(R.id.board_stub)
   private val moveLeft: View = view.findViewById(R.id.move_left)
@@ -67,6 +67,6 @@ class GameLayoutRunner(view: View) : ScreenViewRunner<GameRendering> {
   }
 
   companion object : ScreenViewFactory<GameRendering> by bind(
-      R.layout.game_layout, ::GameLayoutRunner
+      R.layout.game_layout, ::GameLayoutUpdater
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
index 019c97c2dc..4ec99d5991 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
@@ -7,8 +7,8 @@ import android.widget.TextView
 import androidx.annotation.StringRes
 import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
@@ -23,13 +23,13 @@ import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 inline fun <reified RenderingT : Screen> LoadingBinding(
   @StringRes loadingLabelRes: Int
 ): ScreenViewFactory<RenderingT> =
-  bind(R.layout.loading_layout) { view -> LoadingLayoutRunner(loadingLabelRes, view) }
+  bind(R.layout.loading_layout) { view -> LoadingLayoutUpdater(loadingLabelRes, view) }
 
 @PublishedApi
-internal class LoadingLayoutRunner<RenderingT : Screen>(
+internal class LoadingLayoutUpdater<RenderingT : Screen>(
   @StringRes private val labelRes: Int,
   view: View
-) : ScreenViewRunner<RenderingT> {
+) : ScreenViewUpdater<RenderingT> {
 
   init {
     view.findViewById<TextView>(R.id.loading_label)
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
similarity index 93%
rename from samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt
rename to samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
index c955a91404..77cf285d3b 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
@@ -8,8 +8,8 @@ import androidx.constraintlayout.widget.Group
 import androidx.transition.TransitionManager
 import com.squareup.sample.timemachine.shakeable.internal.GlassFrameLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -22,9 +22,9 @@ import kotlin.time.ExperimentalTime
  * [renderings][ShakeableTimeMachineScreen].
  */
 @OptIn(ExperimentalTime::class, WorkflowUiExperimentalApi::class)
-class ShakeableTimeMachineLayoutRunner(
+class ShakeableTimeMachineLayoutUpdater(
   private val view: View
-) : ScreenViewRunner<ShakeableTimeMachineScreen> {
+) : ScreenViewUpdater<ShakeableTimeMachineScreen> {
 
   private val glassView: GlassFrameLayout = view.findViewById(R.id.glass_view)
   private val childStub: WorkflowViewStub = view.findViewById(R.id.child_stub)
@@ -88,6 +88,6 @@ class ShakeableTimeMachineLayoutRunner(
   private fun Duration.toUiString(): String = toString()
 
   companion object : ScreenViewFactory<ShakeableTimeMachineScreen> by bind(
-      R.layout.shakeable_time_machine_layout, ::ShakeableTimeMachineLayoutRunner
+      R.layout.shakeable_time_machine_layout, ::ShakeableTimeMachineLayoutUpdater
   )
 }
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
index 0a3fea30fe..988a39a9b0 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
@@ -18,7 +18,7 @@ import kotlin.time.Duration
 import kotlin.time.ExperimentalTime
 
 /**
- * A wrapper around a [TimeMachineWorkflow] that uses [ShakeableTimeMachineLayoutRunner] to render
+ * A wrapper around a [TimeMachineWorkflow] that uses [ShakeableTimeMachineLayoutUpdater] to render
  * the [delegate workflow][TimeMachineWorkflow.delegateWorkflow]'s rendering, but wrap it in a
  * UI to scrub around the recorded timeline when the device is shaken.
  *
diff --git a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
index 3757079052..d852aca4d0 100644
--- a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
+++ b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
@@ -3,7 +3,7 @@ package com.squareup.sample.helloworkflowfragment
 import com.squareup.sample.helloworkflowfragment.databinding.HelloGoodbyeLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
@@ -12,7 +12,7 @@ data class HelloRendering(
   val onClick: () -> Unit
 ) : AndroidScreen<HelloRendering> {
   override val viewFactory: ScreenViewFactory<HelloRendering> =
-    ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
+    ScreenViewUpdater.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
       helloMessage.text = "${r.message} Fragment"
       helloMessage.setOnClickListener { r.onClick() }
     }
diff --git a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
index ee34b15391..ed32e30053 100644
--- a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
+++ b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
@@ -3,7 +3,7 @@ package com.squareup.sample.helloworkflow
 import com.squareup.sample.helloworkflow.databinding.HelloGoodbyeLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
@@ -12,7 +12,7 @@ data class HelloRendering(
   val onClick: () -> Unit
 ) : AndroidScreen<HelloRendering> {
   override val viewFactory: ScreenViewFactory<HelloRendering> =
-    ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
+    ScreenViewUpdater.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
       helloMessage.text = r.message
       helloMessage.setOnClickListener { r.onClick() }
     }
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
index ac22b64f52..ab12418734 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
@@ -3,7 +3,7 @@ package com.squareup.sample.stubvisibility
 import com.squareup.sample.stubvisibility.databinding.StubVisibilityLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
@@ -12,7 +12,7 @@ data class OuterRendering(
   val bottom: ClickyTextRendering
 ) : AndroidScreen<OuterRendering> {
   override val viewFactory: ScreenViewFactory<OuterRendering> =
-    ScreenViewRunner.bind(StubVisibilityLayoutBinding::inflate) { rendering, env ->
+    ScreenViewUpdater.bind(StubVisibilityLayoutBinding::inflate) { rendering, env ->
       shouldBeFilledStub.show(rendering.top, env)
       shouldBeWrappedStub.show(rendering.bottom, env)
     }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
index a9f2411280..4094c47823 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
@@ -2,11 +2,11 @@ package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.AuthorizingLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val AuthorizingViewFactory: ScreenViewFactory<AuthorizingScreen> =
-  ScreenViewRunner.bind(AuthorizingLayoutBinding::inflate) { rendering, _ ->
+  ScreenViewUpdater.bind(AuthorizingLayoutBinding::inflate) { rendering, _ ->
     authorizingMessage.text = rendering.message
   }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
index b16254b150..f236542940 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
@@ -2,13 +2,13 @@ package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.LoginLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val LoginViewFactory: ScreenViewFactory<LoginScreen> =
-  ScreenViewRunner.bind(LoginLayoutBinding::inflate) { rendering, _ ->
+  ScreenViewUpdater.bind(LoginLayoutBinding::inflate) { rendering, _ ->
     loginErrorMessage.text = rendering.errorMessage
 
     loginButton.setOnClickListener {
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
index 411a8db473..e513065f41 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
@@ -2,13 +2,13 @@ package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.SecondFactorLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val SecondFactorViewFactory: ScreenViewFactory<SecondFactorScreen> =
-  ScreenViewRunner.bind(SecondFactorLayoutBinding::inflate) { rendering, _ ->
+  ScreenViewUpdater.bind(SecondFactorLayoutBinding::inflate) { rendering, _ ->
     root.backPressedHandler = { rendering.onCancel() }
     secondFactorToolbar.setNavigationOnClickListener { rendering.onCancel() }
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
similarity index 92%
rename from samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt
rename to samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
index 2a2bf057f1..d9fe7ec206 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
@@ -11,16 +11,16 @@ import com.squareup.sample.gameworkflow.SyncState.SAVING
 import com.squareup.sample.tictactoe.databinding.BoardBinding
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal class GameOverLayoutRunner(
+internal class GameOverLayoutUpdater(
   private val binding: GamePlayLayoutBinding
-) : ScreenViewRunner<GameOverScreen> {
+) : ScreenViewUpdater<GameOverScreen> {
 
   private val saveItem: MenuItem = binding.gamePlayToolbar.menu.add("")
       .apply {
@@ -103,6 +103,6 @@ internal class GameOverLayoutRunner(
 
   /** Note how easily we're sharing this layout with [GamePlayViewFactory]. */
   companion object : ScreenViewFactory<GameOverScreen> by bind(
-      GamePlayLayoutBinding::inflate, ::GameOverLayoutRunner
+      GamePlayLayoutBinding::inflate, ::GameOverLayoutUpdater
   )
 }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
index d1eace7626..025588fc37 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
@@ -4,13 +4,13 @@ import android.view.View
 import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val GamePlayViewFactory: ScreenViewFactory<GamePlayScreen> =
-  ScreenViewRunner.bind(GamePlayLayoutBinding::inflate) { rendering, _ ->
+  ScreenViewUpdater.bind(GamePlayLayoutBinding::inflate) { rendering, _ ->
     renderBanner(rendering.gameState, rendering.playerInfo)
     rendering.gameState.board.render(gamePlayBoard.root)
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
index 53a4341e72..8ab5a1cc97 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
@@ -2,13 +2,13 @@ package com.squareup.sample.gameworkflow
 
 import com.squareup.sample.tictactoe.databinding.NewGameLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val NewGameViewFactory: ScreenViewFactory<NewGameScreen> =
-  ScreenViewRunner.bind(NewGameLayoutBinding::inflate) { rendering, _ ->
+  ScreenViewUpdater.bind(NewGameLayoutBinding::inflate) { rendering, _ ->
     if (playerX.text.isBlank()) playerX.setText(rendering.defaultNameX)
     if (playerO.text.isBlank()) playerO.setText(rendering.defaultNameO)
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/TicTacToeViewBindings.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/TicTacToeViewBindings.kt
index 5835cc3d00..8c2408a8d4 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/TicTacToeViewBindings.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/TicTacToeViewBindings.kt
@@ -7,5 +7,5 @@ import com.squareup.workflow1.ui.ViewRegistry
 val TicTacToeViewFactories = ViewRegistry(
     NewGameViewFactory,
     GamePlayViewFactory,
-    GameOverLayoutRunner
+    GameOverLayoutUpdater
 )
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
index 72ef00d114..bd754bec29 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
@@ -7,8 +7,8 @@ import android.view.inputmethod.InputMethodManager
 import com.squareup.sample.todo.databinding.TodoEditorLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.ScreenViewRunner
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -25,13 +25,13 @@ data class TodoEditorScreen(
 ) : AndroidScreen<TodoEditorScreen>, Compatible {
 
   override val compatibilityKey = Compatible.keyFor(this, "${session.id}")
-  override val viewFactory = bind(TodoEditorLayoutBinding::inflate, ::Runner)
+  override val viewFactory = bind(TodoEditorLayoutBinding::inflate, ::Updater)
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class Runner(
+private class Updater(
   private val binding: TodoEditorLayoutBinding
-) : ScreenViewRunner<TodoEditorScreen> {
+) : ScreenViewUpdater<TodoEditorScreen> {
 
   private val itemListView = ItemListView.fromLinearLayout(binding.itemContainer)
 
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
index 573dfd40c9..5a2a8be7df 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
@@ -7,7 +7,7 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overvie
 import com.squareup.sample.todo.databinding.TodoListsLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
diff --git a/workflow-ui/core-android/api/core-android.api b/workflow-ui/core-android/api/core-android.api
index 456cd95b6d..6311ec4e9d 100644
--- a/workflow-ui/core-android/api/core-android.api
+++ b/workflow-ui/core-android/api/core-android.api
@@ -100,12 +100,12 @@ public final class com/squareup/workflow1/ui/ScreenViewFactoryKt {
 	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lcom/squareup/workflow1/ui/ViewStarter;ILjava/lang/Object;)Landroid/view/View;
 }
 
-public abstract interface class com/squareup/workflow1/ui/ScreenViewRunner {
-	public static final field Companion Lcom/squareup/workflow1/ui/ScreenViewRunner$Companion;
+public abstract interface class com/squareup/workflow1/ui/ScreenViewUpdater {
+	public static final field Companion Lcom/squareup/workflow1/ui/ScreenViewUpdater$Companion;
 	public abstract fun showRendering (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
 }
 
-public final class com/squareup/workflow1/ui/ScreenViewRunner$Companion {
+public final class com/squareup/workflow1/ui/ScreenViewUpdater$Companion {
 }
 
 public final class com/squareup/workflow1/ui/SnapshotParcelsKt {
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
index 2d99280ee4..ad6a1c4f44 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
@@ -5,8 +5,8 @@ package com.squareup.workflow1.ui
  * via an appropriate [ScreenViewFactory] implementation.
  *
  * You will rarely, if ever, write a [ScreenViewFactory] yourself.  Instead
- * use [ScreenViewRunner.bind] to work with XML layout resources, or
- * [BuilderViewFactory] to create views from code.  See [ScreenViewRunner] for more
+ * use [ScreenViewUpdater.bind] to work with XML layout resources, or
+ * [BuilderViewFactory] to create views from code.  See [ScreenViewUpdater] for more
  * details.
  *
  *     @OptIn(WorkflowUiExperimentalApi::class)
@@ -15,7 +15,7 @@ package com.squareup.workflow1.ui
  *       val onClick: () -> Unit
  *     ) : AndroidScreen<HelloScreen> {
  *       override val viewFactory =
- *         ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { screen, _ ->
+ *         ScreenViewUpdater.bind(HelloGoodbyeLayoutBinding::inflate) { screen, _ ->
  *           helloMessage.text = screen.message
  *           helloMessage.setOnClickListener { screen.onClick() }
  *         }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
index 0300b09b43..e27c1db201 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
@@ -5,7 +5,7 @@ import androidx.annotation.LayoutRes
 import androidx.viewbinding.ViewBinding
 
 @Suppress("DEPRECATION")
-@Deprecated("Use ScreenViewRunner")
+@Deprecated("Use ScreenViewUpdater")
 @WorkflowUiExperimentalApi
 public fun interface LayoutRunner<RenderingT : Any> {
   public fun showRendering(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
index 49a117406b..d51e47a47b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -8,7 +8,7 @@ import kotlin.reflect.KClass
 
 /**
  * A [ScreenViewFactory] that ties a [layout resource][layoutId] to a
- * [ViewRunner factory][runnerConstructor] function. See [ScreenViewRunner] for
+ * [ViewRunner factory][updaterConstructor] function. See [ScreenViewUpdater] for
  * details.
  */
 @WorkflowUiExperimentalApi
@@ -16,7 +16,7 @@ import kotlin.reflect.KClass
 internal class LayoutScreenViewFactory<RenderingT : Screen>(
   override val type: KClass<RenderingT>,
   @LayoutRes private val layoutId: Int,
-  private val runnerConstructor: (View) -> ScreenViewRunner<RenderingT>
+  private val updaterConstructor: (View) -> ScreenViewUpdater<RenderingT>
 ) : ScreenViewFactory<RenderingT> {
   override fun buildView(
     initialRendering: RenderingT,
@@ -27,7 +27,7 @@ internal class LayoutScreenViewFactory<RenderingT : Screen>(
     return contextForNewView.viewBindingLayoutInflater(container)
       .inflate(layoutId, container, false)
       .also { view ->
-        val runner = runnerConstructor(view)
+        val runner = updaterConstructor(view)
         view.bindShowRendering(initialRendering, initialViewEnvironment) { rendering, environment ->
           runner.showRendering(rendering, environment)
         }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
index 97147b970e..3ad39f6cd8 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
@@ -7,7 +7,7 @@ import kotlin.reflect.KClass
 
 /**
  * A [ScreenViewFactory] that creates [View]s that need to be generated from code.
- * (Use [ScreenViewRunner] to work with XML layout resources.)
+ * (Use [ScreenViewUpdater] to work with XML layout resources.)
  *
  *    data class MyScreen(): AndroidScreen<MyView> {
  *      val viewFactory = ManualScreenViewFactory(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index a674dfbbf6..e019611858 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -15,7 +15,7 @@ import com.squareup.workflow1.ui.container.EnvironmentScreenViewFactory
  *
  * Two concrete [ScreenViewFactory] implementations are provided:
  *
- *  - The various [bind][ScreenViewRunner.bind] methods on [ScreenViewRunner] allow easy use of
+ *  - The various [bind][ScreenViewUpdater.bind] methods on [ScreenViewUpdater] allow easy use of
  *    Android XML layout resources and [AndroidX ViewBinding][androidx.viewbinding.ViewBinding].
  *
  *  - [ManualScreenViewFactory] allows views to be built from code.
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
similarity index 77%
rename from workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
index 52e51238fa..54a124c931 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
@@ -11,15 +11,13 @@ import androidx.viewbinding.ViewBinding
 public typealias ViewBindingInflater<BindingT> = (LayoutInflater, ViewGroup?, Boolean) -> BindingT
 
 /**
- * A delegate that implements a [showRendering] method to be called when a workflow
- * rendering of type [RenderingT] : [Screen] is ready to be displayed in a view created
- * by a [ScreenViewFactory].
+ * Function that updates the UI built by a  [ScreenViewFactory].
  *
  * If you're using [AndroidX ViewBinding][ViewBinding] you likely won't need to
- * implement this interface at all. For details, see the three overloads of [ScreenViewRunner.bind].
+ * implement this interface at all. For details, see the three overloads of [ScreenViewUpdater.bind].
  */
 @WorkflowUiExperimentalApi
-public fun interface ScreenViewRunner<RenderingT : Screen> {
+public fun interface ScreenViewUpdater<RenderingT : Screen> {
   public fun showRendering(
     rendering: RenderingT,
     viewEnvironment: ViewEnvironment
@@ -31,33 +29,33 @@ public fun interface ScreenViewRunner<RenderingT : Screen> {
      * to show renderings of type [RenderingT] : [Screen], using [a lambda][showRendering].
      *
      *    val HelloViewFactory: ScreenViewFactory<HelloScreen> =
-     *      ScreenViewRunner.bind(HelloGoodbyeViewBinding::inflate) { rendering, viewEnvironment ->
+     *      ScreenViewUpdater.bind(HelloGoodbyeViewBinding::inflate) { rendering, viewEnvironment ->
      *        helloMessage.text = rendering.message
      *        helloMessage.setOnClickListener { rendering.onClick(Unit) }
      *      }
      *
      * If you need to initialize your view before [showRendering] is called,
-     * implement [ScreenViewRunner] and create a binding using the `bind` variant
-     * that accepts a `(ViewBinding) -> ScreenViewRunner` function, below.
+     * implement [ScreenViewUpdater] and create a binding using the `bind` variant
+     * that accepts a `(ViewBinding) -> ScreenViewUpdater` function, below.
      */
     public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
       noinline bindingInflater: ViewBindingInflater<BindingT>,
       crossinline showRendering: BindingT.(RenderingT, ViewEnvironment) -> Unit
     ): ScreenViewFactory<RenderingT> = bind(bindingInflater) { binding ->
-      ScreenViewRunner { rendering, viewEnvironment ->
+      ScreenViewUpdater { rendering, viewEnvironment ->
         binding.showRendering(rendering, viewEnvironment)
       }
     }
 
     /**
      * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
-     * to show renderings of type [RenderingT] : [Screen], using a [ScreenViewRunner]
+     * to show renderings of type [RenderingT] : [Screen], using a [ScreenViewUpdater]
      * created by [constructor]. Handy if you need to perform some set up before
      * [showRendering] is called.
      *
      *   class HelloScreenRunner(
      *     private val binding: HelloGoodbyeViewBinding
-     *   ) : ScreenViewRunner<HelloScreen> {
+     *   ) : ScreenViewUpdater<HelloScreen> {
      *
      *     override fun showRendering(rendering: HelloScreen) {
      *       binding.messageView.text = rendering.message
@@ -74,29 +72,29 @@ public fun interface ScreenViewRunner<RenderingT : Screen> {
      */
     public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
       noinline bindingInflater: ViewBindingInflater<BindingT>,
-      noinline constructor: (BindingT) -> ScreenViewRunner<RenderingT>
+      noinline constructor: (BindingT) -> ScreenViewUpdater<RenderingT>
     ): ScreenViewFactory<RenderingT> =
       ViewBindingScreenViewFactory(RenderingT::class, bindingInflater, constructor)
 
     /**
      * Creates a [ScreenViewFactory] that inflates [layoutId] to show renderings of
-     * type [RenderingT]  : [Screen], using a [ScreenViewRunner] created by [constructor].
+     * type [RenderingT]  : [Screen], using a [ScreenViewUpdater] created by [constructor].
      * Avoids any use of [AndroidX ViewBinding][ViewBinding].
      */
     public inline fun <reified RenderingT : Screen> bind(
       @LayoutRes layoutId: Int,
-      noinline constructor: (View) -> ScreenViewRunner<RenderingT>
+      noinline constructor: (View) -> ScreenViewUpdater<RenderingT>
     ): ScreenViewFactory<RenderingT> =
       LayoutScreenViewFactory(RenderingT::class, layoutId, constructor)
 
     /**
      * Creates a [ScreenViewFactory] that inflates [layoutId] to "show" renderings of type [RenderingT],
-     * with a no-op [ScreenViewRunner]. Handy for showing static views, e.g. when prototyping.
+     * with a no-op [ScreenViewUpdater]. Handy for showing static views, e.g. when prototyping.
      */
     @Suppress("unused")
     public inline fun <reified RenderingT : Screen> bindNoRunner(
       @LayoutRes layoutId: Int
-    ): ScreenViewFactory<RenderingT> = bind(layoutId) { ScreenViewRunner { _, _ -> } }
+    ): ScreenViewFactory<RenderingT> = bind(layoutId) { ScreenViewUpdater { _, _ -> } }
   }
 }
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
index ab8d0b072a..f179d301ce 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -11,7 +11,7 @@ import kotlin.reflect.KClass
 internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, RenderingT : Screen>(
   override val type: KClass<RenderingT>,
   private val bindingInflater: ViewBindingInflater<BindingT>,
-  private val runnerConstructor: (BindingT) -> ScreenViewRunner<RenderingT>
+  private val updaterConstructor: (BindingT) -> ScreenViewUpdater<RenderingT>
 ) : ScreenViewFactory<RenderingT> {
   override fun buildView(
     initialRendering: RenderingT,
@@ -21,12 +21,12 @@ internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, RenderingT :
   ): View =
     bindingInflater(contextForNewView.viewBindingLayoutInflater(container), container, false)
       .also { binding ->
-        val runner = runnerConstructor(binding)
+        val updater = updaterConstructor(binding)
         binding.root.bindShowRendering(
           initialRendering,
           initialViewEnvironment
         ) { rendering, environment ->
-          runner.showRendering(rendering, environment)
+          updater.showRendering(rendering, environment)
         }
       }
       .root

From e2ddcb1357c600837463eea9bc33d584a4795938 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Thu, 6 Jan 2022 12:35:48 -0800
Subject: [PATCH 02/12] wip: Here is the ScreenView interface, how to use it?

---
 .../squareup/workflow1/ui/BaseScreenView.kt   |  29 +++++
 .../ui/DecorativeScreenViewFactory.kt         | 112 ------------------
 .../workflow1/ui/DecorativeViewFactory.kt     | 105 +++++++++++++++-
 .../workflow1/ui/LayoutScreenViewFactory.kt   |  29 ++---
 .../com/squareup/workflow1/ui/ScreenView.kt   |  75 ++++++++++++
 .../workflow1/ui/ScreenViewFactory.kt         |  35 ++----
 .../ui/ViewBindingScreenViewFactory.kt        |  34 +++---
 7 files changed, 249 insertions(+), 170 deletions(-)
 create mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt
 create mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt

diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt
new file mode 100644
index 0000000000..5895a852c4
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt
@@ -0,0 +1,29 @@
+package com.squareup.workflow1.ui
+
+import android.view.View
+
+@WorkflowUiExperimentalApi
+internal class BaseScreenView<ScreenT: Screen>(
+  private val initialRendering: ScreenT,
+  private val initialViewEnvironment: ViewEnvironment,
+  override val androidView: View,
+  private val runner: ScreenViewRunner<ScreenT>
+) : ScreenView<ScreenT> {
+  lateinit var currentRendering: ScreenT
+  lateinit var currentEnvironment: ViewEnvironment
+
+  override val rendering: ScreenT
+    get() = currentRendering
+  override val environment: ViewEnvironment
+    get() = currentEnvironment
+
+  override fun start() {
+    update(initialRendering, initialViewEnvironment)
+  }
+
+  override fun update(rendering: ScreenT, environment: ViewEnvironment) {
+    currentRendering = rendering
+    currentEnvironment = environment
+    runner.showRendering(rendering, environment)
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
index bc730bd23d..fe11de5c04 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
@@ -5,118 +5,6 @@ import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
-/**
- * A [ScreenViewFactory] for [OuterT] that delegates view construction responsibilities
- * to the factory registered for [InnerT]. Makes it convenient for [OuterT] to wrap
- * instances of [InnerT] to add information or behavior, without requiring wasteful wrapping
- * in the view system.
- *
- * One general note: when creating a wrapper rendering, you're very likely to want it
- * to implement [Compatible], to ensure that checks made to update or replace a view
- * are based on the wrapped item. Each wrapper example below illustrates this.
- *
- * ## Examples
- *
- * To make one rendering type an "alias" for another -- that is, to use the same [ScreenViewFactory]
- * to display it -- provide nothing but a single-arg mapping function:
- *
- *    class OriginalRendering(val data: String) : AndroidScreen<OriginalRendering> {
- *      ...
- *    }
- *    class AliasRendering(val similarData: String)
- *
- *    object DecorativeScreenViewFactory : ScreenViewFactory<AliasRendering>
- *    by DecorativeScreenViewFactory(
- *      type = AliasRendering::class, map = { alias ->
- *        OriginalRendering(alias.similarData)
- *      }
- *    )
- *
- * To make a wrapper that adds information to the [ViewEnvironment]:
- *
- *    class NeutronFlowPolarity(val reversed: Boolean) : Screen {
- *      companion object : ViewEnvironmentKey<NeutronFlowPolarity>(
- *        NeutronFlowPolarity::class
- *      ) {
- *        override val default: NeutronFlowPolarity =
- *          NeutronFlowPolarity(reversed = false)
- *      }
- *    }
- *
- *    class NeutronFlowPolarityOverride<W : Screen>(
- *      val wrapped: W,
- *      val polarity: NeutronFlowPolarity
- *    ) : Screen, Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object NeutronFlowPolarityViewFactory :
- *      ScreenViewFactory<NeutronFlowPolarityOverride<*>>
- *    by DecorativeScreenViewFactory(
- *        type = NeutronFlowPolarityOverride::class,
- *        map = { override, env ->
- *          Pair(override.wrapped, env + (NeutronFlowPolarity to override.polarity))
- *        }
- *    )
- *
- * To make a wrapper that customizes [View] initialization:
- *
- *    class WithTutorialTips<W : Screen>(val wrapped: W) : Screen, Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object WithTutorialTipsViewFactory : ScreenViewFactory<WithTutorialTips<*>>
- *    by DecorativeScreenViewFactory(
- *      type = WithTutorialTips::class,
- *      map = { withTips -> withTips.wrapped },
- *      viewStarter = { view, doStart ->
- *        TutorialTipRunner.run(this)
- *        doStart()
- *      }
- *    )
- *
- * To make a wrapper that adds pre- or post-processing to [View] updates:
- *
- *    class BackButtonScreen<W : Screen>(
- *       val wrapped: W,
- *       val override: Boolean = false,
- *       val onBackPressed: (() -> Unit)? = null
- *    ) : Screen, Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object BackButtonViewFactory : ScreenViewFactory<BackButtonScreen<*>>
- *    by DecorativeScreenViewFactory(
- *      type = BackButtonScreen::class,
- *      map = { outer -> outer.wrapped },
- *      doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
- *        if (!outerRendering.override) {
- *          // Place our handler before invoking innerShowRendering, so that
- *          // its later calls to view.backPressedHandler will take precedence
- *          // over ours.
- *          view.backPressedHandler = outerRendering.onBackPressed
- *        }
- *
- *        innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
- *
- *        if (outerRendering.override) {
- *          // Place our handler after invoking innerShowRendering, so that ours wins.
- *          view.backPressedHandler = outerRendering.onBackPressed
- *        }
- *      }
- *    )
- *
- * @param map called to convert instances of [OuterT] to [InnerT], and to
- * allow [ViewEnvironment] to be transformed.
- *
- * @param viewStarter An optional wrapper for the function invoked when [View.start]
- * is called, allowing for last second initialization of a newly built [View].
- * See [ViewStarter] for details.
- *
- * @param doShowRendering called to apply the [ViewShowRendering] function for
- * [InnerT], allowing pre- and post-processing. Default implementation simply
- * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
- */
 @WorkflowUiExperimentalApi
 public class DecorativeScreenViewFactory<OuterT : Screen, InnerT : Screen>(
   override val type: KClass<OuterT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
index a165c18155..aee909a446 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
@@ -5,8 +5,111 @@ import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
+/**
+ * A [ViewFactory] for [OuterT] that delegates view construction responsibilities
+ * to the factory registered for [InnerT]. Makes it convenient for [OuterT] to wrap
+ * instances of [InnerT] to add information or behavior, without requiring wasteful wrapping
+ * in the view system.
+ *
+ * One general note: when creating a wrapper rendering, you're very likely to want it
+ * to implement [Compatible], to ensure that checks made to update or replace a view
+ * are based on the wrapped item. Each example below illustrates this.
+ *
+ * ## Examples
+ *
+ * To make one rendering type an "alias" for another -- that is, to use the same [ViewFactory]
+ * to display it -- provide nothing but a single-arg mapping function:
+ *
+ *    class OriginalRendering(val data: String) : AndroidViewRendering<OriginalRendering> {...}
+ *    class AliasRendering(val similarData: String)
+ *
+ *    object DecorativeViewFactory : ViewFactory<AliasRendering>
+ *    by DecorativeViewFactory(
+ *      type = AliasRendering::class, map = { alias -> OriginalRendering(alias.similarData) }
+ *    )
+ *
+ * To make a decorator type that adds information to the [ViewEnvironment]:
+ *
+ *    class NeutronFlowPolarity(val reversed: Boolean) {
+ *      companion object : ViewEnvironmentKey<NeutronFlowPolarity>(NeutronFlowPolarity::class) {
+ *        override val default: NeutronFlowPolarity = NeutronFlowPolarity(reversed = false)
+ *      }
+ *    }
+ *
+ *    class NeutronFlowPolarityOverride<W>(
+ *      val wrapped: W,
+ *      val polarity: NeutronFlowPolarity
+ *    ) : Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object NeutronFlowPolarityViewFactory : ViewFactory<NeutronFlowPolarityOverride<*>>
+ *    by DecorativeViewFactory(
+ *        type = NeutronFlowPolarityOverride::class,
+ *        map = { override, env ->
+ *          Pair(override.wrapped, env + (NeutronFlowPolarity to override.polarity))
+ *        }
+ *    )
+ *
+ * To make a decorator type that customizes [View] initialization:
+ *
+ *    class WithTutorialTips<W>(val wrapped: W) : Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object WithTutorialTipsViewFactory : ViewFactory<WithTutorialTips<*>>
+ *    by DecorativeViewFactory(
+ *        type = WithTutorialTips::class,
+ *        map = { withTips -> withTips.wrapped },
+ *        viewStarter = { view, doStart ->
+ *          TutorialTipRunner.run(view)
+ *          doStart()
+ *        }
+ *    )
+ *
+ * To make a decorator type that adds pre- or post-processing to [View] updates:
+ *
+ *    class BackButtonScreen<W : Any>(
+ *       val wrapped: W,
+ *       val override: Boolean = false,
+ *       val onBackPressed: (() -> Unit)? = null
+ *    ) : Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object BackButtonViewFactory : ViewFactory<BackButtonScreen<*>>
+ *    by DecorativeViewFactory(
+ *        type = BackButtonScreen::class,
+ *        map = { outer -> outer.wrapped },
+ *        doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
+ *          if (!outerRendering.override) {
+ *            // Place our handler before invoking innerShowRendering, so that
+ *            // its later calls to view.backPressedHandler will take precedence
+ *            // over ours.
+ *            view.backPressedHandler = outerRendering.onBackPressed
+ *          }
+ *
+ *          innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
+ *
+ *          if (outerRendering.override) {
+ *            // Place our handler after invoking innerShowRendering, so that ours wins.
+ *            view.backPressedHandler = outerRendering.onBackPressed
+ *          }
+ *        })
+ *
+ * @param map called to convert instances of [OuterT] to [InnerT], and to
+ * allow [ViewEnvironment] to be transformed.
+ *
+ * @param viewStarter An optional wrapper for the function invoked when [View.start]
+ * is called, allowing for last second initialization of a newly built [View].
+ * See [ViewStarter] for details.
+ *
+ * @param doShowRendering called to apply the [ViewShowRendering] function for
+ * [InnerT], allowing pre- and post-processing. Default implementation simply
+ * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
+ */
 @Suppress("DEPRECATION")
-@Deprecated("Use DecorativeScreenViewFactory")
+@Deprecated("Use ManualScreenViewFactory")
 @WorkflowUiExperimentalApi
 public class DecorativeViewFactory<OuterT : Any, InnerT : Any>(
   override val type: KClass<OuterT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
index d51e47a47b..3c48b110c6 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -13,24 +13,25 @@ import kotlin.reflect.KClass
  */
 @WorkflowUiExperimentalApi
 @PublishedApi
-internal class LayoutScreenViewFactory<RenderingT : Screen>(
-  override val type: KClass<RenderingT>,
+internal class LayoutScreenViewFactory<ScreenT : Screen>(
+  override val type: KClass<ScreenT>,
   @LayoutRes private val layoutId: Int,
-  private val updaterConstructor: (View) -> ScreenViewUpdater<RenderingT>
-) : ScreenViewFactory<RenderingT> {
+  private val updaterConstructor: (View) -> ScreenViewUpdater<ScreenT>
+) : ScreenViewFactory<ScreenT> {
   override fun buildView(
-    initialRendering: RenderingT,
+    initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ): View {
-    return contextForNewView.viewBindingLayoutInflater(container)
-      .inflate(layoutId, container, false)
-      .also { view ->
-        val runner = updaterConstructor(view)
-        view.bindShowRendering(initialRendering, initialViewEnvironment) { rendering, environment ->
-          runner.showRendering(rendering, environment)
-        }
-      }
+  ): ScreenView<ScreenT> {
+    val view =
+      contextForNewView.viewBindingLayoutInflater(container).inflate(layoutId, container, false)
+
+    return BaseScreenView(
+      initialRendering = initialRendering,
+      initialViewEnvironment = initialViewEnvironment,
+      androidView = view,
+      runner = updaterConstructor(view)
+    )
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
new file mode 100644
index 0000000000..f54a0ca6f4
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
@@ -0,0 +1,75 @@
+package com.squareup.workflow1.ui
+
+import android.view.View
+
+@WorkflowUiExperimentalApi
+public interface ScreenView<ScreenT : Screen> {
+  public val rendering: ScreenT
+  public val environment: ViewEnvironment
+  public val androidView: View
+
+  public fun start()
+
+  public fun update(
+    rendering: ScreenT,
+    environment: ViewEnvironment
+  )
+
+  @WorkflowUiExperimentalApi
+  public interface Starter<ScreenT : Screen> {
+    /** Called from [start]. [doStart] must be invoked. */
+    public fun startView(
+      view: ScreenView<ScreenT>,
+      doStart: () -> Unit
+    )
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenView<ScreenT>.withStarter(
+  viewStarter: ScreenView.Starter<ScreenT>
+): ScreenView<ScreenT> {
+  return object : ScreenView<ScreenT> by this {
+    override fun start() {
+      viewStarter.startView(this@withStarter, this@withStarter::start)
+    }
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen, ScreenU : Screen> ScreenView<ScreenT>.mapRenderings(
+  transform: (ScreenU) -> ScreenT
+): ScreenView<ScreenU> {
+  return object: ScreenView<ScreenU> {
+    lateinit var unmapped: ScreenU
+
+    override val rendering: ScreenU
+      get() = unmapped
+
+    override val environment: ViewEnvironment
+      get() = this@mapRenderings.environment
+
+    override val androidView: View
+      get() = this@mapRenderings.androidView
+
+    override fun start() {
+      this@mapRenderings.start()
+    }
+
+    override fun update(rendering: ScreenU, environment: ViewEnvironment) {
+      unmapped = rendering
+      this@mapRenderings.update(transform(rendering), environment)
+    }
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenView<ScreenT>.mapEnvironment(
+  updater: (ViewEnvironment) -> ViewEnvironment
+): ScreenView<ScreenT>{
+  return object: ScreenView<ScreenT> by this {
+    override fun update(rendering: ScreenT, environment: ViewEnvironment) {
+      this@mapEnvironment.update(rendering, updater(environment))
+    }
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index e019611858..7abe494063 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -11,7 +11,7 @@ import com.squareup.workflow1.ui.container.EnvironmentScreen
 import com.squareup.workflow1.ui.container.EnvironmentScreenViewFactory
 
 /**
- * Factory for [View] instances that can show renderings of type [RenderingT] : [Screen].
+ * Factory for [View] instances that can show renderings of type [ScreenT] : [Screen].
  *
  * Two concrete [ScreenViewFactory] implementations are provided:
  *
@@ -25,17 +25,17 @@ import com.squareup.workflow1.ui.container.EnvironmentScreenViewFactory
  * avoid coupling your workflow directly to the Android runtime, see [ViewRegistry].
  */
 @WorkflowUiExperimentalApi
-public interface ScreenViewFactory<in RenderingT : Screen> : ViewRegistry.Entry<RenderingT> {
+public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<ScreenT> {
   /**
    * Returns a View ready to display [initialRendering] (and any succeeding values)
    * via [View.showRendering].
    */
   public fun buildView(
-    initialRendering: RenderingT,
+    initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup? = null
-  ): View
+  ): ScreenView<ScreenT>
 }
 
 /**
@@ -47,10 +47,6 @@ public interface ScreenViewFactory<in RenderingT : Screen> : ViewRegistry.Entry<
  * [View.showRendering] can be used to update it with new renderings that
  * are [compatible] with this [Screen]. [WorkflowViewStub] takes care of this chore itself.
  *
- * @param viewStarter An optional wrapper for the function invoked when [View.start]
- * is called, allowing for last second initialization of a newly built [View].
- * See [ViewStarter] for details.
- *
  * @throws IllegalArgumentException if no builder can be found for type [ScreenT]
  *
  * @throws IllegalStateException if the matching [ScreenViewFactory] fails to call
@@ -60,23 +56,11 @@ public interface ScreenViewFactory<in RenderingT : Screen> : ViewRegistry.Entry<
 public fun <ScreenT : Screen> ScreenT.buildView(
   viewEnvironment: ViewEnvironment,
   contextForNewView: Context,
-  container: ViewGroup? = null,
-  viewStarter: ViewStarter? = null,
-): View {
-  val viewFactory = viewEnvironment.getViewFactoryForRendering(this)
-
-  return viewFactory.buildView(this, viewEnvironment, contextForNewView, container).also { view ->
-    checkNotNull(view.workflowViewStateOrNull) {
-      "View.bindShowRendering should have been called for $view, typically by the " +
-        "ScreenViewFactory that created it."
-    }
-    viewStarter?.let { givenStarter ->
-      val doStart = view.starter
-      view.starter = { newView ->
-        givenStarter.startView(newView) { doStart.invoke(newView) }
-      }
-    }
-  }
+  container: ViewGroup? = null
+): ScreenView<ScreenT> {
+  return viewEnvironment.getViewFactoryForRendering(this).buildView(
+    this, viewEnvironment, contextForNewView, container
+  )
 }
 
 /**
@@ -90,6 +74,7 @@ public fun <ScreenT : Screen> ScreenT.buildView(
  * renderings can be mapped to other types.
  */
 @WorkflowUiExperimentalApi
+@Deprecated("Use WorkflowView.Starter")
 public fun interface ViewStarter {
   /** Called from [View.start]. [doStart] must be invoked. */
   public fun startView(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
index f179d301ce..17674b02d5 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -1,33 +1,31 @@
 package com.squareup.workflow1.ui
 
 import android.content.Context
-import android.view.View
 import android.view.ViewGroup
 import androidx.viewbinding.ViewBinding
 import kotlin.reflect.KClass
 
 @WorkflowUiExperimentalApi
 @PublishedApi
-internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, RenderingT : Screen>(
-  override val type: KClass<RenderingT>,
+internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, ScreenT : Screen>(
+  override val type: KClass<ScreenT>,
   private val bindingInflater: ViewBindingInflater<BindingT>,
-  private val updaterConstructor: (BindingT) -> ScreenViewUpdater<RenderingT>
-) : ScreenViewFactory<RenderingT> {
+  private val updaterConstructor: (BindingT) -> ScreenViewUpdater<ScreenT>
+) : ScreenViewFactory<ScreenT> {
   override fun buildView(
-    initialRendering: RenderingT,
+    initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ): View =
-    bindingInflater(contextForNewView.viewBindingLayoutInflater(container), container, false)
-      .also { binding ->
-        val updater = updaterConstructor(binding)
-        binding.root.bindShowRendering(
-          initialRendering,
-          initialViewEnvironment
-        ) { rendering, environment ->
-          updater.showRendering(rendering, environment)
-        }
-      }
-      .root
+  ): ScreenView<ScreenT> {
+    val binding = bindingInflater(
+      contextForNewView.viewBindingLayoutInflater(container), container, false
+    )
+    return BaseScreenView(
+      initialRendering,
+      initialViewEnvironment,
+      binding.root,
+      runner = updaterConstructor(binding)
+    )
+  }
 }

From c3ba36b5a4aca07d59b78471e8faba2d30f51108 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Thu, 6 Jan 2022 13:01:42 -0800
Subject: [PATCH 03/12] wip: playing with stub

---
 .../com/squareup/workflow1/ui/ScreenView.kt   |  7 ++-
 .../squareup/workflow1/ui/WorkflowViewStub.kt | 44 ++++++++++---------
 2 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
index f54a0ca6f4..f215b46a43 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
@@ -16,7 +16,7 @@ public interface ScreenView<ScreenT : Screen> {
   )
 
   @WorkflowUiExperimentalApi
-  public interface Starter<ScreenT : Screen> {
+  public fun interface Starter<ScreenT : Screen> {
     /** Called from [start]. [doStart] must be invoked. */
     public fun startView(
       view: ScreenView<ScreenT>,
@@ -25,6 +25,11 @@ public interface ScreenView<ScreenT : Screen> {
   }
 }
 
+@WorkflowUiExperimentalApi
+public fun ScreenView<*>.canShowRendering(screen: Screen): Boolean {
+  return compatible(rendering, screen)
+}
+
 @WorkflowUiExperimentalApi
 public fun <ScreenT : Screen> ScreenView<ScreenT>.withStarter(
   viewStarter: ScreenView.Starter<ScreenT>
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
index 46557974a0..779dfa013a 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
@@ -69,6 +69,8 @@ public class WorkflowViewStub @JvmOverloads constructor(
   defStyle: Int = 0,
   defStyleRes: Int = 0
 ) : View(context, attributeSet, defStyle, defStyleRes) {
+  private lateinit var showing: ScreenView<Screen>
+
   /**
    * On-demand access to the view created by the last call to [update],
    * or this [WorkflowViewStub] instance if none has yet been made.
@@ -207,11 +209,10 @@ public class WorkflowViewStub @JvmOverloads constructor(
     rendering: Screen,
     viewEnvironment: ViewEnvironment
   ): View {
-    actual.takeIf { it.canShowRendering(rendering) }
-      ?.let {
-        it.showRendering(rendering, viewEnvironment)
-        return it
-      }
+    if (this != actual && showing.canShowRendering(rendering)) {
+      showing.update(rendering, viewEnvironment)
+      return showing.androidView
+    }
 
     val parent = actual.parent as? ViewGroup
       ?: throw IllegalStateException("WorkflowViewStub must have a non-null ViewGroup parent")
@@ -230,25 +231,26 @@ public class WorkflowViewStub @JvmOverloads constructor(
       WorkflowLifecycleOwner.get(actual)?.destroyOnDetach()
     }
 
-    return rendering.buildView(
+    val newWorkflowView = rendering.buildView(
       viewEnvironment,
       parent.context,
-      parent,
-      viewStarter = { view, doStart ->
-        WorkflowLifecycleOwner.installOn(view)
-        doStart()
-      }
-    )
-      .also { newView ->
-        newView.start()
+      parent
+    ).withStarter { view, doStart ->
+      WorkflowLifecycleOwner.installOn(view.androidView)
+      doStart()
+    }
+    newWorkflowView.start()
 
-        if (inflatedId != NO_ID) newView.id = inflatedId
-        if (updatesVisibility) newView.visibility = visibility
-        background?.let { newView.background = it }
-        propagateSavedStateRegistryOwner(newView)
-        replaceOldViewInParent(parent, newView)
-        actual = newView
-      }
+    val newAndroidView = newWorkflowView.androidView
+
+    if (inflatedId != NO_ID) newAndroidView.id = inflatedId
+    if (updatesVisibility) newAndroidView.visibility = visibility
+    background?.let { newAndroidView.background = it }
+    propagateSavedStateRegistryOwner(newAndroidView)
+    replaceOldViewInParent(parent, newAndroidView)
+    actual = newAndroidView
+
+    return newWorkflowView.androidView
   }
 
   /**

From de2fc68488c4d6a3e057ca849f40decaf39e83ba Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Thu, 6 Jan 2022 15:42:44 -0800
Subject: [PATCH 04/12] wip: Stub looks done. Some call sites of start() need
 attention. Also remember to delete DecorativeScreenViewFactory and port the
 tests for it.

---
 .../overviewdetail/OverviewDetailContainer.kt |   5 +-
 .../sample/dungeon/BoardsListLayoutUpdater.kt |   2 +-
 ...eScreenView.kt => BaseScreenViewHolder.kt} |  16 +-
 .../workflow1/ui/LayoutScreenViewFactory.kt   |   6 +-
 .../com/squareup/workflow1/ui/ScreenView.kt   |  80 ---------
 .../workflow1/ui/ScreenViewFactory.kt         |   4 +-
 .../squareup/workflow1/ui/ScreenViewHolder.kt |  91 ++++++++++
 .../ui/ViewBindingScreenViewFactory.kt        |   4 +-
 .../squareup/workflow1/ui/WorkflowLayout.kt   |  10 +-
 .../squareup/workflow1/ui/WorkflowViewStub.kt | 157 +++++++++---------
 .../ui/container/BackStackContainer.kt        |  17 +-
 .../ModalScreenOverlayDialogFactory.kt        |   4 +-
 .../java/com/squareup/workflow1/ui/Screen.kt  |   2 +-
 .../internal/test/WorkflowUiTestActivity.kt   |   5 +-
 14 files changed, 209 insertions(+), 194 deletions(-)
 rename workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/{BaseScreenView.kt => BaseScreenViewHolder.kt} (58%)
 delete mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
 create mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
index fe0b099884..7dd6d44a02 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
@@ -60,14 +60,14 @@ class OverviewDetailContainer(view: View) : ScreenViewUpdater<OverviewDetailScre
       overviewStub!!.show(rendering.overviewRendering, overviewViewEnvironment)
       rendering.detailRendering
         ?.let { detail ->
-          detailStub!!.actual.visibility = VISIBLE
+          detailStub!!.delegateHolder.view.visibility = VISIBLE
           detailStub.show(
             detail,
             viewEnvironment + (OverviewDetailConfig to Detail)
           )
         }
         ?: run {
-          detailStub!!.actual.visibility = INVISIBLE
+          detailStub!!.delegateHolder.view.visibility = INVISIBLE
         }
     }
   }
@@ -89,6 +89,5 @@ class OverviewDetailContainer(view: View) : ScreenViewUpdater<OverviewDetailScre
     constructor = ::OverviewDetailContainer
   ) {
     private const val OverviewBackStackKey = "overview"
-    private const val DetailBackStackKey = "detail"
   }
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
index d0613b50c0..e473856b3b 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
@@ -57,7 +57,7 @@ class BoardsListLayoutUpdater(rootView: View) : ScreenViewUpdater<DisplayBoardsL
             boardPreviewView.show(item.board, item.viewEnvironment)
 
             // Gratuitous, hacky, inline test of WorkflowViewStub features.
-            check(boardPreviewView.actual.visibility == INVISIBLE) {
+            check(boardPreviewView.delegateHolder.view.visibility == INVISIBLE) {
               "Expected swizzled board to be INVISIBLE"
             }
             boardPreviewView.visibility = VISIBLE
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
similarity index 58%
rename from workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
index 5895a852c4..962688dbc0 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenView.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
@@ -3,27 +3,27 @@ package com.squareup.workflow1.ui
 import android.view.View
 
 @WorkflowUiExperimentalApi
-internal class BaseScreenView<ScreenT: Screen>(
+internal class BaseScreenViewHolder<ScreenT: Screen>(
   private val initialRendering: ScreenT,
   private val initialViewEnvironment: ViewEnvironment,
-  override val androidView: View,
+  override val view: View,
   private val runner: ScreenViewRunner<ScreenT>
-) : ScreenView<ScreenT> {
+) : ScreenViewHolder<ScreenT> {
   lateinit var currentRendering: ScreenT
   lateinit var currentEnvironment: ViewEnvironment
 
-  override val rendering: ScreenT
+  override val screen: ScreenT
     get() = currentRendering
   override val environment: ViewEnvironment
     get() = currentEnvironment
 
   override fun start() {
-    update(initialRendering, initialViewEnvironment)
+    showScreen(initialRendering, initialViewEnvironment)
   }
 
-  override fun update(rendering: ScreenT, environment: ViewEnvironment) {
-    currentRendering = rendering
+  override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
+    currentRendering = screen
     currentEnvironment = environment
-    runner.showRendering(rendering, environment)
+    runner.showRendering(screen, environment)
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
index 3c48b110c6..eeb8818f2b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -23,14 +23,14 @@ internal class LayoutScreenViewFactory<ScreenT : Screen>(
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ): ScreenView<ScreenT> {
+  ): ScreenViewHolder<ScreenT> {
     val view =
       contextForNewView.viewBindingLayoutInflater(container).inflate(layoutId, container, false)
 
-    return BaseScreenView(
+    return BaseScreenViewHolder(
       initialRendering = initialRendering,
       initialViewEnvironment = initialViewEnvironment,
-      androidView = view,
+      view = view,
       runner = updaterConstructor(view)
     )
   }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
deleted file mode 100644
index f215b46a43..0000000000
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenView.kt
+++ /dev/null
@@ -1,80 +0,0 @@
-package com.squareup.workflow1.ui
-
-import android.view.View
-
-@WorkflowUiExperimentalApi
-public interface ScreenView<ScreenT : Screen> {
-  public val rendering: ScreenT
-  public val environment: ViewEnvironment
-  public val androidView: View
-
-  public fun start()
-
-  public fun update(
-    rendering: ScreenT,
-    environment: ViewEnvironment
-  )
-
-  @WorkflowUiExperimentalApi
-  public fun interface Starter<ScreenT : Screen> {
-    /** Called from [start]. [doStart] must be invoked. */
-    public fun startView(
-      view: ScreenView<ScreenT>,
-      doStart: () -> Unit
-    )
-  }
-}
-
-@WorkflowUiExperimentalApi
-public fun ScreenView<*>.canShowRendering(screen: Screen): Boolean {
-  return compatible(rendering, screen)
-}
-
-@WorkflowUiExperimentalApi
-public fun <ScreenT : Screen> ScreenView<ScreenT>.withStarter(
-  viewStarter: ScreenView.Starter<ScreenT>
-): ScreenView<ScreenT> {
-  return object : ScreenView<ScreenT> by this {
-    override fun start() {
-      viewStarter.startView(this@withStarter, this@withStarter::start)
-    }
-  }
-}
-
-@WorkflowUiExperimentalApi
-public fun <ScreenT : Screen, ScreenU : Screen> ScreenView<ScreenT>.mapRenderings(
-  transform: (ScreenU) -> ScreenT
-): ScreenView<ScreenU> {
-  return object: ScreenView<ScreenU> {
-    lateinit var unmapped: ScreenU
-
-    override val rendering: ScreenU
-      get() = unmapped
-
-    override val environment: ViewEnvironment
-      get() = this@mapRenderings.environment
-
-    override val androidView: View
-      get() = this@mapRenderings.androidView
-
-    override fun start() {
-      this@mapRenderings.start()
-    }
-
-    override fun update(rendering: ScreenU, environment: ViewEnvironment) {
-      unmapped = rendering
-      this@mapRenderings.update(transform(rendering), environment)
-    }
-  }
-}
-
-@WorkflowUiExperimentalApi
-public fun <ScreenT : Screen> ScreenView<ScreenT>.mapEnvironment(
-  updater: (ViewEnvironment) -> ViewEnvironment
-): ScreenView<ScreenT>{
-  return object: ScreenView<ScreenT> by this {
-    override fun update(rendering: ScreenT, environment: ViewEnvironment) {
-      this@mapEnvironment.update(rendering, updater(environment))
-    }
-  }
-}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index 7abe494063..9b49f8bdde 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -35,7 +35,7 @@ public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<Screen
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup? = null
-  ): ScreenView<ScreenT>
+  ): ScreenViewHolder<ScreenT>
 }
 
 /**
@@ -57,7 +57,7 @@ public fun <ScreenT : Screen> ScreenT.buildView(
   viewEnvironment: ViewEnvironment,
   contextForNewView: Context,
   container: ViewGroup? = null
-): ScreenView<ScreenT> {
+): ScreenViewHolder<ScreenT> {
   return viewEnvironment.getViewFactoryForRendering(this).buildView(
     this, viewEnvironment, contextForNewView, container
   )
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
new file mode 100644
index 0000000000..a2c8f30154
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -0,0 +1,91 @@
+package com.squareup.workflow1.ui
+
+import android.view.View
+
+/**
+ * Wraps an [Android view][view] with:
+ *
+ * - the current [Screen] [screen] it's displaying
+ * - the [environment] that [screen] was shown with
+ * - a [showScreen] method to refresh it
+ *
+ * Instances are created via [ScreenViewFactory.buildView]. [start] must be called
+ * exactly once before [showScreen], to initialize the new view. Use [withStarter] to
+ * customize what the [start] method does.
+ */
+@WorkflowUiExperimentalApi
+public interface ScreenViewHolder<ScreenT : Screen> {
+  public val screen: ScreenT
+  public val environment: ViewEnvironment
+  public val view: View
+
+  public fun start()
+
+  public fun showScreen(
+    screen: ScreenT,
+    environment: ViewEnvironment
+  )
+
+  @WorkflowUiExperimentalApi
+  public fun interface Starter<ScreenT : Screen> {
+    /** Called from [start]. [doStart] must be invoked. */
+    public fun startView(
+      viewHolder: ScreenViewHolder<ScreenT>,
+      doStart: () -> Unit
+    )
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun ScreenViewHolder<*>.canShowScreen(screen: Screen): Boolean {
+  return compatible(this.screen, screen)
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withStarter(
+  viewStarter: ScreenViewHolder.Starter<ScreenT>
+): ScreenViewHolder<ScreenT> {
+  return object : ScreenViewHolder<ScreenT> by this {
+    override fun start() {
+      viewStarter.startView(this@withStarter, this@withStarter::start)
+    }
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen, ScreenU : Screen> ScreenViewHolder<ScreenT>.mapRenderings(
+  transform: (ScreenU) -> ScreenT
+): ScreenViewHolder<ScreenU> {
+  return object: ScreenViewHolder<ScreenU> {
+    lateinit var unmapped: ScreenU
+
+    override val screen: ScreenU
+      get() = unmapped
+
+    override val environment: ViewEnvironment
+      get() = this@mapRenderings.environment
+
+    override val view: View
+      get() = this@mapRenderings.view
+
+    override fun start() {
+      this@mapRenderings.start()
+    }
+
+    override fun showScreen(screen: ScreenU, environment: ViewEnvironment) {
+      unmapped = screen
+      this@mapRenderings.showScreen(transform(screen), environment)
+    }
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.mapEnvironment(
+  updater: (ViewEnvironment) -> ViewEnvironment
+): ScreenViewHolder<ScreenT>{
+  return object: ScreenViewHolder<ScreenT> by this {
+    override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
+      this@mapEnvironment.showScreen(screen, updater(environment))
+    }
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
index 17674b02d5..8974af0d5d 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -17,11 +17,11 @@ internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, ScreenT : Sc
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ): ScreenView<ScreenT> {
+  ): ScreenViewHolder<ScreenT> {
     val binding = bindingInflater(
       contextForNewView.viewBindingLayoutInflater(container), container, false
     )
-    return BaseScreenView(
+    return BaseScreenViewHolder(
       initialRendering,
       initialViewEnvironment,
       binding.root,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
index 1cb6b2bcc7..05b5f5cf4e 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
@@ -39,7 +39,7 @@ public class WorkflowLayout(
     if (id == NO_ID) id = R.id.workflow_layout
   }
 
-  private val showing: WorkflowViewStub = WorkflowViewStub(context).also { rootStub ->
+  private val stub: WorkflowViewStub = WorkflowViewStub(context).also { rootStub ->
     rootStub.updatesVisibility = false
     addView(rootStub, ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT))
   }
@@ -103,17 +103,19 @@ public class WorkflowLayout(
   }
 
   private fun show(rootScreen: EnvironmentScreen<*>) {
-    showing.show(rootScreen.screen, rootScreen.viewEnvironment)
+    stub.show(rootScreen.screen, rootScreen.viewEnvironment)
     restoredChildState?.let { restoredState ->
       restoredChildState = null
-      showing.actual.restoreHierarchyState(restoredState)
+      stub.delegateHolder.view.restoreHierarchyState(restoredState)
     }
   }
 
   override fun onSaveInstanceState(): Parcelable {
     return SavedState(
       super.onSaveInstanceState()!!,
-      SparseArray<Parcelable>().also { array -> showing.actual.saveHierarchyState(array) }
+      SparseArray<Parcelable>().also { array ->
+        stub.delegateHolder.view.saveHierarchyState(array)
+      }
     )
   }
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
index 779dfa013a..35f8daf941 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
@@ -59,8 +59,8 @@ import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
  * Use [updatesVisibility] and [setBackground] for more control of how [update]
  * effects the visibility and backgrounds of created views.
  *
- * Use [replaceOldViewInParent] to customize replacing [actual] with a new view, e.g.
- * for animated transitions.
+ * Use [replaceOldViewInParent] to customize replacing the current view with a new one during
+ * [show], e.g. for animated transitions.
  */
 @WorkflowUiExperimentalApi
 public class WorkflowViewStub @JvmOverloads constructor(
@@ -69,19 +69,41 @@ public class WorkflowViewStub @JvmOverloads constructor(
   defStyle: Int = 0,
   defStyleRes: Int = 0
 ) : View(context, attributeSet, defStyle, defStyleRes) {
-  private lateinit var showing: ScreenView<Screen>
+  /** Returns null if [update] hasn't been called yet. */
+  private val delegateOrNull: View?
+    get() {
+      // can be null when called from the constructor.
+      @Suppress("UNNECESSARY_SAFE_CALL")
+      return delegateHolder?.view?.takeUnless { it === this }
+    }
 
-  /**
-   * On-demand access to the view created by the last call to [update],
-   * or this [WorkflowViewStub] instance if none has yet been made.
-   */
-  public var actual: View = this
+  public var delegateHolder: ScreenViewHolder<Screen> = object : ScreenViewHolder<Screen> {
+    override val screen: Screen = object : Screen {}
+    override val environment: ViewEnvironment = ViewEnvironment(mapOf())
+
+    override val view: View = this@WorkflowViewStub
+
+    override fun start() {
+      throw UnsupportedOperationException()
+    }
+
+    override fun showScreen(
+      screen: Screen,
+      environment: ViewEnvironment
+    ) {
+      throw UnsupportedOperationException()
+    }
+  }
     private set
 
+  @Deprecated("Use delegateHolder.view", ReplaceWith("delegateHolder.view"))
+  public val actual: View
+    get() = delegateHolder.view
+
   /**
-   * If true, the visibility of views created by [update] will be copied
-   * from that of [actual]. Bear in mind that the initial value of
-   * [actual] is this stub.
+   * If true, the visibility of new delegate views created by [update] will be copied
+   * from the current one. The first delegate created will copy the visibility of
+   * this stub.
    */
   public var updatesVisibility: Boolean = true
 
@@ -116,14 +138,15 @@ public class WorkflowViewStub @JvmOverloads constructor(
   }
 
   /**
-   * Function called from [update] to replace this stub, or the current [actual],
+   * Function called from [update] to replace this stub, or its current delegate,
    * with a new view. Can be updated to provide custom transition effects.
    *
    * Note that this method is responsible for copying the [layoutParams][getLayoutParams]
-   * from the stub to the new view. Also note that in a [WorkflowViewStub] that has never
-   * been updated, [actual] is the stub itself.
+   * from the stub to the new view.
    */
   public var replaceOldViewInParent: (ViewGroup, View) -> Unit = { parent, newView ->
+    val actual = delegateHolder.view
+
     val index = parent.indexOfChild(actual)
     parent.removeView(actual)
     actual.layoutParams
@@ -132,44 +155,32 @@ public class WorkflowViewStub @JvmOverloads constructor(
   }
 
   /**
-   * Sets the visibility of [actual]. If [updatesVisibility] is true, the visibility of
-   * new views created by [update] will copied from [actual]. (Bear in mind that the initial
-   * value of [actual] is this stub.)
+   * Sets the visibility of the delegate, or of this stub if [show] has not yet been called.
+   *
+   * @see updatesVisibility
    */
   override fun setVisibility(visibility: Int) {
     super.setVisibility(visibility)
-    // actual can be null when called from the constructor.
-    @Suppress("SENSELESS_COMPARISON")
-    if (actual != this && actual != null) {
-      actual.visibility = visibility
+    delegateOrNull?.takeUnless { it == this }?.let {
+      it.visibility = visibility
     }
   }
 
   /**
-   * Returns the visibility of [actual]. (Bear in mind that the initial value of
-   * [actual] is this stub.)
+   * Returns the visibility of the delegate, or of this stub if [show] has not yet been called.
    */
   override fun getVisibility(): Int {
-    // actual can be null when called from the constructor.
-    @Suppress("SENSELESS_NULL_IN_WHEN")
-    return when (actual) {
-      this, null -> super.getVisibility()
-      else -> actual.visibility
-    }
+    return delegateOrNull?.visibility ?: super.getVisibility()
   }
 
   /**
-   * Sets the background of this stub as usual, and also that of [actual]
-   * if the given [background] is not null. Any new views created by [update]
+   * Sets the background of this stub as usual, and also that of the delegate view,
+   * if the given [background] is not null. Any new delegates created by [update]
    * will be assigned this background, again if it is not null.
    */
   override fun setBackground(background: Drawable?) {
     super.setBackground(background)
-    // actual can be null when called from the constructor.
-    @Suppress("SENSELESS_COMPARISON")
-    if (actual != this && actual != null && background != null) {
-      actual.background = background
-    }
+    if (background != null) delegateOrNull?.background = background
   }
 
   @Deprecated("Use show()", ReplaceWith("show(rendering, viewEnvironment)"))
@@ -178,79 +189,73 @@ public class WorkflowViewStub @JvmOverloads constructor(
     viewEnvironment: ViewEnvironment
   ): View {
     @Suppress("DEPRECATION")
-    return show(asScreen(rendering), viewEnvironment)
+    show(asScreen(rendering), viewEnvironment)
+    return delegateHolder.view
   }
 
   /**
-   * Replaces this view with one that can display [rendering]. If the receiver
-   * has already been replaced, updates the replacement if it [canShowRendering].
-   * If the current replacement can't handle [rendering], a new view is put in its place.
+   * Replaces this view with a [delegate][delegateHolder] that can display [screen].
+   * If [show] has already been called previously, updates the current delegate if it
+   * [canShowScreen]. If the current delegate can't handle [screen], a new view
+   * is put in its place.
    *
-   * The [id][View.setId] of any view created by this method will be set to to [inflatedId],
+   * The [id][View.setId] of any delegate view created by this method will be set to to [inflatedId],
    * unless that value is [View.NO_ID].
    *
-   * The [background][setBackground] of any view created by this method will be copied
+   * The [background][setBackground] of any delegate view created by this method will be copied
    * from [getBackground], if that value is non-null.
    *
-   * If [updatesVisibility] is true, the [visibility][setVisibility] of any view created by
-   * this method will be copied from [actual]. (Bear in mind that the initial value of
-   * [actual] is this stub.)
-   *
-   * @return the view that showed [rendering]
+   * If [updatesVisibility] is true, the [visibility][setVisibility] of any delegate view created
+   * by this method will be copied from [getVisibility].
    *
-   * @throws IllegalArgumentException if no binding can be found for the type of [rendering]
+   * @return the view that showed [screen]
    *
-   * @throws IllegalStateException if the matching
-   * [ViewFactory][com.squareup.workflow1.ui.ViewFactory] fails to call
-   * [View.bindShowRendering][com.squareup.workflow1.ui.bindShowRendering]
-   * when constructing the view
+   * @throws IllegalArgumentException if no binding can be found for the type of [screen]
    */
   public fun show(
-    rendering: Screen,
+    screen: Screen,
     viewEnvironment: ViewEnvironment
-  ): View {
-    if (this != actual && showing.canShowRendering(rendering)) {
-      showing.update(rendering, viewEnvironment)
-      return showing.androidView
-    }
+  ) {
+    delegateHolder.takeIf { it.canShowScreen(screen) }
+      ?.let {
+        it.showScreen(screen, viewEnvironment)
+        return
+      }
 
-    val parent = actual.parent as? ViewGroup
+    val parent = delegateHolder.view.parent as? ViewGroup
       ?: throw IllegalStateException("WorkflowViewStub must have a non-null ViewGroup parent")
 
-    // If we have a delegate view (i.e. this !== actual), then the old delegate is going to
-    // eventually be detached by replaceOldViewInParent. When that happens, it's not just a regular
-    // detach, it's a navigation event that effectively says that view will never come back. Thus,
-    // we want its Lifecycle to move to permanently destroyed, even though the parent lifecycle is
-    // still probably alive.
+    // If we have a delegate view, then the old delegate is going to eventually be detached by
+    // replaceOldViewInParent. When that happens, it's not just a regular detach, it's a navigation
+    // event that effectively says that view will never come back. Thus, we want its Lifecycle to
+    // move to permanently destroyed, even though the parent lifecycle is still probably alive.
     //
-    // If actual === this, then this stub hasn't been initialized with a real delegate view yet. If
-    // we're a child of another container which set a WorkflowLifecycleOwner on this view, this
-    // get() call will return the WLO owned by that parent. We noop in that case since destroying
-    // that lifecycle is our parent's responsibility in that case, not ours.
-    if (actual !== this) {
-      WorkflowLifecycleOwner.get(actual)?.destroyOnDetach()
+    // If there isn't a delegate, we're a child of another container which set a
+    // WorkflowLifecycleOwner on this view, this get() call will return the WLO owned by that
+    // parent. We noop in that case since destroying that lifecycle is our parent's responsibility
+    // in that case, not ours.
+    delegateOrNull?.let {
+      WorkflowLifecycleOwner.get(it)?.destroyOnDetach()
     }
 
-    val newWorkflowView = rendering.buildView(
+    val newWorkflowView = screen.buildView(
       viewEnvironment,
       parent.context,
       parent
     ).withStarter { view, doStart ->
-      WorkflowLifecycleOwner.installOn(view.androidView)
+      WorkflowLifecycleOwner.installOn(view.view)
       doStart()
     }
     newWorkflowView.start()
 
-    val newAndroidView = newWorkflowView.androidView
+    val newAndroidView = newWorkflowView.view
 
     if (inflatedId != NO_ID) newAndroidView.id = inflatedId
     if (updatesVisibility) newAndroidView.visibility = visibility
     background?.let { newAndroidView.background = it }
     propagateSavedStateRegistryOwner(newAndroidView)
     replaceOldViewInParent(parent, newAndroidView)
-    actual = newAndroidView
-
-    return newWorkflowView.androidView
+    delegateHolder = newWorkflowView
   }
 
   /**
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
index be81a2590f..39e00d4bc9 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
@@ -27,7 +27,7 @@ import com.squareup.workflow1.ui.container.BackStackConfig.First
 import com.squareup.workflow1.ui.container.BackStackConfig.Other
 import com.squareup.workflow1.ui.container.ViewStateCache.SavedState
 import com.squareup.workflow1.ui.showRendering
-import com.squareup.workflow1.ui.start
+import com.squareup.workflow1.ui.withStarter
 
 /**
  * A container view that can display a stream of [BackStackScreen] instances.
@@ -98,18 +98,17 @@ public open class BackStackContainer @JvmOverloads constructor(
     val newView = named.top.buildView(
       viewEnvironment = environment,
       contextForNewView = this.context,
-      container = this,
-      viewStarter = { view, doStart ->
-        WorkflowLifecycleOwner.installOn(view)
-        doStart()
-      }
-    )
+      container = this
+    ).withStarter { view, doStart ->
+      WorkflowLifecycleOwner.installOn(view.view)
+      doStart()
+    }
     newView.start()
-    viewStateCache.update(named.backStack, oldViewMaybe, newView)
+    viewStateCache.update(named.backStack, oldViewMaybe, newView.view)
 
     val popped = currentRendering?.backStack?.any { compatible(it, named.top) } == true
 
-    performTransition(oldViewMaybe, newView, popped)
+    performTransition(oldViewMaybe, newView.view, popped)
     // Notify the view we're about to replace that it's going away.
     oldViewMaybe?.let(WorkflowLifecycleOwner::get)?.destroyOnDetach()
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
index 6cdc8045e2..d7bcfd07a5 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
@@ -15,9 +15,7 @@ import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 import com.squareup.workflow1.ui.buildView
-import com.squareup.workflow1.ui.environment
 import com.squareup.workflow1.ui.showRendering
-import com.squareup.workflow1.ui.start
 import java.lang.IllegalStateException
 import kotlin.reflect.KClass
 
@@ -68,7 +66,7 @@ public abstract class ModalScreenOverlayDialogFactory<O : ScreenOverlay<*>>(
       // If the content view has no backPressedHandler, add a no-op one to
       // ensure that the `onBackPressed` call below will not leak up to handlers
       // that should be blocked by this modal session.
-      if (backPressedHandler == null) backPressedHandler = { }
+      if (view.backPressedHandler == null) view.backPressedHandler = { }
     }
 
     return buildDialogWithContentView(contentView).also { dialog ->
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt
index 37b586e8aa..ffcac814cf 100644
--- a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt
@@ -1,7 +1,7 @@
 package com.squareup.workflow1.ui
 
 /**
- * Marker interface implemented by renderings that map to a UI system's 2d view class.
+ * Marker interface implemented by renderings that model a UI system's 2d box / view class.
  */
 @WorkflowUiExperimentalApi
 public interface Screen
diff --git a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
index 70676137ae..2a625206d8 100644
--- a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
+++ b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
@@ -45,7 +45,7 @@ public open class WorkflowUiTestActivity : AppCompatActivity() {
   /**
    * The [View] that was created to display the last rendering passed to [setRendering].
    */
-  public val rootRenderedView: View get() = rootStub.actual
+  public val rootRenderedView: View get() = rootStub.delegateHolder.view
 
   /**
    * Key-value store for custom values that should be retained across configuration changes.
@@ -104,7 +104,8 @@ public open class WorkflowUiTestActivity : AppCompatActivity() {
       wrapped = rendering,
       name = renderingCounter.toString()
     )
-    return rootStub.show(named, viewEnvironment)
+    rootStub.show(named, viewEnvironment)
+    return rootStub.delegateHolder.view
   }
 
   private class NonConfigurationData(

From 2ad84bb9936c99a3f6a3127330f757a09039d707 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 08:49:36 -0800
Subject: [PATCH 05/12] wip: time to burn down decorator

---
 .../panel/PanelOverlayDialogFactory.kt        |  6 +-
 .../workflow1/ui/modal/ModalViewContainer.kt  | 87 ++++++++++---------
 .../squareup/workflow1/ui/WorkflowViewStub.kt |  8 +-
 .../ModalScreenOverlayDialogFactory.kt        | 17 ++--
 .../ModalScreenOverlayOnBackPressed.kt        |  8 +-
 5 files changed, 64 insertions(+), 62 deletions(-)

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
index 6a697a7e20..f896eb47e4 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
@@ -17,10 +17,10 @@ import com.squareup.workflow1.ui.container.setBounds
 internal object PanelOverlayDialogFactory : ModalScreenOverlayDialogFactory<PanelOverlay<*>>(
   type = PanelOverlay::class
 ) {
-  override fun buildDialogWithContentView(contentView: View): Dialog {
-    val context = contentView.context
+  override fun buildDialogWithContent(content: View): Dialog {
+    val context = content.context
     return Dialog(context, R.style.PanelDialog).also { dialog ->
-      dialog.setContentView(contentView)
+      dialog.setContentView(content)
 
       // Welcome to Android. Nothing workflow-related here, this is just how one
       // finds the window background color for the theme. I sure hope it's better in Compose.
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
index e2b9e7986c..4e4076b0d1 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
@@ -12,18 +12,17 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.view.ViewGroup.LayoutParams.WRAP_CONTENT
 import androidx.annotation.IdRes
-import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.BuilderViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.backPressedHandler
 import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.buildView
 import com.squareup.workflow1.ui.modal.ModalViewContainer.Companion.binding
 import com.squareup.workflow1.ui.onBackPressedDispatcherOwnerOrNull
 import com.squareup.workflow1.ui.showRendering
-import com.squareup.workflow1.ui.start
 import kotlin.reflect.KClass
 
 /**
@@ -65,45 +64,47 @@ public open class ModalViewContainer @JvmOverloads constructor(
     initialModalRendering: Any,
     initialViewEnvironment: ViewEnvironment
   ): DialogRef<Any> {
-    val view = asScreen(initialModalRendering).buildView(
-            viewEnvironment = initialViewEnvironment,
-            contextForNewView = this.context,
-            container = this
-    )
-        .apply {
-          start()
-          // If the modal's root view has no backPressedHandler, add a no-op one to
-          // ensure that the `onBackPressed` call below will not leak up to handlers
-          // that should be blocked by this modal session.
-          if (backPressedHandler == null) backPressedHandler = { }
-        }
+    val view = asScreen(initialModalRendering)
+      .buildView(
+        viewEnvironment = initialViewEnvironment,
+        contextForNewView = this.context,
+        container = this
+      )
+      .let { holder ->
+        holder.start()
+        holder.view
+      }
+    // If the modal's root view has no backPressedHandler, add a no-op one to
+    // ensure that the `onBackPressed` call below will not leak up to handlers
+    // that should be blocked by this modal session.
+    if (view.backPressedHandler == null) view.backPressedHandler = { }
 
     return buildDialogForView(view)
-        .apply {
-          // Dialogs are modal windows and so they block events, including back button presses
-          // -- that's their job! But we *want* the Activity's onBackPressedDispatcher to fire
-          // when back is pressed, so long as it doesn't look past this modal window for handlers.
-          //
-          // Here, we handle the ACTION_UP portion of a KEYCODE_BACK key event, and below
-          // we make sure that the root view has a backPressedHandler that will consume the
-          // onBackPressed call if no child of the root modal view does.
+      .apply {
+        // Dialogs are modal windows and so they block events, including back button presses
+        // -- that's their job! But we *want* the Activity's onBackPressedDispatcher to fire
+        // when back is pressed, so long as it doesn't look past this modal window for handlers.
+        //
+        // Here, we handle the ACTION_UP portion of a KEYCODE_BACK key event, and below
+        // we make sure that the root view has a backPressedHandler that will consume the
+        // onBackPressed call if no child of the root modal view does.
 
-          setOnKeyListener { _, keyCode, keyEvent ->
-            if (keyCode == KeyEvent.KEYCODE_BACK && keyEvent.action == ACTION_UP) {
-              view.context.onBackPressedDispatcherOwnerOrNull()
-                  ?.onBackPressedDispatcher
-                  ?.let {
-                    if (it.hasEnabledCallbacks()) it.onBackPressed()
-                  }
-              true
-            } else {
-              false
-            }
+        setOnKeyListener { _, keyCode, keyEvent ->
+          if (keyCode == KeyEvent.KEYCODE_BACK && keyEvent.action == ACTION_UP) {
+            view.context.onBackPressedDispatcherOwnerOrNull()
+              ?.onBackPressedDispatcher
+              ?.let {
+                if (it.hasEnabledCallbacks()) it.onBackPressed()
+              }
+            true
+          } else {
+            false
           }
         }
-        .run {
-          DialogRef(initialModalRendering, initialViewEnvironment, this, view)
-        }
+      }
+      .run {
+        DialogRef(initialModalRendering, initialViewEnvironment, this, view)
+      }
   }
 
   override fun updateDialog(dialogRef: DialogRef<Any>) {
@@ -118,14 +119,14 @@ public open class ModalViewContainer @JvmOverloads constructor(
     type: KClass<H>
   ) : com.squareup.workflow1.ui.ViewFactory<H>
   by BuilderViewFactory(
-      type = type,
-      viewConstructor = { initialRendering, initialEnv, context, _ ->
-        ModalViewContainer(context).apply {
-          this.id = id
-          layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
-          bindShowRendering(initialRendering, initialEnv, ::update)
-        }
+    type = type,
+    viewConstructor = { initialRendering, initialEnv, context, _ ->
+      ModalViewContainer(context).apply {
+        this.id = id
+        layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+        bindShowRendering(initialRendering, initialEnv, ::update)
       }
+    }
   )
 
   public companion object {
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
index 35f8daf941..daba8f1a3d 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
@@ -238,7 +238,7 @@ public class WorkflowViewStub @JvmOverloads constructor(
       WorkflowLifecycleOwner.get(it)?.destroyOnDetach()
     }
 
-    val newWorkflowView = screen.buildView(
+    val newViewHolder = screen.buildView(
       viewEnvironment,
       parent.context,
       parent
@@ -246,16 +246,16 @@ public class WorkflowViewStub @JvmOverloads constructor(
       WorkflowLifecycleOwner.installOn(view.view)
       doStart()
     }
-    newWorkflowView.start()
+    newViewHolder.start()
 
-    val newAndroidView = newWorkflowView.view
+    val newAndroidView = newViewHolder.view
 
     if (inflatedId != NO_ID) newAndroidView.id = inflatedId
     if (updatesVisibility) newAndroidView.visibility = visibility
     background?.let { newAndroidView.background = it }
     propagateSavedStateRegistryOwner(newAndroidView)
     replaceOldViewInParent(parent, newAndroidView)
-    delegateHolder = newWorkflowView
+    delegateHolder = newViewHolder
   }
 
   /**
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
index d7bcfd07a5..a78f9d4d28 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayDialogFactory.kt
@@ -11,6 +11,7 @@ import android.view.View
 import android.view.Window
 import android.view.WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
 import com.squareup.workflow1.ui.R
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -35,9 +36,9 @@ public abstract class ModalScreenOverlayDialogFactory<O : ScreenOverlay<*>>(
 
   /**
    * Called from [buildDialog]. Builds (but does not show) the [Dialog] to
-   * display a [contentView] built for a [ScreenOverlay.content].
+   * display a [content] view built for a [ScreenOverlay.content].
    */
-  public abstract fun buildDialogWithContentView(contentView: View): Dialog
+  public abstract fun buildDialogWithContent(content: ScreenViewHolder<*>): Dialog
 
   /**
    * If the [ScreenOverlay] displayed by a [dialog] created by this
@@ -61,7 +62,7 @@ public abstract class ModalScreenOverlayDialogFactory<O : ScreenOverlay<*>>(
     initialEnvironment: ViewEnvironment,
     context: Context
   ): Dialog {
-    val contentView = initialRendering.content.buildView(initialEnvironment, context).apply {
+    val contentHolder = initialRendering.content.buildView(initialEnvironment, context).apply {
       start()
       // If the content view has no backPressedHandler, add a no-op one to
       // ensure that the `onBackPressed` call below will not leak up to handlers
@@ -69,13 +70,13 @@ public abstract class ModalScreenOverlayDialogFactory<O : ScreenOverlay<*>>(
       if (view.backPressedHandler == null) view.backPressedHandler = { }
     }
 
-    return buildDialogWithContentView(contentView).also { dialog ->
+    return buildDialogWithContent(contentHolder).also { dialog ->
       val window = requireNotNull(dialog.window) { "Dialog must be attached to a window." }
 
       // There is no Dialog.getContentView method, and no reliable way to reverse
       // engineer one (no, android.R.id.content doesn't work). So we stick the
       // contentView in a tag here, where updateDialog can find it later.
-      window.peekDecorView()?.setTag(R.id.workflow_modal_dialog_content, contentView)
+      window.peekDecorView()?.setTag(R.id.workflow_modal_dialog_content, contentHolder)
         ?: throw IllegalStateException("Expected decorView to have been built.")
 
       val realWindowCallback = window.callback
@@ -85,15 +86,15 @@ public abstract class ModalScreenOverlayDialogFactory<O : ScreenOverlay<*>>(
             event.action == ACTION_UP
 
           return when {
-            isBackPress -> contentView.environment?.get(ModalScreenOverlayOnBackPressed)
-              ?.onBackPressed(contentView) == true
+            isBackPress -> contentHolder.environment[ModalScreenOverlayOnBackPressed]
+              .onBackPressed(contentHolder)
             else -> realWindowCallback.dispatchKeyEvent(event)
           }
         }
       }
 
       window.setFlags(FLAG_NOT_TOUCH_MODAL, FLAG_NOT_TOUCH_MODAL)
-      dialog.maintainBounds(contentView) { d, b -> updateBounds(d, Rect(b)) }
+      dialog.maintainBounds(contentHolder.view) { d, b -> updateBounds(d, Rect(b)) }
     }
   }
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayOnBackPressed.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayOnBackPressed.kt
index 3641e1f44e..7cc0cddc0f 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayOnBackPressed.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ModalScreenOverlayOnBackPressed.kt
@@ -1,6 +1,6 @@
 package com.squareup.workflow1.ui.container
 
-import android.view.View
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.ViewEnvironmentKey
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.container.ModalScreenOverlayOnBackPressed.Handler
@@ -26,11 +26,11 @@ public object ModalScreenOverlayOnBackPressed : ViewEnvironmentKey<Handler>(
      *
      * @return true if the back press event was consumed
      */
-    public fun onBackPressed(contentView: View): Boolean
+    public fun onBackPressed(content: ScreenViewHolder<*>): Boolean
   }
 
-  override val default: Handler = Handler { view ->
-    view.context.onBackPressedDispatcherOwnerOrNull()
+  override val default: Handler = Handler { viewHolder ->
+    viewHolder.view.context.onBackPressedDispatcherOwnerOrNull()
       ?.onBackPressedDispatcher
       ?.let {
         if (it.hasEnabledCallbacks()) it.onBackPressed()

From cf3efb06366273c20589ef561ee77247e577409f Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 11:34:21 -0800
Subject: [PATCH 06/12] wip: moved binding methods to view factory

---
 .../overviewdetail/OverviewDetailContainer.kt |   5 +-
 .../sample/poetryapp/PoemListScreen.kt        |   8 +-
 .../HelloBackButtonLayoutUpdater.kt           |   6 +-
 .../sample/poetry/StanzaListScreen.kt         |   7 +-
 .../squareup/sample/poetry/StanzaScreen.kt    |  12 +-
 .../sample/dungeon/BoardsListLayoutUpdater.kt |   6 +-
 .../sample/dungeon/GameLayoutUpdater.kt       |   6 +-
 .../squareup/sample/dungeon/LoadingBinding.kt |   8 +-
 .../ShakeableTimeMachineLayoutUpdater.kt      |   6 +-
 .../helloworkflowfragment/HelloRendering.kt   |  16 ++-
 .../sample/helloworkflow/HelloRendering.kt    |  16 ++-
 .../sample/stubvisibility/OuterRendering.kt   |  16 ++-
 .../authworkflow/AuthorizingViewFactory.kt    |  14 ++-
 .../sample/authworkflow/LoginViewFactory.kt   |  23 ++--
 .../authworkflow/SecondFactorViewFactory.kt   |  25 ++--
 .../gameworkflow/GameOverLayoutUpdater.kt     |  19 ++-
 .../gameworkflow/GamePlayViewFactory.kt       |  21 ++--
 .../sample/gameworkflow/NewGameViewFactory.kt |  25 ++--
 .../squareup/sample/todo/TodoEditorScreen.kt  |  11 +-
 .../squareup/sample/todo/TodoListsScreen.kt   |  31 +++--
 .../squareup/workflow1/ui/AndroidScreen.kt    |   2 +-
 .../workflow1/ui/BaseScreenViewHolder.kt      |   4 +-
 .../ui/DecorativeScreenViewFactory.kt         |  69 -----------
 .../workflow1/ui/LayoutScreenViewFactory.kt   |   7 +-
 .../workflow1/ui/ManualScreenViewFactory.kt   |  35 ++----
 .../workflow1/ui/ScreenViewFactory.kt         | 109 ++++++++++++++++--
 .../squareup/workflow1/ui/ScreenViewHolder.kt |  12 ++
 .../workflow1/ui/ScreenViewUpdater.kt         |  87 +-------------
 .../ui/ViewBindingScreenViewFactory.kt        |   2 +-
 29 files changed, 314 insertions(+), 294 deletions(-)
 delete mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
index 7dd6d44a02..0820c37b53 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
@@ -84,9 +84,8 @@ class OverviewDetailContainer(view: View) : ScreenViewUpdater<OverviewDetailScre
     stub.show(combined, viewEnvironment + (OverviewDetailConfig to Single))
   }
 
-  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewUpdater.bind(
-    layoutId = R.layout.overview_detail,
-    constructor = ::OverviewDetailContainer
+  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewFactory.ofLayout(R.layout.overview_detail,
+    { it: View -> OverviewDetailContainer(it) }
   ) {
     private const val OverviewBackStackKey = "overview"
   }
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
index e7bcf39ae3..02ebcd2617 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
@@ -12,6 +12,7 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overvie
 import com.squareup.sample.container.poetryapp.R
 import com.squareup.sample.poetry.model.Poem
 import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
@@ -22,10 +23,9 @@ data class PoemListScreen(
   val onPoemSelected: (Int) -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<PoemListScreen> {
-  override val viewFactory = ScreenViewUpdater.bind(
-    R.layout.list,
-    ::PoemListLayoutUpdater
-  )
+  override val viewFactory = ScreenViewFactory.ofLayout(
+    R.layout.list
+  ) { it: View -> PoemListLayoutUpdater(it) }
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
diff --git a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
index 679e0bcf0e..dbfb3d8152 100644
--- a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
+++ b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutUpdater.kt
@@ -15,9 +15,9 @@ data class HelloBackButtonScreen(
   val onClick: () -> Unit,
   val onBackPressed: (() -> Unit)?
 ) : AndroidScreen<HelloBackButtonScreen> {
-  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> = ScreenViewUpdater.bind(
-    R.layout.hello_back_button_layout, ::HelloBackButtonLayoutUpdater
-  )
+  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> = ScreenViewFactory.ofLayout(
+    R.layout.hello_back_button_layout
+  ) { it: View -> HelloBackButtonLayoutUpdater(it) }
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
index 0aaa566f71..9395c16b93 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
@@ -28,10 +28,9 @@ data class StanzaListScreen(
   val onExit: () -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<StanzaListScreen> {
-  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewUpdater.bind(
-    R.layout.list,
-    ::StanzaListLayoutUpdater
-  )
+  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewFactory.ofLayout(
+    R.layout.list
+  ) { it: View -> StanzaListLayoutUpdater(it) }
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
index 6ea53afde8..d907548756 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
@@ -32,10 +32,9 @@ data class StanzaScreen(
 ) : AndroidScreen<StanzaScreen>, Compatible {
   override val compatibilityKey = "$title: $stanzaNumber"
 
-  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewUpdater.bind(
-    R.layout.stanza_layout,
-    ::StanzaLayoutUpdater
-  )
+  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewFactory.ofLayout(
+    R.layout.stanza_layout
+  ) { it: View -> StanzaLayoutUpdater(it) }
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
@@ -114,8 +113,7 @@ private class StanzaLayoutUpdater(private val view: View) : ScreenViewUpdater<St
     setText(spans, SPANNABLE)
   }
 
-  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewUpdater.bind(
-      R.layout.stanza_layout,
-      ::StanzaLayoutUpdater
+  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewFactory.ofLayout(R.layout.stanza_layout,
+    { it: View -> StanzaLayoutUpdater(it) }
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
index e473856b3b..d27e7a5b30 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutUpdater.kt
@@ -12,7 +12,6 @@ import com.squareup.sample.dungeon.DungeonAppWorkflow.DisplayBoardsListScreen
 import com.squareup.sample.dungeon.board.Board
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -101,7 +100,8 @@ class BoardsListLayoutUpdater(rootView: View) : ScreenViewUpdater<DisplayBoardsL
     )
   }
 
-  companion object : ScreenViewFactory<DisplayBoardsListScreen> by bind(
-      R.layout.boards_list_layout, ::BoardsListLayoutUpdater
+  companion object : ScreenViewFactory<DisplayBoardsListScreen> by ScreenViewFactory.ofLayout(
+    R.layout.boards_list_layout,
+    { it: View -> BoardsListLayoutUpdater(it) }
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
index ca5f2d03f2..67d85f8aa9 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutUpdater.kt
@@ -12,7 +12,6 @@ import com.squareup.sample.dungeon.Direction.UP
 import com.squareup.sample.dungeon.GameWorkflow.GameRendering
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -66,7 +65,8 @@ class GameLayoutUpdater(view: View) : ScreenViewUpdater<GameRendering> {
     }
   }
 
-  companion object : ScreenViewFactory<GameRendering> by bind(
-      R.layout.game_layout, ::GameLayoutUpdater
+  companion object : ScreenViewFactory<GameRendering> by ScreenViewFactory.ofLayout(
+    R.layout.game_layout,
+    { it: View -> GameLayoutUpdater(it) }
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
index 4ec99d5991..fa9630cd8a 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
@@ -8,7 +8,6 @@ import androidx.annotation.StringRes
 import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
@@ -23,7 +22,12 @@ import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 inline fun <reified RenderingT : Screen> LoadingBinding(
   @StringRes loadingLabelRes: Int
 ): ScreenViewFactory<RenderingT> =
-  bind(R.layout.loading_layout) { view -> LoadingLayoutUpdater(loadingLabelRes, view) }
+  ScreenViewFactory.ofLayout(R.layout.loading_layout) { view: View ->
+    LoadingLayoutUpdater(
+      loadingLabelRes,
+      view
+    )
+  }
 
 @PublishedApi
 internal class LoadingLayoutUpdater<RenderingT : Screen>(
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
index 77cf285d3b..a5f25ccca0 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutUpdater.kt
@@ -9,7 +9,6 @@ import androidx.transition.TransitionManager
 import com.squareup.sample.timemachine.shakeable.internal.GlassFrameLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -87,7 +86,8 @@ class ShakeableTimeMachineLayoutUpdater(
 
   private fun Duration.toUiString(): String = toString()
 
-  companion object : ScreenViewFactory<ShakeableTimeMachineScreen> by bind(
-      R.layout.shakeable_time_machine_layout, ::ShakeableTimeMachineLayoutUpdater
+  companion object : ScreenViewFactory<ShakeableTimeMachineScreen> by ScreenViewFactory.ofLayout(
+    R.layout.shakeable_time_machine_layout,
+    { it: View -> ShakeableTimeMachineLayoutUpdater(it) }
   )
 }
diff --git a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
index d852aca4d0..8a614fae41 100644
--- a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
+++ b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.helloworkflowfragment
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.helloworkflowfragment.databinding.HelloGoodbyeLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
@@ -12,8 +14,16 @@ data class HelloRendering(
   val onClick: () -> Unit
 ) : AndroidScreen<HelloRendering> {
   override val viewFactory: ScreenViewFactory<HelloRendering> =
-    ScreenViewUpdater.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
-      helloMessage.text = "${r.message} Fragment"
-      helloMessage.setOnClickListener { r.onClick() }
+    ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+      HelloGoodbyeLayoutBinding.inflate(
+        inflater,
+        parent,
+        attachToParent
+      )
+    }) { binding ->
+      ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+        binding.helloMessage.text = "${rendering.message} Fragment"
+        binding.helloMessage.setOnClickListener { rendering.onClick() }
+      }
     }
 }
diff --git a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
index ed32e30053..6532e16763 100644
--- a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
+++ b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.helloworkflow
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.helloworkflow.databinding.HelloGoodbyeLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
@@ -12,8 +14,16 @@ data class HelloRendering(
   val onClick: () -> Unit
 ) : AndroidScreen<HelloRendering> {
   override val viewFactory: ScreenViewFactory<HelloRendering> =
-    ScreenViewUpdater.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
-      helloMessage.text = r.message
-      helloMessage.setOnClickListener { r.onClick() }
+    ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+      HelloGoodbyeLayoutBinding.inflate(
+        inflater,
+        parent,
+        attachToParent
+      )
+    }) { binding ->
+      ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+        binding.helloMessage.text = rendering.message
+        binding.helloMessage.setOnClickListener { rendering.onClick() }
+      }
     }
 }
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
index ab12418734..60ef5489fe 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.stubvisibility
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.stubvisibility.databinding.StubVisibilityLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
@@ -12,8 +14,16 @@ data class OuterRendering(
   val bottom: ClickyTextRendering
 ) : AndroidScreen<OuterRendering> {
   override val viewFactory: ScreenViewFactory<OuterRendering> =
-    ScreenViewUpdater.bind(StubVisibilityLayoutBinding::inflate) { rendering, env ->
-      shouldBeFilledStub.show(rendering.top, env)
-      shouldBeWrappedStub.show(rendering.bottom, env)
+    ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+      StubVisibilityLayoutBinding.inflate(
+        inflater,
+        parent,
+        attachToParent
+      )
+    }) { binding ->
+      ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+        binding.shouldBeFilledStub.show(rendering.top, viewEnvironment)
+        binding.shouldBeWrappedStub.show(rendering.bottom, viewEnvironment)
+      }
     }
 }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
index 4094c47823..5a1e8afa21 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.authworkflow
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.AuthorizingLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
@@ -7,6 +9,14 @@ import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val AuthorizingViewFactory: ScreenViewFactory<AuthorizingScreen> =
-  ScreenViewUpdater.bind(AuthorizingLayoutBinding::inflate) { rendering, _ ->
-    authorizingMessage.text = rendering.message
+  ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    AuthorizingLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { binding ->
+    ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+      binding.authorizingMessage.text = rendering.message
+    }
   }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
index f236542940..5c835f7311 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
@@ -1,19 +1,26 @@
 package com.squareup.sample.authworkflow
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.LoginLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val LoginViewFactory: ScreenViewFactory<LoginScreen> =
-  ScreenViewUpdater.bind(LoginLayoutBinding::inflate) { rendering, _ ->
-    loginErrorMessage.text = rendering.errorMessage
-
-    loginButton.setOnClickListener {
-      rendering.onLogin(loginEmail.text.toString(), loginPassword.text.toString())
+  ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    LoginLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { binding ->
+    ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+      binding.loginErrorMessage.text = rendering.errorMessage
+      binding.loginButton.setOnClickListener {
+        rendering.onLogin(binding.loginEmail.text.toString(), binding.loginPassword.text.toString())
+      }
+      binding.root.backPressedHandler = { rendering.onCancel() }
     }
-
-    root.backPressedHandler = { rendering.onCancel() }
   }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
index e513065f41..1a0e974535 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
@@ -1,20 +1,27 @@
 package com.squareup.sample.authworkflow
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.SecondFactorLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val SecondFactorViewFactory: ScreenViewFactory<SecondFactorScreen> =
-  ScreenViewUpdater.bind(SecondFactorLayoutBinding::inflate) { rendering, _ ->
-    root.backPressedHandler = { rendering.onCancel() }
-    secondFactorToolbar.setNavigationOnClickListener { rendering.onCancel() }
-
-    secondFactorErrorMessage.text = rendering.errorMessage
-
-    secondFactorSubmitButton.setOnClickListener {
-      rendering.onSubmit(secondFactor.text.toString())
+  ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    SecondFactorLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { binding ->
+    ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+      binding.root.backPressedHandler = { rendering.onCancel() }
+      binding.secondFactorToolbar.setNavigationOnClickListener { rendering.onCancel() }
+      binding.secondFactorErrorMessage.text = rendering.errorMessage
+      binding.secondFactorSubmitButton.setOnClickListener {
+        rendering.onSubmit(binding.secondFactor.text.toString())
+      }
     }
   }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
index d9fe7ec206..20d9ed6bd2 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutUpdater.kt
@@ -1,6 +1,8 @@
 package com.squareup.sample.gameworkflow
 
+import android.view.LayoutInflater
 import android.view.MenuItem
+import android.view.ViewGroup
 import androidx.appcompat.widget.Toolbar
 import com.squareup.sample.gameworkflow.Ending.Draw
 import com.squareup.sample.gameworkflow.Ending.Quitted
@@ -12,7 +14,6 @@ import com.squareup.sample.tictactoe.databinding.BoardBinding
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -102,7 +103,17 @@ internal class GameOverLayoutUpdater(
   }
 
   /** Note how easily we're sharing this layout with [GamePlayViewFactory]. */
-  companion object : ScreenViewFactory<GameOverScreen> by bind(
-      GamePlayLayoutBinding::inflate, ::GameOverLayoutUpdater
-  )
+  companion object : ScreenViewFactory<GameOverScreen> by ScreenViewFactory.ofViewBinding<BindingT, ScreenT>(
+    { inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+      GamePlayLayoutBinding.inflate(
+        inflater,
+        parent,
+        attachToParent
+      )
+    }) { binding ->
+    ScreenViewUpdater<ScreenT>
+    { rendering, viewEnvironment ->
+      GameOverLayoutUpdater(it)
+    }
+  }
 }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
index 025588fc37..1979870e9b 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
@@ -1,21 +1,28 @@
 package com.squareup.sample.gameworkflow
 
+import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val GamePlayViewFactory: ScreenViewFactory<GamePlayScreen> =
-  ScreenViewUpdater.bind(GamePlayLayoutBinding::inflate) { rendering, _ ->
-    renderBanner(rendering.gameState, rendering.playerInfo)
-    rendering.gameState.board.render(gamePlayBoard.root)
-
-    setCellClickListeners(gamePlayBoard.root, rendering.gameState, rendering.onClick)
-    root.backPressedHandler = rendering.onQuit
+  ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    GamePlayLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { binding ->
+    ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+      binding.renderBanner(rendering.gameState, rendering.playerInfo)
+      rendering.gameState.board.render(binding.gamePlayBoard.root)
+      setCellClickListeners(binding.gamePlayBoard.root, rendering.gameState, rendering.onClick)
+      binding.root.backPressedHandler = rendering.onQuit
+    }
   }
 
 private fun setCellClickListeners(
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
index 8ab5a1cc97..80e9b798fc 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
@@ -1,20 +1,27 @@
 package com.squareup.sample.gameworkflow
 
+import android.view.LayoutInflater
+import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.NewGameLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal val NewGameViewFactory: ScreenViewFactory<NewGameScreen> =
-  ScreenViewUpdater.bind(NewGameLayoutBinding::inflate) { rendering, _ ->
-    if (playerX.text.isBlank()) playerX.setText(rendering.defaultNameX)
-    if (playerO.text.isBlank()) playerO.setText(rendering.defaultNameO)
-
-    startGame.setOnClickListener {
-      rendering.onStartGame(playerX.text.toString(), playerO.text.toString())
+  ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    NewGameLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { binding ->
+    ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+      if (binding.playerX.text.isBlank()) binding.playerX.setText(rendering.defaultNameX)
+      if (binding.playerO.text.isBlank()) binding.playerO.setText(rendering.defaultNameO)
+      binding.startGame.setOnClickListener {
+        rendering.onStartGame(binding.playerX.text.toString(), binding.playerO.text.toString())
+      }
+      binding.root.backPressedHandler = { rendering.onCancel() }
     }
-
-    root.backPressedHandler = { rendering.onCancel() }
   }
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
index bd754bec29..0d6d759c66 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
@@ -2,13 +2,14 @@
 package com.squareup.sample.todo
 
 import android.content.Context.INPUT_METHOD_SERVICE
+import android.view.LayoutInflater
 import android.view.View
+import android.view.ViewGroup
 import android.view.inputmethod.InputMethodManager
 import com.squareup.sample.todo.databinding.TodoEditorLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.Compatible
 import com.squareup.workflow1.ui.ScreenViewUpdater
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
@@ -25,7 +26,13 @@ data class TodoEditorScreen(
 ) : AndroidScreen<TodoEditorScreen>, Compatible {
 
   override val compatibilityKey = Compatible.keyFor(this, "${session.id}")
-  override val viewFactory = bind(TodoEditorLayoutBinding::inflate, ::Updater)
+  override val viewFactory = ofViewBinding({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+    TodoEditorLayoutBinding.inflate(
+      inflater,
+      parent,
+      attachToParent
+    )
+  }) { Updater(it) }
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
index 5a2a8be7df..1aad4ebc8f 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
@@ -1,13 +1,14 @@
 package com.squareup.sample.todo
 
 import android.view.LayoutInflater
+import android.view.ViewGroup
 import android.widget.TextView
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.todo.databinding.TodoListsLayoutBinding
 import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.ScreenViewFactory
-import com.squareup.workflow1.ui.ScreenViewUpdater.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
@@ -26,17 +27,25 @@ data class TodoListsScreen(
   val selection: Int = -1
 ) : AndroidScreen<TodoListsScreen> {
   override val viewFactory: ScreenViewFactory<TodoListsScreen> =
-    bind(TodoListsLayoutBinding::inflate) { rendering, viewEnvironment ->
-      for ((index, list) in rendering.lists.withIndex()) {
-        addRow(
-          index,
-          list,
-          selectable = viewEnvironment[OverviewDetailConfig] == Overview,
-          selected = index == rendering.selection &&
-            viewEnvironment[OverviewDetailConfig] == Overview
-        ) { rendering.onRowClicked(index) }
+    ScreenViewFactory.ofViewBinding<BindingT, ScreenT>({ inflater: LayoutInflater, parent: ViewGroup?, attachToParent: Boolean ->
+      TodoListsLayoutBinding.inflate(
+        inflater,
+        parent,
+        attachToParent
+      )
+    }) { binding ->
+      ScreenViewUpdater<ScreenT> { rendering, viewEnvironment ->
+        for ((index, list) in rendering.lists.withIndex<TodoList>()) {
+          binding.addRow(
+            index,
+            list,
+            selectable = viewEnvironment[OverviewDetailConfig] == Overview,
+            selected = index == rendering.selection &&
+              viewEnvironment[OverviewDetailConfig] == Overview
+          ) { rendering.onRowClicked(index) }
+        }
+        binding.pruneDeadRowsFrom(rendering.lists.size)
       }
-      pruneDeadRowsFrom(rendering.lists.size)
     }
 }
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
index ad6a1c4f44..7b44ef48db 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
@@ -5,7 +5,7 @@ package com.squareup.workflow1.ui
  * via an appropriate [ScreenViewFactory] implementation.
  *
  * You will rarely, if ever, write a [ScreenViewFactory] yourself.  Instead
- * use [ScreenViewUpdater.bind] to work with XML layout resources, or
+ * use [ScreenViewUpdater.ofViewBinding] to work with XML layout resources, or
  * [BuilderViewFactory] to create views from code.  See [ScreenViewUpdater] for more
  * details.
  *
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
index 962688dbc0..70d7c78dff 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
@@ -7,7 +7,7 @@ internal class BaseScreenViewHolder<ScreenT: Screen>(
   private val initialRendering: ScreenT,
   private val initialViewEnvironment: ViewEnvironment,
   override val view: View,
-  private val runner: ScreenViewRunner<ScreenT>
+  private val updater: ScreenViewUpdater<ScreenT>
 ) : ScreenViewHolder<ScreenT> {
   lateinit var currentRendering: ScreenT
   lateinit var currentEnvironment: ViewEnvironment
@@ -24,6 +24,6 @@ internal class BaseScreenViewHolder<ScreenT: Screen>(
   override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
     currentRendering = screen
     currentEnvironment = environment
-    runner.showRendering(screen, environment)
+    updater.showRendering(screen, environment)
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
deleted file mode 100644
index fe11de5c04..0000000000
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
+++ /dev/null
@@ -1,69 +0,0 @@
-package com.squareup.workflow1.ui
-
-import android.content.Context
-import android.view.View
-import android.view.ViewGroup
-import kotlin.reflect.KClass
-
-@WorkflowUiExperimentalApi
-public class DecorativeScreenViewFactory<OuterT : Screen, InnerT : Screen>(
-  override val type: KClass<OuterT>,
-  private val map: (OuterT, ViewEnvironment) -> Pair<InnerT, ViewEnvironment>,
-  private val viewStarter: ViewStarter? = null,
-  private val doShowRendering: (
-    view: View,
-    innerShowRendering: ViewShowRendering<InnerT>,
-    outerRendering: OuterT,
-    env: ViewEnvironment
-  ) -> Unit = { _, innerShowRendering, outerRendering, viewEnvironment ->
-    val (innerRendering, processedEnv) = map(outerRendering, viewEnvironment)
-    innerShowRendering(innerRendering, processedEnv)
-  }
-) : ScreenViewFactory<OuterT> {
-
-  /**
-   * Convenience constructor for cases requiring no changes to the [ViewEnvironment].
-   */
-  public constructor(
-    type: KClass<OuterT>,
-    map: (OuterT) -> InnerT,
-    viewStarter: ViewStarter? = null,
-    doShowRendering: (
-      view: View,
-      innerShowRendering: ViewShowRendering<InnerT>,
-      outerRendering: OuterT,
-      env: ViewEnvironment
-    ) -> Unit = { _, innerShowRendering, outerRendering, viewEnvironment ->
-      innerShowRendering(map(outerRendering), viewEnvironment)
-    }
-  ) : this(
-    type,
-    map = { outer, viewEnvironment -> Pair(map(outer), viewEnvironment) },
-    viewStarter = viewStarter,
-    doShowRendering = doShowRendering
-  )
-
-  override fun buildView(
-    initialRendering: OuterT,
-    initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
-    container: ViewGroup?
-  ): View {
-    val (innerInitialRendering, processedInitialEnv) = map(initialRendering, initialViewEnvironment)
-
-    return innerInitialRendering.buildView(
-      processedInitialEnv,
-      contextForNewView,
-      container,
-      viewStarter
-    )
-      .also { view ->
-        val innerShowRendering: ViewShowRendering<InnerT> = view.getShowRendering()!!
-
-        view.bindShowRendering(
-          initialRendering,
-          processedInitialEnv
-        ) { rendering, env -> doShowRendering(view, innerShowRendering, rendering, env) }
-      }
-  }
-}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
index eeb8818f2b..077986ea11 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -6,11 +6,6 @@ import android.view.ViewGroup
 import androidx.annotation.LayoutRes
 import kotlin.reflect.KClass
 
-/**
- * A [ScreenViewFactory] that ties a [layout resource][layoutId] to a
- * [ViewRunner factory][updaterConstructor] function. See [ScreenViewUpdater] for
- * details.
- */
 @WorkflowUiExperimentalApi
 @PublishedApi
 internal class LayoutScreenViewFactory<ScreenT : Screen>(
@@ -31,7 +26,7 @@ internal class LayoutScreenViewFactory<ScreenT : Screen>(
       initialRendering = initialRendering,
       initialViewEnvironment = initialViewEnvironment,
       view = view,
-      runner = updaterConstructor(view)
+      updater = updaterConstructor(view)
     )
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
index 3ad39f6cd8..010ed73642 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
@@ -5,39 +5,22 @@ import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
-/**
- * A [ScreenViewFactory] that creates [View]s that need to be generated from code.
- * (Use [ScreenViewUpdater] to work with XML layout resources.)
- *
- *    data class MyScreen(): AndroidScreen<MyView> {
- *      val viewFactory = ManualScreenViewFactory(
- *          type = MyScreen::class,
- *          viewConstructor = { initialRendering, _, context, _ ->
- *            MyFrame(context).apply {
- *              layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
- *              bindShowRendering(initialRendering, ::update)
- *            }
- *      )
- *    }
- *
- *    private class MyFrame(context: Context) : FrameLayout(context, attributeSet) {
- *      private fun update(rendering:  MyScreen) { ... }
- *    }
- */
 @WorkflowUiExperimentalApi
-public class ManualScreenViewFactory<RenderingT : Screen>(
-  override val type: KClass<RenderingT>,
+@PublishedApi
+internal class ManualScreenViewFactory<ScreenT : Screen>(
+  override val type: KClass<ScreenT>,
   private val viewConstructor: (
-    initialRendering: RenderingT,
+    initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ) -> View
-) : ScreenViewFactory<RenderingT> {
+  ) -> ScreenViewHolder<ScreenT>
+) : ScreenViewFactory<ScreenT> {
   override fun buildView(
-    initialRendering: RenderingT,
+    initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
     contextForNewView: Context,
     container: ViewGroup?
-  ): View = viewConstructor(initialRendering, initialViewEnvironment, contextForNewView, container)
+  ): ScreenViewHolder<ScreenT> =
+    viewConstructor(initialRendering, initialViewEnvironment, contextForNewView, container)
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index 9b49f8bdde..15c399e148 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -3,6 +3,8 @@ package com.squareup.workflow1.ui
 import android.content.Context
 import android.view.View
 import android.view.ViewGroup
+import androidx.annotation.LayoutRes
+import androidx.viewbinding.ViewBinding
 import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.container.BackStackScreenViewFactory
 import com.squareup.workflow1.ui.container.BodyAndModalsContainer
@@ -11,24 +13,24 @@ import com.squareup.workflow1.ui.container.EnvironmentScreen
 import com.squareup.workflow1.ui.container.EnvironmentScreenViewFactory
 
 /**
- * Factory for [View] instances that can show renderings of type [ScreenT] : [Screen].
- *
- * Two concrete [ScreenViewFactory] implementations are provided:
- *
- *  - The various [bind][ScreenViewUpdater.bind] methods on [ScreenViewUpdater] allow easy use of
- *    Android XML layout resources and [AndroidX ViewBinding][androidx.viewbinding.ViewBinding].
- *
- *  - [ManualScreenViewFactory] allows views to be built from code.
+ * Factory for Android [View] instances that can show renderings of type [ScreenT] : [Screen].
  *
  * It's simplest to have your rendering classes implement [AndroidScreen] to associate
  * them with appropriate an appropriate [ScreenViewFactory]. For more flexibility, and to
  * avoid coupling your workflow directly to the Android runtime, see [ViewRegistry].
+ *
+ * - Use [ScreenViewFactory.ofViewBinding] to create a factory for an
+ *    [AndroidX ViewBinding][ViewBinding]
+ * - Use [ScreenViewFactory.ofLayout] or [ScreenViewFactory.ofStaticLayout] to create
+ *   a factory for an XML layout resource
+ * - Use [ScreenViewFactory.of] to create a factory entirely at runtime.
  */
 @WorkflowUiExperimentalApi
 public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<ScreenT> {
   /**
-   * Returns a View ready to display [initialRendering] (and any succeeding values)
-   * via [View.showRendering].
+   * Returns a [ScreenViewHolder] ready to display [initialRendering] (and any succeeding values).
+   * Callers of this method must call [ScreenViewHolder.start] exactly once before
+   * calling [ScreenViewHolder.showScreen].
    */
   public fun buildView(
     initialRendering: ScreenT,
@@ -36,11 +38,94 @@ public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<Screen
     contextForNewView: Context,
     container: ViewGroup? = null
   ): ScreenViewHolder<ScreenT>
+
+  public companion object {
+    /**
+     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
+     * to show renderings of type [ScreenT] : [Screen], using [a lambda][showRendering].
+     *
+     *    val HelloViewFactory: ScreenViewFactory<HelloScreen> =
+     *      ScreenViewUpdater.bind(HelloGoodbyeViewBinding::inflate) { rendering, viewEnvironment ->
+     *        helloMessage.text = rendering.message
+     *        helloMessage.setOnClickListener { rendering.onClick(Unit) }
+     *      }
+     *
+     * If you need to initialize your view before [showRendering] is called,
+     * implement [ScreenViewUpdater] and create a binding using the `bind` variant
+     * that accepts a `(ViewBinding) -> ScreenViewUpdater` function, below.
+     */
+    public inline fun <BindingT : ViewBinding, reified ScreenT : Screen> ofViewBinding(
+      noinline bindingInflater: ViewBindingInflater<BindingT>,
+      crossinline showRendering: BindingT.(ScreenT, ViewEnvironment) -> Unit
+    ): ScreenViewFactory<ScreenT> = ofViewBinding(bindingInflater) { binding ->
+      ScreenViewUpdater { rendering, viewEnvironment ->
+        binding.showRendering(rendering, viewEnvironment)
+      }
+    }
+
+    /**
+     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
+     * to show renderings of type [ScreenT] : [Screen], using a [ScreenViewUpdater]
+     * created by [constructor]. Handy if you need to perform some set up before
+     * [showRendering] is called.
+     *
+     *   class HelloScreenRunner(
+     *     private val binding: HelloGoodbyeViewBinding
+     *   ) : ScreenViewUpdater<HelloScreen> {
+     *
+     *     override fun showRendering(rendering: HelloScreen) {
+     *       binding.messageView.text = rendering.message
+     *       binding.messageView.setOnClickListener { rendering.onClick(Unit) }
+     *     }
+     *
+     *     companion object : ScreenViewFactory<HelloScreen> by bind(
+     *       HelloGoodbyeViewBinding::inflate, ::HelloScreenRunner
+     *     )
+     *   }
+     *
+     * If the view doesn't need to be initialized before [showRendering] is called,
+     * use the variant above which just takes a lambda.
+     */
+    public inline fun <BindingT : ViewBinding, reified ScreenT : Screen> ofViewBinding(
+      noinline bindingInflater: ViewBindingInflater<BindingT>,
+      noinline constructor: (BindingT) -> ScreenViewUpdater<ScreenT>
+    ): ScreenViewFactory<ScreenT> =
+      ViewBindingScreenViewFactory(ScreenT::class, bindingInflater, constructor)
+
+    /**
+     * Creates a [ScreenViewFactory] that inflates [layoutId] to show renderings of
+     * type [ScreenT]  : [Screen], using a [ScreenViewUpdater] created by [constructor].
+     * Avoids any use of [AndroidX ViewBinding][ViewBinding].
+     */
+    public inline fun <reified ScreenT : Screen> ofLayout(
+      @LayoutRes layoutId: Int,
+      noinline constructor: (View) -> ScreenViewUpdater<ScreenT>
+    ): ScreenViewFactory<ScreenT> =
+      LayoutScreenViewFactory(ScreenT::class, layoutId, constructor)
+
+    /**
+     * Creates a [ScreenViewFactory] that inflates [layoutId] to "show" renderings of type [ScreenT],
+     * with a no-op [ScreenViewUpdater]. Handy for showing static views, e.g. when prototyping.
+     */
+    @Suppress("unused")
+    public inline fun <reified ScreenT : Screen> ofStaticLayout(
+      @LayoutRes layoutId: Int
+    ): ScreenViewFactory<ScreenT> = ofLayout(layoutId) { ScreenViewUpdater { _, _ -> } }
+
+    /** Creates a [ScreenViewFactory] entirely from code. */
+    public inline fun <reified ScreenT : Screen> of(
+      noinline viewConstructor: (
+        initialRendering: ScreenT,
+        initialViewEnvironment: ViewEnvironment,
+        contextForNewView: Context,
+        container: ViewGroup?
+      ) -> ScreenViewHolder<ScreenT>
+    ): ScreenViewFactory<ScreenT> = ManualScreenViewFactory(ScreenT::class, viewConstructor)
+  }
 }
 
 /**
- * It is usually more convenient to use [WorkflowViewStub] or [DecorativeScreenViewFactory]
- * than to call this method directly.
+ * It is usually more convenient to use [WorkflowViewStub] than to call this method directly.
  *
  * Finds a [ScreenViewFactory] to create a [View] to display the receiving [Screen].
  * The caller is responsible for calling [View.start] on the new [View]. After that,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
index a2c8f30154..1f36aab17f 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -36,6 +36,18 @@ public interface ScreenViewHolder<ScreenT : Screen> {
   }
 }
 
+/** Wraps [view] in a [ScreenViewHolder], mainly for use from [ManualScreenViewFactory]. */
+@Suppress("FunctionName")
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenViewHolder(
+  initialRendering: ScreenT,
+  initialViewEnvironment: ViewEnvironment,
+  view: View,
+  updater: ScreenViewUpdater<ScreenT>
+): ScreenViewHolder<ScreenT> {
+  return BaseScreenViewHolder(initialRendering, initialViewEnvironment, view, updater)
+}
+
 @WorkflowUiExperimentalApi
 public fun ScreenViewHolder<*>.canShowScreen(screen: Screen): Boolean {
   return compatible(this.screen, screen)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
index 54a124c931..c8d96869cf 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewUpdater.kt
@@ -2,100 +2,19 @@ package com.squareup.workflow1.ui
 
 import android.content.Context
 import android.view.LayoutInflater
-import android.view.View
 import android.view.ViewGroup
-import androidx.annotation.LayoutRes
 import androidx.viewbinding.ViewBinding
 
 @WorkflowUiExperimentalApi
 public typealias ViewBindingInflater<BindingT> = (LayoutInflater, ViewGroup?, Boolean) -> BindingT
 
-/**
- * Function that updates the UI built by a  [ScreenViewFactory].
- *
- * If you're using [AndroidX ViewBinding][ViewBinding] you likely won't need to
- * implement this interface at all. For details, see the three overloads of [ScreenViewUpdater.bind].
- */
+/** Function that updates the UI built by a [ScreenViewFactory]. */
 @WorkflowUiExperimentalApi
-public fun interface ScreenViewUpdater<RenderingT : Screen> {
+public fun interface ScreenViewUpdater<ScreenT : Screen> {
   public fun showRendering(
-    rendering: RenderingT,
+    rendering: ScreenT,
     viewEnvironment: ViewEnvironment
   )
-
-  public companion object {
-    /**
-     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
-     * to show renderings of type [RenderingT] : [Screen], using [a lambda][showRendering].
-     *
-     *    val HelloViewFactory: ScreenViewFactory<HelloScreen> =
-     *      ScreenViewUpdater.bind(HelloGoodbyeViewBinding::inflate) { rendering, viewEnvironment ->
-     *        helloMessage.text = rendering.message
-     *        helloMessage.setOnClickListener { rendering.onClick(Unit) }
-     *      }
-     *
-     * If you need to initialize your view before [showRendering] is called,
-     * implement [ScreenViewUpdater] and create a binding using the `bind` variant
-     * that accepts a `(ViewBinding) -> ScreenViewUpdater` function, below.
-     */
-    public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
-      noinline bindingInflater: ViewBindingInflater<BindingT>,
-      crossinline showRendering: BindingT.(RenderingT, ViewEnvironment) -> Unit
-    ): ScreenViewFactory<RenderingT> = bind(bindingInflater) { binding ->
-      ScreenViewUpdater { rendering, viewEnvironment ->
-        binding.showRendering(rendering, viewEnvironment)
-      }
-    }
-
-    /**
-     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
-     * to show renderings of type [RenderingT] : [Screen], using a [ScreenViewUpdater]
-     * created by [constructor]. Handy if you need to perform some set up before
-     * [showRendering] is called.
-     *
-     *   class HelloScreenRunner(
-     *     private val binding: HelloGoodbyeViewBinding
-     *   ) : ScreenViewUpdater<HelloScreen> {
-     *
-     *     override fun showRendering(rendering: HelloScreen) {
-     *       binding.messageView.text = rendering.message
-     *       binding.messageView.setOnClickListener { rendering.onClick(Unit) }
-     *     }
-     *
-     *     companion object : ScreenViewFactory<HelloScreen> by bind(
-     *       HelloGoodbyeViewBinding::inflate, ::HelloScreenRunner
-     *     )
-     *   }
-     *
-     * If the view doesn't need to be initialized before [showRendering] is called,
-     * use the variant above which just takes a lambda.
-     */
-    public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
-      noinline bindingInflater: ViewBindingInflater<BindingT>,
-      noinline constructor: (BindingT) -> ScreenViewUpdater<RenderingT>
-    ): ScreenViewFactory<RenderingT> =
-      ViewBindingScreenViewFactory(RenderingT::class, bindingInflater, constructor)
-
-    /**
-     * Creates a [ScreenViewFactory] that inflates [layoutId] to show renderings of
-     * type [RenderingT]  : [Screen], using a [ScreenViewUpdater] created by [constructor].
-     * Avoids any use of [AndroidX ViewBinding][ViewBinding].
-     */
-    public inline fun <reified RenderingT : Screen> bind(
-      @LayoutRes layoutId: Int,
-      noinline constructor: (View) -> ScreenViewUpdater<RenderingT>
-    ): ScreenViewFactory<RenderingT> =
-      LayoutScreenViewFactory(RenderingT::class, layoutId, constructor)
-
-    /**
-     * Creates a [ScreenViewFactory] that inflates [layoutId] to "show" renderings of type [RenderingT],
-     * with a no-op [ScreenViewUpdater]. Handy for showing static views, e.g. when prototyping.
-     */
-    @Suppress("unused")
-    public inline fun <reified RenderingT : Screen> bindNoRunner(
-      @LayoutRes layoutId: Int
-    ): ScreenViewFactory<RenderingT> = bind(layoutId) { ScreenViewUpdater { _, _ -> } }
-  }
 }
 
 internal fun Context.viewBindingLayoutInflater(container: ViewGroup?) =
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
index 8974af0d5d..69d4cbf5b7 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -25,7 +25,7 @@ internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, ScreenT : Sc
       initialRendering,
       initialViewEnvironment,
       binding.root,
-      runner = updaterConstructor(binding)
+      updater = updaterConstructor(binding)
     )
   }
 }

From 66f28f573739c7de76cb428516ff7f98544686b8 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 11:38:35 -0800
Subject: [PATCH 07/12] wip: moved ViewStarter back to a more proper home

---
 .../workflow1/ui/AndroidViewRegistry.kt       | 13 +++++++++++-
 .../workflow1/ui/ScreenViewFactory.kt         | 20 -------------------
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt
index 52b765db0a..34d2544c3b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt
@@ -26,8 +26,19 @@ public fun <RenderingT : Any>
     )
 }
 
-@Deprecated("Use getEntryFor()")
 @WorkflowUiExperimentalApi
+@Deprecated("Use ScreenViewHolder.Starter")
+public fun interface ViewStarter {
+  /** Called from [View.start]. [doStart] must be invoked. */
+  public fun startView(
+    view: View,
+    doStart: () -> Unit
+  )
+}
+
+@Suppress("DeprecatedCallableAddReplaceWith")
+@WorkflowUiExperimentalApi
+@Deprecated("Use getEntryFor()")
 public fun <RenderingT : Any> ViewRegistry.getFactoryFor(
   renderingType: KClass<out RenderingT>
 ): ViewFactory<RenderingT>? {
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index 15c399e148..ce1982c5fd 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -148,26 +148,6 @@ public fun <ScreenT : Screen> ScreenT.buildView(
   )
 }
 
-/**
- * A wrapper for the function invoked when [View.start] is called, allowing for
- * last second initialization of a newly built [View]. Provided via [Screen.buildView]
- * or [DecorativeScreenViewFactory.viewStarter].
- *
- * While [View.getRendering] may be called from [startView], it is not safe to
- * assume that the type of the rendering retrieved matches the type the view was
- * originally built to display. [ScreenViewFactory] instances can be wrapped, and
- * renderings can be mapped to other types.
- */
-@WorkflowUiExperimentalApi
-@Deprecated("Use WorkflowView.Starter")
-public fun interface ViewStarter {
-  /** Called from [View.start]. [doStart] must be invoked. */
-  public fun startView(
-    view: View,
-    doStart: () -> Unit
-  )
-}
-
 @WorkflowUiExperimentalApi
 internal fun <ScreenT : Screen>
   ViewEnvironment.getViewFactoryForRendering(rendering: ScreenT): ScreenViewFactory<ScreenT> {

From f6ce9c253b795b6db99cd0fcdb1f94cba0d2efa8 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 12:41:47 -0800
Subject: [PATCH 08/12] wip: Manual thing is private

---
 .../sample/container/ScrimContainer.kt        |  38 +++---
 .../com/squareup/sample/dungeon/BoardView.kt  |  14 ++-
 .../stubvisibility/ClickyTextRendering.kt     |  27 ++---
 .../ModalViewContainerLifecycleActivity.kt    |  36 +++---
 .../workflow1/ui/modal/AlertContainer.kt      |  14 +--
 .../ui/WorkflowViewStubLifecycleActivity.kt   |  11 +-
 .../ui/WorkflowViewStubLifecycleTest.kt       | 108 +++++++++---------
 .../BackStackContainerLifecycleActivity.kt    |  27 +++--
 .../NoTransitionBackStackContainer.kt         |  16 ++-
 .../workflow1/ui/AsScreenViewFactory.kt       |  10 +-
 .../workflow1/ui/BuilderViewFactory.kt        |   2 +-
 .../workflow1/ui/DecorativeViewFactory.kt     |   2 +-
 .../squareup/workflow1/ui/ScreenViewHolder.kt |   8 +-
 .../workflow1/ui/ViewShowRendering.kt         |   2 +
 .../container/BackStackScreenViewFactory.kt   |  14 +--
 .../ui/container/BodyAndModalsContainer.kt    |  14 +--
 .../test/AbstractLifecycleTestActivity.kt     |  27 ++---
 17 files changed, 184 insertions(+), 186 deletions(-)

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/ScrimContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/ScrimContainer.kt
index e30b9f9837..ce7a49d9de 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/ScrimContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/ScrimContainer.kt
@@ -7,11 +7,10 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.core.content.ContextCompat
 import com.squareup.sample.container.panel.ScrimScreen
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.bindShowRendering
 
 /**
  * A view that renders only its first child, behind a smoke scrim if
@@ -33,7 +32,7 @@ internal class ScrimContainer @JvmOverloads constructor(
 
   private val child: View
     get() = getChildAt(0)
-        ?: error("Child must be set immediately upon creation.")
+      ?: error("Child must be set immediately upon creation.")
 
   var isDimmed: Boolean = false
     set(value) {
@@ -84,30 +83,29 @@ internal class ScrimContainer @JvmOverloads constructor(
       ValueAnimator.ofFloat(1f, 0f)
     }.apply {
       duration = resources.getInteger(android.R.integer.config_shortAnimTime)
-          .toLong()
+        .toLong()
       addUpdateListener { animation -> scrim.alpha = animation.animatedValue as Float }
       start()
     }
   }
 
   @OptIn(WorkflowUiExperimentalApi::class)
-  companion object : ScreenViewFactory<ScrimScreen<*>> by ManualScreenViewFactory(
-      type = ScrimScreen::class,
-      viewConstructor = { initialRendering, initialViewEnvironment, contextForNewView, _ ->
-        val stub = WorkflowViewStub(contextForNewView)
+  companion object : ScreenViewFactory<ScrimScreen<*>> by ScreenViewFactory.of(
+    viewConstructor = { initialRendering, initialViewEnvironment, contextForNewView, _ ->
+      val stub = WorkflowViewStub(contextForNewView)
 
-        ScrimContainer(contextForNewView)
-            .also { view ->
-              view.layoutParams = LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)
-              view.addView(stub)
+      ScrimContainer(contextForNewView)
+        .let { view ->
+          view.layoutParams = LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)
+          view.addView(stub)
 
-              view.bindShowRendering(
-                initialRendering, initialViewEnvironment
-              ) { rendering, environment ->
-                stub.show(rendering.content, environment)
-                view.isDimmed = rendering.dimmed
-              }
-            }
-      }
+          ScreenViewHolder(
+            initialRendering, initialViewEnvironment, view
+          ) { rendering, environment ->
+            stub.show(rendering.content, environment)
+            view.isDimmed = rendering.dimmed
+          }
+        }
+    }
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
index bdb070c080..4bb4919ecb 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
@@ -8,10 +8,9 @@ import android.graphics.Rect
 import android.view.View
 import androidx.core.content.ContextCompat
 import com.squareup.sample.dungeon.board.Board
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.bindShowRendering
 import kotlin.math.abs
 import kotlin.math.min
 
@@ -83,10 +82,15 @@ class BoardView(context: Context) : View(context) {
   }
 
   @OptIn(WorkflowUiExperimentalApi::class)
-  companion object : ScreenViewFactory<Board> by ManualScreenViewFactory(
-    type = Board::class,
+  companion object : ScreenViewFactory<Board> by ScreenViewFactory.of(
     viewConstructor = { initialRendering, initialEnv, contextForNewView, _ ->
       BoardView(contextForNewView)
-        .apply { bindShowRendering(initialRendering, initialEnv) { r, _ -> update(r) } }
+        .let { view ->
+          ScreenViewHolder(
+            initialRendering,
+            initialEnv,
+            view
+          ) { r, _ -> view.update(r) }
+        }
     })
 }
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
index 2a68a552a5..e18d07bb8d 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
@@ -9,9 +9,9 @@ import android.view.ViewGroup.LayoutParams
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.widget.TextView
 import com.squareup.workflow1.ui.AndroidScreen
-import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.bindShowRendering
 
 @OptIn(WorkflowUiExperimentalApi::class)
 data class ClickyTextRendering(
@@ -19,25 +19,26 @@ data class ClickyTextRendering(
   val visible: Boolean = true,
   val onClick: (() -> Unit)? = null
 ) : AndroidScreen<ClickyTextRendering> {
-  override val viewFactory = ManualScreenViewFactory(
-    type = ClickyTextRendering::class,
+  override val viewFactory = ScreenViewFactory.of<ClickyTextRendering>(
     viewConstructor = { initialRendering, initialEnv, context, _ ->
-      TextView(context).also { textView ->
+      TextView(context).let { textView ->
         textView.layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
         textView.gravity = CENTER
-
-        textView.bindShowRendering(initialRendering, initialEnv) { clickyText, _ ->
-          textView.text = clickyText.message
-          textView.isVisible = clickyText.visible
-          textView.setOnClickListener(
-            clickyText.onClick?.let { oc -> OnClickListener { oc() } }
-          )
-        }
+        ScreenViewHolder(initialRendering, initialEnv, textView) { r, _ -> textView.update(r) }
       }
     }
   )
 }
 
+@OptIn(WorkflowUiExperimentalApi::class)
+private fun TextView.update(clickyText: ClickyTextRendering) {
+  text = clickyText.message
+  isVisible = clickyText.visible
+  setOnClickListener(
+    clickyText.onClick?.let { oc -> OnClickListener { oc() } }
+  )
+}
+
 private var View.isVisible: Boolean
   get() = visibility == VISIBLE
   set(value) {
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
index 68b2541d6e..c603f5d294 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
+++ b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
@@ -6,16 +6,15 @@ import android.content.Context
 import android.view.View
 import android.view.ViewGroup
 import android.widget.FrameLayout
-import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.bindShowRendering
+import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.internal.test.AbstractLifecycleTestActivity
 import com.squareup.workflow1.ui.modal.HasModals
 import com.squareup.workflow1.ui.modal.ModalViewContainer
@@ -33,9 +32,11 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
       initialViewEnvironment: ViewEnvironment,
       contextForNewView: Context,
       container: ViewGroup?
-    ): View = View(contextForNewView).apply {
-      bindShowRendering(initialRendering, initialViewEnvironment) { _, _ -> /* Noop */ }
-    }
+    ) = ScreenViewHolder(
+      initialRendering,
+      initialViewEnvironment,
+      View(contextForNewView)
+    ) { _, _ -> /* Noop */ }
   }
 
   data class TestModals(
@@ -55,19 +56,22 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
   override val viewRegistry: ViewRegistry = ViewRegistry(
     ModalViewContainer.binding<TestModals>(),
     BaseRendering,
-    leafViewBinding(LeafRendering::class, lifecycleLoggingViewObserver { it.name }),
-    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
+    leafViewBinding(lifecycleLoggingViewObserver<LeafRendering> { it.name }),
+    ScreenViewFactory.of<RecurseRendering> { initialRendering,
       initialViewEnvironment,
-      contextForNewView, _ ->
-      FrameLayout(contextForNewView).also { container ->
+      contextForNewView,
+      _ ->
+      FrameLayout(contextForNewView).let { container ->
         val stub = WorkflowViewStub(contextForNewView)
         container.addView(stub)
-        container.bindShowRendering(
-          initialRendering,
-          initialViewEnvironment
-        ) { rendering, env ->
-          stub.show(asScreen(TestModals(listOf(rendering.wrapped))), env)
-        }
+        ScreenViewHolder(
+          initialRendering = initialRendering,
+          initialViewEnvironment = initialViewEnvironment,
+          view = container,
+          updater = { rendering, env ->
+            stub.show(asScreen(TestModals(listOf(rendering.wrapped))), env)
+          }
+        )
       }
     },
   )
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
index c534825294..9008621c6b 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
@@ -10,11 +10,10 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import androidx.annotation.StyleRes
 import androidx.appcompat.app.AlertDialog
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.container.R
 import com.squareup.workflow1.ui.modal.AlertScreen.Button
 import com.squareup.workflow1.ui.modal.AlertScreen.Button.NEGATIVE
@@ -83,14 +82,13 @@ public class AlertContainer @JvmOverloads constructor(
 
   private class AlertContainerViewFactory(
     @StyleRes private val dialogThemeResId: Int = 0
-  ) : ScreenViewFactory<AlertContainerScreen<*>> by ManualScreenViewFactory(
-    type = AlertContainerScreen::class,
+  ) : ScreenViewFactory<AlertContainerScreen<*>> by ScreenViewFactory.of(
     viewConstructor = { initialRendering, initialEnv, context, _ ->
       AlertContainer(context, dialogThemeResId = dialogThemeResId)
-        .apply {
-          id = R.id.workflow_alert_container
-          layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
-          bindShowRendering(initialRendering, initialEnv, ::update)
+        .let { view ->
+          view.id = R.id.workflow_alert_container
+          view.layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+          ScreenViewHolder(initialRendering, initialEnv, view, view::update)
         }
     }
   )
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
index 9a1754bd2e..75d21e2689 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
@@ -19,16 +19,17 @@ internal class WorkflowViewStubLifecycleActivity : AbstractLifecycleTestActivity
   }
 
   override val viewRegistry: ViewRegistry = ViewRegistry(
-    leafViewBinding(LeafRendering::class, lifecycleLoggingViewObserver { it.name }),
-    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
+    leafViewBinding<LeafRendering>(lifecycleLoggingViewObserver { it.name }),
+    ScreenViewFactory.of<RecurseRendering> { initialRendering,
       initialViewEnvironment,
       contextForNewView, _ ->
-      FrameLayout(contextForNewView).also { container ->
+      FrameLayout(contextForNewView).let { container ->
         val stub = WorkflowViewStub(contextForNewView)
         container.addView(stub)
-        container.bindShowRendering(
+        ScreenViewHolder(
           initialRendering,
-          initialViewEnvironment
+          initialViewEnvironment,
+          container
         ) { rendering, env ->
           stub.show(rendering.wrapped, env)
         }
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
index e480065127..c9a650b991 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
@@ -255,20 +255,19 @@ internal class WorkflowViewStubLifecycleTest {
     }
 
     data class RegistrySetter(val wrapped: TestRendering) : ViewRendering<RegistrySetter>() {
-      override val viewFactory: ScreenViewFactory<RegistrySetter> = ManualScreenViewFactory(
-        RegistrySetter::class
-      ) { initialRendering, initialViewEnvironment, context, _ ->
-        val stub = WorkflowViewStub(context)
-        ViewTreeSavedStateRegistryOwner.set(stub, expectedRegistryOwner)
+      override val viewFactory =
+        ScreenViewFactory.of<RegistrySetter> { initialRendering, initialViewEnvironment, context, _ ->
+          val stub = WorkflowViewStub(context)
+          ViewTreeSavedStateRegistryOwner.set(stub, expectedRegistryOwner)
 
-        FrameLayout(context).apply {
-          addView(stub)
+          FrameLayout(context).let { view ->
+            view.addView(stub)
 
-          bindShowRendering(initialRendering, initialViewEnvironment) { r, e ->
-            stub.show(r.wrapped, e)
+            ScreenViewHolder(initialRendering, initialViewEnvironment, view) { r, e ->
+              stub.show(r.wrapped, e)
+            }
           }
         }
-      }
     }
 
     var initialRegistryOwner: SavedStateRegistryOwner? = null
@@ -298,61 +297,58 @@ internal class WorkflowViewStubLifecycleTest {
       const val Tag = "counter"
     }
 
-    override val viewFactory: ScreenViewFactory<CounterRendering> = ManualScreenViewFactory(
-      CounterRendering::class
-    ) { initialRendering, initialViewEnvironment, context, _ ->
-      var counter = 0
-      Button(context).apply button@{
-        tag = Tag
+    override val viewFactory =
+      ScreenViewFactory.of<CounterRendering> { initialRendering, initialViewEnvironment, context, _ ->
+        var counter = 0
+        Button(context).apply button@{
+          tag = Tag
 
-        fun updateText() {
-          text = "Counter: $counter"
-        }
+          fun updateText() {
+            text = "Counter: $counter"
+          }
 
-        addOnAttachStateChangeListener(object : OnAttachStateChangeListener {
-          lateinit var registryOwner: SavedStateRegistryOwner
-          lateinit var lifecycleObserver: LifecycleObserver
-
-          override fun onViewAttachedToWindow(v: View) {
-            onViewAttached(this@button)
-            registryOwner = ViewTreeSavedStateRegistryOwner.get(this@button)!!
-            lifecycleObserver = object : LifecycleEventObserver {
-              override fun onStateChanged(
-                source: LifecycleOwner,
-                event: Event
-              ) {
-                if (event == ON_CREATE) {
-                  source.lifecycle.removeObserver(this)
-                  registryOwner.savedStateRegistry.consumeRestoredStateForKey("counter")
-                    ?.let { restoredState ->
-                      counter = restoredState.getInt("value")
-                      updateText()
-                    }
+          addOnAttachStateChangeListener(object : OnAttachStateChangeListener {
+            lateinit var registryOwner: SavedStateRegistryOwner
+            lateinit var lifecycleObserver: LifecycleObserver
+
+            override fun onViewAttachedToWindow(v: View) {
+              onViewAttached(this@button)
+              registryOwner = ViewTreeSavedStateRegistryOwner.get(this@button)!!
+              lifecycleObserver = object : LifecycleEventObserver {
+                override fun onStateChanged(
+                  source: LifecycleOwner,
+                  event: Event
+                ) {
+                  if (event == ON_CREATE) {
+                    source.lifecycle.removeObserver(this)
+                    registryOwner.savedStateRegistry.consumeRestoredStateForKey("counter")
+                      ?.let { restoredState ->
+                        counter = restoredState.getInt("value")
+                        updateText()
+                      }
+                  }
                 }
               }
+              registryOwner.lifecycle.addObserver(lifecycleObserver)
+              registryOwner.savedStateRegistry.registerSavedStateProvider("counter") {
+                Bundle().apply { putInt("value", counter) }
+              }
             }
-            registryOwner.lifecycle.addObserver(lifecycleObserver)
-            registryOwner.savedStateRegistry.registerSavedStateProvider("counter") {
-              Bundle().apply { putInt("value", counter) }
-            }
-          }
 
-          override fun onViewDetachedFromWindow(v: View) {
-            registryOwner.lifecycle.removeObserver(lifecycleObserver)
-            registryOwner.savedStateRegistry.unregisterSavedStateProvider("counter")
-          }
-        })
+            override fun onViewDetachedFromWindow(v: View) {
+              registryOwner.lifecycle.removeObserver(lifecycleObserver)
+              registryOwner.savedStateRegistry.unregisterSavedStateProvider("counter")
+            }
+          })
 
-        updateText()
-        setOnClickListener {
-          counter++
           updateText()
-        }
-
-        bindShowRendering(initialRendering, initialViewEnvironment) { _, _ ->
-          // Noop
+          setOnClickListener {
+            counter++
+            updateText()
+          }
+        }.let {
+          ScreenViewHolder(initialRendering, initialViewEnvironment, it) { _, _ -> /* no-op*/ }
         }
       }
-    }
   }
 }
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
index 524e138c87..d88cdef812 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
@@ -8,18 +8,17 @@ import androidx.test.core.app.ActivityScenario
 import androidx.test.espresso.assertion.ViewAssertions.matches
 import androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.withTagValue
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.Compatible
 import com.squareup.workflow1.ui.Screen
-import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
+import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
+import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
 import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.RecurseRendering
-import com.squareup.workflow1.ui.bindShowRendering
-import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.internal.test.AbstractLifecycleTestActivity
 import com.squareup.workflow1.ui.internal.test.inAnyView
 import org.hamcrest.Matcher
@@ -39,8 +38,11 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
       initialViewEnvironment: ViewEnvironment,
       contextForNewView: Context,
       container: ViewGroup?
-    ): View = View(contextForNewView).apply {
-      bindShowRendering(initialRendering, initialViewEnvironment) { _, _ -> /* Noop */ }
+    ) = ScreenViewHolder(
+      initialRendering,
+      initialViewEnvironment,
+      View(contextForNewView)
+    ) { _, _ -> /* Noop */
     }
   }
 
@@ -108,16 +110,17 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
   override val viewRegistry: ViewRegistry = ViewRegistry(
     NoTransitionBackStackContainer,
     BaseRendering,
-    leafViewBinding(LeafRendering::class, viewObserver, viewConstructor = ::ViewStateTestView),
-    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
+    leafViewBinding(viewObserver, viewConstructor = ::ViewStateTestView),
+    ScreenViewFactory.of<RecurseRendering> { initialRendering,
       initialViewEnvironment,
       contextForNewView, _ ->
-      FrameLayout(contextForNewView).also { container ->
+      FrameLayout(contextForNewView).let { container ->
         val stub = WorkflowViewStub(contextForNewView)
         container.addView(stub)
-        container.bindShowRendering(
+        ScreenViewHolder(
           initialRendering,
-          initialViewEnvironment
+          initialViewEnvironment,
+          container
         ) { rendering, env ->
           stub.show(rendering.wrappedBackstack.toBackstackWithBase(), env)
         }
@@ -153,6 +156,6 @@ internal fun ActivityScenario<BackStackContainerLifecycleActivity>.viewForScreen
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal fun waitForScreen(name: String) {
- inAnyView(withTagValue(equalTo(name)) as Matcher<View>)
+  inAnyView(withTagValue(equalTo(name)) as Matcher<View>)
     .check(matches(isCompletelyDisplayed()))
 }
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
index 026848fd26..4d6e364ea2 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
@@ -3,13 +3,12 @@ package com.squareup.workflow1.ui.container.fixtures
 import android.content.Context
 import android.view.View
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
-import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.R
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.container.BackStackContainer
 import com.squareup.workflow1.ui.container.BackStackScreen
-import com.squareup.workflow1.ui.R
 
 /**
  * A subclass of [BackStackContainer] that disables transitions to make it simpler to test the
@@ -24,14 +23,13 @@ internal class NoTransitionBackStackContainer(context: Context) : BackStackConta
   }
 
   companion object : ScreenViewFactory<BackStackScreen<*>>
-  by ManualScreenViewFactory(
-    type = BackStackScreen::class,
+  by ScreenViewFactory.of(
     viewConstructor = { initialRendering, initialEnv, context, _ ->
       NoTransitionBackStackContainer(context)
-        .apply {
-          id = R.id.workflow_back_stack_container
-          layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
-          bindShowRendering(initialRendering, initialEnv, ::update)
+        .let { view ->
+          view.id = R.id.workflow_back_stack_container
+          view.layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
+          ScreenViewHolder(initialRendering, initialEnv, view, view::update)
         }
     }
   )
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt
index 3b3e40f8d1..36d08ca1ee 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt
@@ -3,8 +3,7 @@ package com.squareup.workflow1.ui
 @WorkflowUiExperimentalApi
 @Suppress("DEPRECATION")
 internal object AsScreenViewFactory : ScreenViewFactory<AsScreen<*>>
-by ManualScreenViewFactory(
-  type = AsScreen::class,
+by ScreenViewFactory.of(
   viewConstructor = { initialRendering, initialViewEnvironment, context, container ->
     initialViewEnvironment[ViewRegistry]
       .buildView(
@@ -12,12 +11,13 @@ by ManualScreenViewFactory(
         initialViewEnvironment,
         context,
         container
-      ).also { view ->
+      ).let { view ->
         val legacyShowRendering = view.getShowRendering<Any>()!!
 
-        view.bindShowRendering(
+        ScreenViewHolder(
           initialRendering,
-          initialViewEnvironment
+          initialViewEnvironment,
+          view
         ) { rendering, env -> legacyShowRendering(rendering.rendering, env) }
       }
   }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
index e18aa37185..74327aff5d 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
@@ -6,7 +6,7 @@ import android.view.ViewGroup
 import kotlin.reflect.KClass
 
 @Suppress("DEPRECATION")
-@Deprecated("Use ManualScreenViewFactory")
+@Deprecated("Use ScreenViewFactory.of")
 @WorkflowUiExperimentalApi
 public class BuilderViewFactory<RenderingT : Any>(
   override val type: KClass<RenderingT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
index aee909a446..44dd2f44c9 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
@@ -109,7 +109,7 @@ import kotlin.reflect.KClass
  * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
  */
 @Suppress("DEPRECATION")
-@Deprecated("Use ManualScreenViewFactory")
+@Deprecated("Use ScreenViewFactory.of")
 @WorkflowUiExperimentalApi
 public class DecorativeViewFactory<OuterT : Any, InnerT : Any>(
   override val type: KClass<OuterT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
index 1f36aab17f..2272358bb1 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -36,7 +36,7 @@ public interface ScreenViewHolder<ScreenT : Screen> {
   }
 }
 
-/** Wraps [view] in a [ScreenViewHolder], mainly for use from [ManualScreenViewFactory]. */
+/** Wraps [view] in a [ScreenViewHolder], mainly for use from [ScreenViewFactory.of]. */
 @Suppress("FunctionName")
 @WorkflowUiExperimentalApi
 public fun <ScreenT : Screen> ScreenViewHolder(
@@ -68,7 +68,7 @@ public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withStarter(
 public fun <ScreenT : Screen, ScreenU : Screen> ScreenViewHolder<ScreenT>.mapRenderings(
   transform: (ScreenU) -> ScreenT
 ): ScreenViewHolder<ScreenU> {
-  return object: ScreenViewHolder<ScreenU> {
+  return object : ScreenViewHolder<ScreenU> {
     lateinit var unmapped: ScreenU
 
     override val screen: ScreenU
@@ -94,8 +94,8 @@ public fun <ScreenT : Screen, ScreenU : Screen> ScreenViewHolder<ScreenT>.mapRen
 @WorkflowUiExperimentalApi
 public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.mapEnvironment(
   updater: (ViewEnvironment) -> ViewEnvironment
-): ScreenViewHolder<ScreenT>{
-  return object: ScreenViewHolder<ScreenT> by this {
+): ScreenViewHolder<ScreenT> {
+  return object : ScreenViewHolder<ScreenT> by this {
     override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
       this@mapEnvironment.showScreen(screen, updater(environment))
     }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
index 9b9a9d295e..45c2eda109 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
@@ -28,7 +28,9 @@ public typealias ViewShowRendering<RenderingT> =
  * @see ViewFactory
  * @see DecorativeViewFactory
  */
+@Suppress("DeprecatedCallableAddReplaceWith")
 @WorkflowUiExperimentalApi
+@Deprecated("Use ScreenViewHolder")
 public fun <RenderingT : Any> View.bindShowRendering(
   initialRendering: RenderingT,
   initialViewEnvironment: ViewEnvironment,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt
index 6708071272..6887785494 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt
@@ -2,22 +2,20 @@ package com.squareup.workflow1.ui.container
 
 import android.view.ViewGroup.LayoutParams
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.R
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.bindShowRendering
 
 @WorkflowUiExperimentalApi
 internal object BackStackScreenViewFactory : ScreenViewFactory<BackStackScreen<*>>
-by ManualScreenViewFactory(
-  type = BackStackScreen::class,
+by ScreenViewFactory.of(
   viewConstructor = { initialRendering, initialEnv, context, _ ->
     BackStackContainer(context)
-      .apply {
-        id = R.id.workflow_back_stack_container
-        layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
-        bindShowRendering(initialRendering, initialEnv, ::update)
+      .let { view ->
+        view.id = R.id.workflow_back_stack_container
+        view.layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
+        ScreenViewHolder(initialRendering, initialEnv, view, view::update)
       }
   }
 )
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
index 8b37b6f6fe..40b69ca16b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
@@ -12,13 +12,12 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.view.ViewTreeObserver.OnGlobalLayoutListener
 import android.widget.FrameLayout
-import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.BaseScreenViewHolder
 import com.squareup.workflow1.ui.R
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.environment
 import com.squareup.workflow1.ui.getRendering
 import com.squareup.workflow1.ui.showRendering
@@ -167,14 +166,13 @@ internal class BodyAndModalsContainer @JvmOverloads constructor(
   }
 
   companion object : ScreenViewFactory<BodyAndModalsScreen<*, *>>
-  by ManualScreenViewFactory(
-    type = BodyAndModalsScreen::class,
+  by ScreenViewFactory.of(
     viewConstructor = { initialRendering, initialEnv, context, _ ->
       BodyAndModalsContainer(context)
-        .apply {
-          id = R.id.workflow_body_and_modals_container
-          layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
-          bindShowRendering(initialRendering, initialEnv, ::update)
+        .let { view ->
+          view.id = R.id.workflow_body_and_modals_container
+          view.layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
+          BaseScreenViewHolder(initialRendering, initialEnv, view, view::update)
         }
     }
   )
diff --git a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
index 5e7115d128..9878e189b5 100644
--- a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
+++ b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
@@ -11,14 +11,13 @@ import androidx.lifecycle.Lifecycle.Event
 import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.ViewTreeLifecycleOwner
-import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.bindShowRendering
 import kotlin.reflect.KClass
 
 /**
@@ -89,19 +88,18 @@ public abstract class AbstractLifecycleTestActivity : WorkflowUiTestActivity() {
     lifecycleEvents += message
   }
 
-  protected fun <R : Screen> leafViewBinding(
-    type: KClass<R>,
+  protected inline fun <reified R : Screen> leafViewBinding(
     viewObserver: ViewObserver<R>,
-    viewConstructor: (Context) -> LeafView<R> = ::LeafView
+    noinline viewConstructor: (Context) -> LeafView<R> = ::LeafView
   ): ScreenViewFactory<R> =
-    ManualScreenViewFactory(type) { initialRendering, initialViewEnvironment, context, _ ->
-      viewConstructor(context).apply {
-        this.viewObserver = viewObserver
-        viewObserver.onViewCreated(this, initialRendering)
-
-        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
-          this.rendering = rendering
-          viewObserver.onShowRendering(this, rendering)
+    ScreenViewFactory.of { initialRendering, initialViewEnvironment, context, _ ->
+      viewConstructor(context).let { view ->
+        view.viewObserver = viewObserver
+        viewObserver.onViewCreated(view, initialRendering)
+
+        ScreenViewHolder(initialRendering, initialViewEnvironment, view) { rendering, _ ->
+          view.rendering = rendering
+          viewObserver.onShowRendering(view, rendering)
         }
       }
     }
@@ -179,11 +177,10 @@ public abstract class AbstractLifecycleTestActivity : WorkflowUiTestActivity() {
     context: Context
   ) : FrameLayout(context) {
 
-    internal var viewObserver: ViewObserver<R>? = null
+    public var viewObserver: ViewObserver<R>? = null
 
     // We can't rely on getRendering() in case it's wrapped with Named.
     public lateinit var rendering: R
-      internal set
 
     private val lifecycleObserver = LifecycleEventObserver { _, event ->
       viewObserver?.onViewTreeLifecycleStateChanged(rendering, event)

From 5c1645fb984428bd55872f5dc2b4233acbce576d Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 14:22:30 -0800
Subject: [PATCH 09/12] wip: nearly there, ported all the decorators

---
 .../sample/container/BackButtonViewFactory.kt | 50 ++++++++++++-------
 .../workflow1/ui/DecorativeViewFactory.kt     |  2 +-
 .../workflow1/ui/NamedScreenViewFactory.kt    |  7 ++-
 .../workflow1/ui/ScreenViewFactory.kt         |  2 +-
 .../squareup/workflow1/ui/ScreenViewHolder.kt | 47 ++++++++++++-----
 .../container/EnvironmentScreenViewFactory.kt | 25 ++++++----
 6 files changed, 87 insertions(+), 46 deletions(-)

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
index 7e4ba2b328..0ba16c7e95 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
@@ -1,31 +1,43 @@
 package com.squareup.sample.container
 
-import com.squareup.workflow1.ui.DecorativeScreenViewFactory
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.acceptRenderings
 import com.squareup.workflow1.ui.backPressedHandler
+import com.squareup.workflow1.ui.buildView
+import com.squareup.workflow1.ui.withShowScreen
 
 /**
- * [ScreenViewFactory] that performs the work required by [BackButtonScreen].
+ * [ScreenViewFactory] that performs the work required by [BackButtonScreen], demonstrating
+ * some fancy [ScreenViewHolder][com.squareup.workflow1.ui.ScreenViewHolder] tricks in
+ * the process.
  */
 @WorkflowUiExperimentalApi
-object BackButtonViewFactory : ScreenViewFactory<BackButtonScreen<*>>
-by DecorativeScreenViewFactory(
-  type = BackButtonScreen::class,
-  map = { outer -> outer.wrapped },
-  doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
-    if (!outerRendering.override) {
-      // Place our handler before invoking innerShowRendering, so that
-      // its later calls to view.backPressedHandler will take precedence
-      // over ours.
-      view.backPressedHandler = outerRendering.onBackPressed
-    }
+val BackButtonViewFactory: ScreenViewFactory<BackButtonScreen<*>> =
+  ScreenViewFactory.of { initialRenderingT, initialViewEnvironment, context, container ->
+    initialRenderingT.wrapped
+      // Build the view for the wrapped rendering.
+      .buildView(initialViewEnvironment, context, container)
+      // Transform it to accept BackButtonScreen directly
+      .acceptRenderings<Screen, BackButtonScreen<*>> { backButtonScreen -> backButtonScreen.wrapped }
+      // Replace the showScreen method with one that can do a bit of pre- and post-processing
+      // on the view.
+      .withShowScreen { backButtonScreen, viewEnvironment ->
+        if (!backButtonScreen.override) {
+          // Place our handler before invoking the real showRendering method, so that
+          // its later calls to view.backPressedHandler will take precedence
+          // over ours.
+          view.backPressedHandler = backButtonScreen.onBackPressed
+        }
 
-    innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
+        // The receiver of this lambda is the one that received the withShowScreen call,
+        // so we're able to call the "real" showScreen method.
+        showScreen(backButtonScreen, viewEnvironment)
 
-    if (outerRendering.override) {
-      // Place our handler after invoking innerShowRendering, so that ours wins.
-      view.backPressedHandler = outerRendering.onBackPressed
-    }
+        if (backButtonScreen.override) {
+          // Place our handler after invoking innerShowRendering, so that ours wins.
+          view.backPressedHandler = backButtonScreen.onBackPressed
+        }
+      }
   }
-)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
index 44dd2f44c9..ef8b40d3c5 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
@@ -109,7 +109,7 @@ import kotlin.reflect.KClass
  * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
  */
 @Suppress("DEPRECATION")
-@Deprecated("Use ScreenViewFactory.of")
+@Deprecated("Use ScreenViewFactory.of and the extension methods on ScreenViewHolder")
 @WorkflowUiExperimentalApi
 public class DecorativeViewFactory<OuterT : Any, InnerT : Any>(
   override val type: KClass<OuterT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
index ddff8051a3..479e4f8af0 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
@@ -5,5 +5,8 @@ package com.squareup.workflow1.ui
  * to the factory for [NamedScreen.wrapped].
  */
 @WorkflowUiExperimentalApi
-internal object NamedScreenViewFactory : ScreenViewFactory<NamedScreen<*>>
-by DecorativeScreenViewFactory(NamedScreen::class, { named -> named.wrapped })
+internal val NamedScreenViewFactory: ScreenViewFactory<NamedScreen<*>> =
+  ScreenViewFactory.of { initialRendering, initialViewEnvironment, context, container ->
+    initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+      .acceptRenderings { named -> named.wrapped }
+  }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index ce1982c5fd..cb84a7ae6c 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -117,7 +117,7 @@ public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<Screen
       noinline viewConstructor: (
         initialRendering: ScreenT,
         initialViewEnvironment: ViewEnvironment,
-        contextForNewView: Context,
+        context: Context,
         container: ViewGroup?
       ) -> ScreenViewHolder<ScreenT>
     ): ScreenViewFactory<ScreenT> = ManualScreenViewFactory(ScreenT::class, viewConstructor)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
index 2272358bb1..fed8994ab0 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -64,40 +64,61 @@ public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withStarter(
   }
 }
 
+/**
+ * @param onShowScreen Function to be called in place of the receiver's
+ * [ScreenViewHolder.showScreen] method. When invoked, `this` is the
+ * original [ScreenViewHolder] that received the [withShowScreen] call,
+ * so [onShowScreen] has access to the original [ScreenViewHolder.showScreen] method.
+ */
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withShowScreen(
+  onShowScreen: ScreenViewHolder<ScreenT>.(ScreenT, ViewEnvironment) -> Unit
+): ScreenViewHolder<ScreenT> {
+  return object : ScreenViewHolder<ScreenT> by this {
+    override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
+      this@withShowScreen.onShowScreen(screen, environment)
+    }
+  }
+}
+
+/**
+ * Transforms the [ScreenViewHolder.showScreen] method of the receiver to accept [NewS]
+ * instead of [OriginalS], by applying the given [transform] function.
+ */
 @WorkflowUiExperimentalApi
-public fun <ScreenT : Screen, ScreenU : Screen> ScreenViewHolder<ScreenT>.mapRenderings(
-  transform: (ScreenU) -> ScreenT
-): ScreenViewHolder<ScreenU> {
-  return object : ScreenViewHolder<ScreenU> {
-    lateinit var unmapped: ScreenU
+public fun <OriginalS : Screen, NewS : Screen> ScreenViewHolder<OriginalS>.acceptRenderings(
+  transform: (NewS) -> OriginalS
+): ScreenViewHolder<NewS> {
+  return object : ScreenViewHolder<NewS> {
+    lateinit var unmapped: NewS
 
-    override val screen: ScreenU
+    override val screen: NewS
       get() = unmapped
 
     override val environment: ViewEnvironment
-      get() = this@mapRenderings.environment
+      get() = this@acceptRenderings.environment
 
     override val view: View
-      get() = this@mapRenderings.view
+      get() = this@acceptRenderings.view
 
     override fun start() {
-      this@mapRenderings.start()
+      this@acceptRenderings.start()
     }
 
-    override fun showScreen(screen: ScreenU, environment: ViewEnvironment) {
+    override fun showScreen(screen: NewS, environment: ViewEnvironment) {
       unmapped = screen
-      this@mapRenderings.showScreen(transform(screen), environment)
+      this@acceptRenderings.showScreen(transform(screen), environment)
     }
   }
 }
 
 @WorkflowUiExperimentalApi
-public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.mapEnvironment(
+public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.updateEnvironment(
   updater: (ViewEnvironment) -> ViewEnvironment
 ): ScreenViewHolder<ScreenT> {
   return object : ScreenViewHolder<ScreenT> by this {
     override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
-      this@mapEnvironment.showScreen(screen, updater(environment))
+      this@updateEnvironment.showScreen(screen, updater(environment))
     }
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
index c07a482b06..cf33fe1732 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
@@ -1,18 +1,23 @@
 package com.squareup.workflow1.ui.container
 
-import com.squareup.workflow1.ui.DecorativeScreenViewFactory
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.acceptRenderings
+import com.squareup.workflow1.ui.buildView
 import com.squareup.workflow1.ui.updateFrom
+import com.squareup.workflow1.ui.withShowScreen
 
 @WorkflowUiExperimentalApi
-internal object EnvironmentScreenViewFactory : ScreenViewFactory<EnvironmentScreen<*>>
-by DecorativeScreenViewFactory(
-  type = EnvironmentScreen::class,
-  map = { withEnvironment, inheritedEnvironment ->
-    Pair(
-      withEnvironment.screen,
-      inheritedEnvironment.updateFrom(withEnvironment.viewEnvironment)
-    )
+internal val EnvironmentScreenViewFactory: ScreenViewFactory<EnvironmentScreen<*>> =
+  ScreenViewFactory.of { initialRendering, initialViewEnvironment, context, container ->
+    initialRendering.screen
+      // Build the view for the wrapped rendering.
+      .buildView(initialViewEnvironment, context, container)
+      // Transform it to accept EnvironmentScreen directly.
+      .acceptRenderings<Screen, EnvironmentScreen<*>> { it.screen }
+      // When showScreen is called, enhance the viewEnvironment with the one in environmentScreen.
+      .withShowScreen { environmentScreen, viewEnvironment ->
+        showScreen(environmentScreen, viewEnvironment.updateFrom(environmentScreen.viewEnvironment))
+      }
   }
-)

From 72d0d123f13c33aabddb622dc8a7bdecf76ea5ae Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 14:53:18 -0800
Subject: [PATCH 10/12] wip: Holy shit it works.

---
 .../sample/container/BackButtonViewFactory.kt    |  6 +++---
 .../container/panel/PanelOverlayDialogFactory.kt |  8 ++++----
 .../ui/DecorativeScreenViewFactoryTest.kt        |  2 +-
 .../workflow1/ui/BaseScreenViewHolder.kt         |  4 ++--
 .../workflow1/ui/NamedScreenViewFactory.kt       |  2 +-
 .../squareup/workflow1/ui/ScreenViewHolder.kt    | 10 ++++++----
 .../squareup/workflow1/ui/WorkflowViewStub.kt    | 16 +++++++---------
 .../ui/container/BodyAndModalsContainer.kt       |  7 +++----
 .../ui/container/EnvironmentScreenViewFactory.kt |  3 +--
 9 files changed, 28 insertions(+), 30 deletions(-)

diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
index 0ba16c7e95..635fc963ae 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
@@ -15,12 +15,12 @@ import com.squareup.workflow1.ui.withShowScreen
  */
 @WorkflowUiExperimentalApi
 val BackButtonViewFactory: ScreenViewFactory<BackButtonScreen<*>> =
-  ScreenViewFactory.of { initialRenderingT, initialViewEnvironment, context, container ->
-    initialRenderingT.wrapped
+  ScreenViewFactory.of { initialRendering, initialViewEnvironment, context, container ->
+    initialRendering.wrapped
       // Build the view for the wrapped rendering.
       .buildView(initialViewEnvironment, context, container)
       // Transform it to accept BackButtonScreen directly
-      .acceptRenderings<Screen, BackButtonScreen<*>> { backButtonScreen -> backButtonScreen.wrapped }
+      .acceptRenderings(initialRendering) { backButtonScreen -> backButtonScreen.wrapped }
       // Replace the showScreen method with one that can do a bit of pre- and post-processing
       // on the view.
       .withShowScreen { backButtonScreen, viewEnvironment ->
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
index f896eb47e4..34da57d713 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelOverlayDialogFactory.kt
@@ -4,8 +4,8 @@ import android.app.Dialog
 import android.graphics.Rect
 import android.graphics.drawable.ColorDrawable
 import android.util.TypedValue
-import android.view.View
 import com.squareup.sample.container.R
+import com.squareup.workflow1.ui.ScreenViewHolder
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.container.ModalScreenOverlayDialogFactory
 import com.squareup.workflow1.ui.container.setBounds
@@ -17,10 +17,10 @@ import com.squareup.workflow1.ui.container.setBounds
 internal object PanelOverlayDialogFactory : ModalScreenOverlayDialogFactory<PanelOverlay<*>>(
   type = PanelOverlay::class
 ) {
-  override fun buildDialogWithContent(content: View): Dialog {
-    val context = content.context
+  override fun buildDialogWithContent(content: ScreenViewHolder<*>): Dialog {
+    val context = content.view.context
     return Dialog(context, R.style.PanelDialog).also { dialog ->
-      dialog.setContentView(content)
+      dialog.setContentView(content.view)
 
       // Welcome to Android. Nothing workflow-related here, this is just how one
       // finds the window background color for the theme. I sure hope it's better in Compose.
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
index b14c273762..f280b23c96 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
@@ -21,7 +21,7 @@ internal class DecorativeScreenViewFactoryTest {
         initialViewEnvironment: ViewEnvironment,
         contextForNewView: Context,
         container: ViewGroup?
-      ): View = InnerView(contextForNewView).apply {
+      ): RView = InnerView(contextForNewView).apply {
         bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
           events += "inner showRendering $rendering"
         }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
index 70d7c78dff..c23e553542 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
@@ -9,8 +9,8 @@ internal class BaseScreenViewHolder<ScreenT: Screen>(
   override val view: View,
   private val updater: ScreenViewUpdater<ScreenT>
 ) : ScreenViewHolder<ScreenT> {
-  lateinit var currentRendering: ScreenT
-  lateinit var currentEnvironment: ViewEnvironment
+  private var currentRendering: ScreenT = initialRendering
+  private var currentEnvironment: ViewEnvironment = initialViewEnvironment
 
   override val screen: ScreenT
     get() = currentRendering
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
index 479e4f8af0..4222b04a93 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
@@ -8,5 +8,5 @@ package com.squareup.workflow1.ui
 internal val NamedScreenViewFactory: ScreenViewFactory<NamedScreen<*>> =
   ScreenViewFactory.of { initialRendering, initialViewEnvironment, context, container ->
     initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
-      .acceptRenderings { named -> named.wrapped }
+      .acceptRenderings(initialRendering) { named -> named.wrapped }
   }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
index fed8994ab0..fe0c5ff2a7 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -83,17 +83,19 @@ public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withShowScreen(
 
 /**
  * Transforms the [ScreenViewHolder.showScreen] method of the receiver to accept [NewS]
- * instead of [OriginalS], by applying the given [transform] function.
+ * instead of [OriginalS], by applying the [given function][transform] to convert
+ * [NewS] to [OriginalS].
  */
 @WorkflowUiExperimentalApi
 public fun <OriginalS : Screen, NewS : Screen> ScreenViewHolder<OriginalS>.acceptRenderings(
+  initialRendering: NewS,
   transform: (NewS) -> OriginalS
 ): ScreenViewHolder<NewS> {
   return object : ScreenViewHolder<NewS> {
-    lateinit var unmapped: NewS
+    var untransformed: NewS = initialRendering
 
     override val screen: NewS
-      get() = unmapped
+      get() = untransformed
 
     override val environment: ViewEnvironment
       get() = this@acceptRenderings.environment
@@ -106,7 +108,7 @@ public fun <OriginalS : Screen, NewS : Screen> ScreenViewHolder<OriginalS>.accep
     }
 
     override fun showScreen(screen: NewS, environment: ViewEnvironment) {
-      unmapped = screen
+      untransformed = screen
       this@acceptRenderings.showScreen(transform(screen), environment)
     }
   }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
index daba8f1a3d..e9b703ad7f 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
@@ -70,11 +70,11 @@ public class WorkflowViewStub @JvmOverloads constructor(
   defStyleRes: Int = 0
 ) : View(context, attributeSet, defStyle, defStyleRes) {
   /** Returns null if [update] hasn't been called yet. */
-  private val delegateOrNull: View?
+  public val delegateHolderOrNull: ScreenViewHolder<Screen>?
     get() {
       // can be null when called from the constructor.
       @Suppress("UNNECESSARY_SAFE_CALL")
-      return delegateHolder?.view?.takeUnless { it === this }
+      return delegateHolder?.takeUnless { it.view === this }
     }
 
   public var delegateHolder: ScreenViewHolder<Screen> = object : ScreenViewHolder<Screen> {
@@ -161,16 +161,14 @@ public class WorkflowViewStub @JvmOverloads constructor(
    */
   override fun setVisibility(visibility: Int) {
     super.setVisibility(visibility)
-    delegateOrNull?.takeUnless { it == this }?.let {
-      it.visibility = visibility
-    }
+    delegateHolderOrNull?.let { it.view.visibility = visibility }
   }
 
   /**
    * Returns the visibility of the delegate, or of this stub if [show] has not yet been called.
    */
   override fun getVisibility(): Int {
-    return delegateOrNull?.visibility ?: super.getVisibility()
+    return delegateHolderOrNull?.view?.visibility ?: super.getVisibility()
   }
 
   /**
@@ -180,7 +178,7 @@ public class WorkflowViewStub @JvmOverloads constructor(
    */
   override fun setBackground(background: Drawable?) {
     super.setBackground(background)
-    if (background != null) delegateOrNull?.background = background
+    if (background != null) delegateHolderOrNull?.view?.background = background
   }
 
   @Deprecated("Use show()", ReplaceWith("show(rendering, viewEnvironment)"))
@@ -234,8 +232,8 @@ public class WorkflowViewStub @JvmOverloads constructor(
     // WorkflowLifecycleOwner on this view, this get() call will return the WLO owned by that
     // parent. We noop in that case since destroying that lifecycle is our parent's responsibility
     // in that case, not ours.
-    delegateOrNull?.let {
-      WorkflowLifecycleOwner.get(it)?.destroyOnDetach()
+    delegateHolderOrNull?.let {
+      WorkflowLifecycleOwner.get(it.view)?.destroyOnDetach()
     }
 
     val newViewHolder = screen.buildView(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
index 40b69ca16b..ee72f2bc2e 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BodyAndModalsContainer.kt
@@ -18,9 +18,6 @@ import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.environment
-import com.squareup.workflow1.ui.getRendering
-import com.squareup.workflow1.ui.showRendering
 import kotlinx.coroutines.flow.MutableStateFlow
 
 @WorkflowUiExperimentalApi
@@ -96,7 +93,9 @@ internal class BodyAndModalsContainer @JvmOverloads constructor(
     viewTreeObserver.addOnGlobalLayoutListener(boundsListener)
     // Ugly, but here in case a strange parent detaches and re-attaches us.
     // https://github.com/square/workflow-kotlin/issues/314
-    showRendering(getRendering()!!, environment!!)
+    baseViewStub.delegateHolderOrNull?.let {
+      it.showScreen(it.screen, it.environment)
+    }
   }
 
   override fun onDetachedFromWindow() {
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
index cf33fe1732..390dfaff9b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/EnvironmentScreenViewFactory.kt
@@ -1,6 +1,5 @@
 package com.squareup.workflow1.ui.container
 
-import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.acceptRenderings
@@ -15,7 +14,7 @@ internal val EnvironmentScreenViewFactory: ScreenViewFactory<EnvironmentScreen<*
       // Build the view for the wrapped rendering.
       .buildView(initialViewEnvironment, context, container)
       // Transform it to accept EnvironmentScreen directly.
-      .acceptRenderings<Screen, EnvironmentScreen<*>> { it.screen }
+      .acceptRenderings(initialRendering) { it.screen }
       // When showScreen is called, enhance the viewEnvironment with the one in environmentScreen.
       .withShowScreen { environmentScreen, viewEnvironment ->
         showScreen(environmentScreen, viewEnvironment.updateFrom(environmentScreen.viewEnvironment))

From 8b57396f44236b8474af2baf7a9753832a389a8b Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Fri, 7 Jan 2022 16:15:15 -0800
Subject: [PATCH 11/12] wip: ported the test, failing

---
 .../ModalViewContainerLifecycleActivity.kt    |   4 +-
 .../workflow1/ui/modal/ModalViewContainer.kt  |   2 +-
 ...FactoryTest.kt => ScreenViewHolderTest.kt} | 171 ++++++++----------
 .../BackStackContainerLifecycleActivity.kt    |   4 +-
 .../workflow1/ui/LayoutScreenViewFactory.kt   |   4 +-
 .../workflow1/ui/ManualScreenViewFactory.kt   |   5 +-
 .../workflow1/ui/ScreenViewFactory.kt         |   6 +-
 .../squareup/workflow1/ui/ScreenViewHolder.kt |   4 +-
 .../ui/ViewBindingScreenViewFactory.kt        |   4 +-
 .../ui/container/BackStackContainer.kt        |   2 +-
 .../workflow1/ui/ScreenViewFactoryTest.kt     |   2 +-
 11 files changed, 93 insertions(+), 115 deletions(-)
 rename workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/{DecorativeScreenViewFactoryTest.kt => ScreenViewHolderTest.kt} (50%)

diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
index c603f5d294..17bd1514d8 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
+++ b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
@@ -30,12 +30,12 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
     override fun buildView(
       initialRendering: BaseRendering,
       initialViewEnvironment: ViewEnvironment,
-      contextForNewView: Context,
+      context: Context,
       container: ViewGroup?
     ) = ScreenViewHolder(
       initialRendering,
       initialViewEnvironment,
-      View(contextForNewView)
+      View(context)
     ) { _, _ -> /* Noop */ }
   }
 
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
index 4e4076b0d1..52ed331c72 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
@@ -67,7 +67,7 @@ public open class ModalViewContainer @JvmOverloads constructor(
     val view = asScreen(initialModalRendering)
       .buildView(
         viewEnvironment = initialViewEnvironment,
-        contextForNewView = this.context,
+        context = this.context,
         container = this
       )
       .let { holder ->
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/ScreenViewHolderTest.kt
similarity index 50%
rename from workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/ScreenViewHolderTest.kt
index f280b23c96..c98fced2d3 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/ScreenViewHolderTest.kt
@@ -2,48 +2,39 @@ package com.squareup.workflow1.ui
 
 import android.content.Context
 import android.view.View
-import android.view.ViewGroup
 import androidx.test.platform.app.InstrumentationRegistry
 import com.google.common.truth.Truth.assertThat
 import org.junit.Test
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal class DecorativeScreenViewFactoryTest {
+internal class ScreenViewHolderTest {
   private val instrumentation = InstrumentationRegistry.getInstrumentation()
 
   @Test fun viewStarter_is_only_call_to_showRendering() {
     val events = mutableListOf<String>()
 
-    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
-      override val type = InnerRendering::class
-      override fun buildView(
-        initialRendering: InnerRendering,
-        initialViewEnvironment: ViewEnvironment,
-        contextForNewView: Context,
-        container: ViewGroup?
-      ): RView = InnerView(contextForNewView).apply {
-        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
-          events += "inner showRendering $rendering"
+    val innerViewFactory =
+      ScreenViewFactory.of<InnerRendering> { initialRendering, initialViewEnvironment, context, _ ->
+        ScreenViewHolder(initialRendering, initialViewEnvironment, InnerView(context)) { s, _ ->
+          events += "inner showRendering $s"
         }
       }
-    }
 
     val envString = object : ViewEnvironmentKey<String>(String::class) {
       override val default: String get() = "Not set"
     }
 
-    val outerViewFactory = DecorativeScreenViewFactory(
-      type = OuterRendering::class,
-      map = { outer, env ->
-        val enhancedEnv = env + (envString to "Updated environment")
-        Pair(outer.wrapped, enhancedEnv)
-      },
-      viewStarter = { view, doStart ->
-        events += "viewStarter ${view.getRendering<Any>()} ${view.environment!![envString]}"
-        doStart()
-        events += "exit viewStarter"
+    val outerViewFactory = ScreenViewFactory
+      .of<OuterRendering> { initialRendering, initialViewEnvironment, context, container ->
+        initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+          .acceptRenderings(initialRendering) { initialRendering.wrapped }
+          .withStarter { viewHolder, doStart ->
+            events += "viewStarter ${viewHolder.screen} ${viewHolder.environment[envString]}"
+            doStart()
+            events += "exit viewStarter"
+          }
       }
-    )
+
     val viewRegistry = ViewRegistry(innerViewFactory, outerViewFactory)
     val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
 
@@ -63,27 +54,23 @@ internal class DecorativeScreenViewFactoryTest {
   @Test fun initial_doShowRendering_calls_wrapped_showRendering() {
     val events = mutableListOf<String>()
 
-    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
-      override val type = InnerRendering::class
-      override fun buildView(
-        initialRendering: InnerRendering,
-        initialViewEnvironment: ViewEnvironment,
-        contextForNewView: Context,
-        container: ViewGroup?
-      ): View = InnerView(contextForNewView).apply {
-        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
-          events += "inner showRendering $rendering"
+    val innerViewFactory =
+      ScreenViewFactory.of<InnerRendering> { initialRendering, initialViewEnvironment, context, _ ->
+        ScreenViewHolder(initialRendering, initialViewEnvironment, InnerView(context)) { s, _ ->
+          events += "inner showRendering $s"
         }
       }
-    }
-    val outerViewFactory = DecorativeScreenViewFactory(
-      type = OuterRendering::class,
-      map = { outer -> outer.wrapped },
-      doShowRendering = { _, innerShowRendering, outerRendering, env ->
-        events += "doShowRendering $outerRendering"
-        innerShowRendering(outerRendering.wrapped, env)
+
+    val outerViewFactory = ScreenViewFactory
+      .of<OuterRendering> { initialRendering, initialViewEnvironment, context, container ->
+        initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+          .acceptRenderings(initialRendering) { it.wrapped }
+          .withShowScreen { outerRendering, viewEnvironment ->
+            events += "doShowRendering $outerRendering"
+            showScreen(outerRendering, viewEnvironment)
+          }
       }
-    )
+
     val viewRegistry = ViewRegistry(innerViewFactory, outerViewFactory)
     val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
 
@@ -102,50 +89,46 @@ internal class DecorativeScreenViewFactoryTest {
   @Test fun double_wrapping_only_calls_showRendering_once() {
     val events = mutableListOf<String>()
 
-    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
-      override val type = InnerRendering::class
-      override fun buildView(
-        initialRendering: InnerRendering,
-        initialViewEnvironment: ViewEnvironment,
-        contextForNewView: Context,
-        container: ViewGroup?
-      ): View = InnerView(contextForNewView).apply {
-        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
-          events += "inner showRendering $rendering"
+    val innerViewFactory = ScreenViewFactory
+      .of<InnerRendering> { initialRendering, initialViewEnvironment, context, _ ->
+        ScreenViewHolder(initialRendering, initialViewEnvironment, InnerView(context)) { s, _ ->
+          events += "inner showRendering $s"
         }
       }
-    }
 
     val envString = object : ViewEnvironmentKey<String>(String::class) {
       override val default: String get() = "Not set"
     }
 
-    val outerViewFactory = DecorativeScreenViewFactory(
-      type = OuterRendering::class,
-      map = { outer, env ->
-        val enhancedEnv = env + (envString to "Outer Updated environment" +
-          " SHOULD NOT SEE THIS! It will be clobbered by WayOutRendering")
-        Pair(outer.wrapped, enhancedEnv)
-      },
-      viewStarter = { view, doStart ->
-        events += "outer viewStarter ${view.getRendering<Any>()} ${view.environment!![envString]}"
-        doStart()
-        events += "exit outer viewStarter"
+    val outerViewFactory =
+      ScreenViewFactory.of<OuterRendering> { initialRendering, initialViewEnvironment, context, container ->
+        initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+          .acceptRenderings(initialRendering) { it.wrapped }
+          .updateEnvironment { env ->
+            env + (envString to "Outer Updated environment" +
+              " SHOULD NOT SEE THIS! It will be clobbered by WayOutRendering")
+          }
+          .withStarter { viewHolder, doStart ->
+            events += "outer viewStarter ${viewHolder.screen} ${viewHolder.environment[envString]}"
+            doStart()
+            events += "exit outer viewStarter"
+          }
       }
-    )
 
-    val wayOutViewFactory = DecorativeScreenViewFactory(
-      type = WayOutRendering::class,
-      map = { wayOut, env ->
-        val enhancedEnv = env + (envString to "Way Out Updated environment triumphs over all")
-        Pair(wayOut.wrapped, enhancedEnv)
-      },
-      viewStarter = { view, doStart ->
-        events += "way out viewStarter ${view.getRendering<Any>()} ${view.environment!![envString]}"
-        doStart()
-        events += "exit way out viewStarter"
+    val wayOutViewFactory = ScreenViewFactory
+      .of<WayOutRendering> { initialRendering, initialViewEnvironment, context, container ->
+        initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+          .acceptRenderings(initialRendering) { it.wrapped }
+          .updateEnvironment { env ->
+            env + (envString to "Way Out Updated environment triumphs over all")
+          }
+          .withStarter { viewHolder, doStart ->
+            events += "way out viewStarter ${viewHolder.screen} ${viewHolder.environment[envString]}"
+            doStart()
+            events += "exit way out viewStarter"
+          }
       }
-    )
+
     val viewRegistry = ViewRegistry(innerViewFactory, outerViewFactory, wayOutViewFactory)
     val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
 
@@ -178,37 +161,33 @@ internal class DecorativeScreenViewFactoryTest {
   @Test fun subsequent_showRendering_calls_wrapped_showRendering() {
     val events = mutableListOf<String>()
 
-    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
-      override val type = InnerRendering::class
-      override fun buildView(
-        initialRendering: InnerRendering,
-        initialViewEnvironment: ViewEnvironment,
-        contextForNewView: Context,
-        container: ViewGroup?
-      ): View = InnerView(contextForNewView).apply {
-        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
-          events += "inner showRendering $rendering"
+    val innerViewFactory =
+      ScreenViewFactory.of<InnerRendering> { initialRendering, initialViewEnvironment, context, _ ->
+        ScreenViewHolder(initialRendering, initialViewEnvironment, InnerView(context)) { s, _ ->
+          events += "inner showRendering $s"
         }
       }
-    }
-    val outerViewFactory = DecorativeScreenViewFactory(
-      type = OuterRendering::class,
-      map = { outer -> outer.wrapped },
-      doShowRendering = { _, innerShowRendering, outerRendering, env ->
-        events += "doShowRendering $outerRendering"
-        innerShowRendering(outerRendering.wrapped, env)
+
+    val outerViewFactory = ScreenViewFactory
+      .of<OuterRendering> { initialRendering, initialViewEnvironment, context, container ->
+        initialRendering.wrapped.buildView(initialViewEnvironment, context, container)
+          .acceptRenderings(initialRendering) { it.wrapped }
+          .withShowScreen { outerRendering, viewEnvironment ->
+            events += "doShowRendering $outerRendering"
+            showScreen(outerRendering, viewEnvironment)
+          }
       }
-    )
+
     val viewRegistry = ViewRegistry(innerViewFactory, outerViewFactory)
     val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
 
-    val view = OuterRendering("out1", InnerRendering("in1")).buildView(
+    val viewHolder = OuterRendering("out1", InnerRendering("in1")).buildView(
       viewEnvironment,
       instrumentation.context
     ).apply { start() }
     events.clear()
 
-    view.showRendering(OuterRendering("out2", InnerRendering("in2")), viewEnvironment)
+    viewHolder.showScreen(OuterRendering("out2", InnerRendering("in2")), viewEnvironment)
 
     assertThat(events).containsExactly(
       "doShowRendering OuterRendering(outerData=out2, wrapped=InnerRendering(innerData=in2))",
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
index d88cdef812..e350d47059 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
@@ -36,12 +36,12 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
     override fun buildView(
       initialRendering: BaseRendering,
       initialViewEnvironment: ViewEnvironment,
-      contextForNewView: Context,
+      context: Context,
       container: ViewGroup?
     ) = ScreenViewHolder(
       initialRendering,
       initialViewEnvironment,
-      View(contextForNewView)
+      View(context)
     ) { _, _ -> /* Noop */
     }
   }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
index 077986ea11..53907c3dca 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -16,11 +16,11 @@ internal class LayoutScreenViewFactory<ScreenT : Screen>(
   override fun buildView(
     initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
+    context: Context,
     container: ViewGroup?
   ): ScreenViewHolder<ScreenT> {
     val view =
-      contextForNewView.viewBindingLayoutInflater(container).inflate(layoutId, container, false)
+      context.viewBindingLayoutInflater(container).inflate(layoutId, container, false)
 
     return BaseScreenViewHolder(
       initialRendering = initialRendering,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
index 010ed73642..1390fddbe9 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
@@ -1,7 +1,6 @@
 package com.squareup.workflow1.ui
 
 import android.content.Context
-import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
@@ -19,8 +18,8 @@ internal class ManualScreenViewFactory<ScreenT : Screen>(
   override fun buildView(
     initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
+    context: Context,
     container: ViewGroup?
   ): ScreenViewHolder<ScreenT> =
-    viewConstructor(initialRendering, initialViewEnvironment, contextForNewView, container)
+    viewConstructor(initialRendering, initialViewEnvironment, context, container)
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
index cb84a7ae6c..827eba1402 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -35,7 +35,7 @@ public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<Screen
   public fun buildView(
     initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
+    context: Context,
     container: ViewGroup? = null
   ): ScreenViewHolder<ScreenT>
 
@@ -140,11 +140,11 @@ public interface ScreenViewFactory<ScreenT : Screen> : ViewRegistry.Entry<Screen
 @WorkflowUiExperimentalApi
 public fun <ScreenT : Screen> ScreenT.buildView(
   viewEnvironment: ViewEnvironment,
-  contextForNewView: Context,
+  context: Context,
   container: ViewGroup? = null
 ): ScreenViewHolder<ScreenT> {
   return viewEnvironment.getViewFactoryForRendering(this).buildView(
-    this, viewEnvironment, contextForNewView, container
+    this, viewEnvironment, context, container
   )
 }
 
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
index fe0c5ff2a7..f4090894c8 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewHolder.kt
@@ -55,11 +55,11 @@ public fun ScreenViewHolder<*>.canShowScreen(screen: Screen): Boolean {
 
 @WorkflowUiExperimentalApi
 public fun <ScreenT : Screen> ScreenViewHolder<ScreenT>.withStarter(
-  viewStarter: ScreenViewHolder.Starter<ScreenT>
+  starter: ScreenViewHolder.Starter<ScreenT>
 ): ScreenViewHolder<ScreenT> {
   return object : ScreenViewHolder<ScreenT> by this {
     override fun start() {
-      viewStarter.startView(this@withStarter, this@withStarter::start)
+      starter.startView(this@withStarter, this@withStarter::start)
     }
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
index 69d4cbf5b7..87800872da 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -15,11 +15,11 @@ internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, ScreenT : Sc
   override fun buildView(
     initialRendering: ScreenT,
     initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
+    context: Context,
     container: ViewGroup?
   ): ScreenViewHolder<ScreenT> {
     val binding = bindingInflater(
-      contextForNewView.viewBindingLayoutInflater(container), container, false
+      context.viewBindingLayoutInflater(container), container, false
     )
     return BaseScreenViewHolder(
       initialRendering,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
index 39e00d4bc9..79cab56c9e 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
@@ -97,7 +97,7 @@ public open class BackStackContainer @JvmOverloads constructor(
 
     val newView = named.top.buildView(
       viewEnvironment = environment,
-      contextForNewView = this.context,
+      context = this.context,
       container = this
     ).withStarter { view, doStart ->
       WorkflowLifecycleOwner.installOn(view.view)
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ScreenViewFactoryTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ScreenViewFactoryTest.kt
index d650b901f9..5a4606d2ed 100644
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ScreenViewFactoryTest.kt
+++ b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ScreenViewFactoryTest.kt
@@ -67,7 +67,7 @@ internal class ScreenViewFactoryTest {
     override fun buildView(
       initialRendering: T,
       initialViewEnvironment: ViewEnvironment,
-      contextForNewView: Context,
+      context: Context,
       container: ViewGroup?
     ): View {
       called = true

From 118450c344e09c3dcc65e443c3d3aefe0b5b4136 Mon Sep 17 00:00:00 2001
From: Ray Ryan <ray@squareup.com>
Date: Mon, 10 Jan 2022 09:39:15 -0800
Subject: [PATCH 12/12] wip: tryinig final class instead

---
 .../workflow1/ui/BaseScreenViewHolder.kt      |  8 ++--
 .../workflow1/ui/BetterScreenViewHolder.kt    | 46 +++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BetterScreenViewHolder.kt

diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
index c23e553542..51bcb7645b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BaseScreenViewHolder.kt
@@ -3,9 +3,9 @@ package com.squareup.workflow1.ui
 import android.view.View
 
 @WorkflowUiExperimentalApi
-internal class BaseScreenViewHolder<ScreenT: Screen>(
-  private val initialRendering: ScreenT,
-  private val initialViewEnvironment: ViewEnvironment,
+internal class BaseScreenViewHolder<ScreenT : Screen>(
+  initialRendering: ScreenT,
+  initialViewEnvironment: ViewEnvironment,
   override val view: View,
   private val updater: ScreenViewUpdater<ScreenT>
 ) : ScreenViewHolder<ScreenT> {
@@ -18,7 +18,7 @@ internal class BaseScreenViewHolder<ScreenT: Screen>(
     get() = currentEnvironment
 
   override fun start() {
-    showScreen(initialRendering, initialViewEnvironment)
+    showScreen(currentRendering, currentEnvironment)
   }
 
   override fun showScreen(screen: ScreenT, environment: ViewEnvironment) {
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BetterScreenViewHolder.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BetterScreenViewHolder.kt
new file mode 100644
index 0000000000..a75514e9ba
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BetterScreenViewHolder.kt
@@ -0,0 +1,46 @@
+package com.squareup.workflow1.ui
+
+import android.view.View
+
+@WorkflowUiExperimentalApi
+public class BetterScreenViewHolder<ScreenT : Screen> private constructor(
+  public val view: View,
+  private val updater: ScreenViewUpdater<ScreenT>,
+  internal val screenGetter: () -> ScreenT,
+  internal val envGetter: () -> ViewEnvironment,
+  internal val startWrapper: BetterScreenViewHolder<ScreenT>.(() -> Unit) -> Unit,
+) {
+  public constructor(
+    view: View,
+    updater: ScreenViewUpdater<ScreenT>,
+    screen: ScreenT,
+    env: ViewEnvironment
+  ) : this(
+    view = view,
+    updater = updater,
+    screenGetter = { screen },
+    envGetter = { env },
+    startWrapper = { doStart -> doStart() }
+  )
+
+  public val screen: ScreenT get() = screenGetter()
+  public val environment: ViewEnvironment get() = envGetter()
+
+  public fun start() {
+    startWrapper.invoke(this) { updater.showRendering(screen, environment) }
+  }
+
+  public fun canShowScreen(screen: Screen): Boolean = compatible(this.screen, screen)
+
+  public fun withStarter(
+    startWrapper: BetterScreenViewHolder<ScreenT>.(() -> Unit) -> Unit
+  ): BetterScreenViewHolder<ScreenT> {
+    return BetterScreenViewHolder(view, updater, screenGetter, envGetter) { doStart ->
+      startWrapper(doStart)
+    }
+  }
+
+  public fun withShowScreen(
+    
+  )
+}