wip: Replaces View.showRendering et al with a wrapper interface

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 { initialRendering, initialViewEnvironment, context, container ->
+    initialRendering.wrapped
+      // Build the view for the wrapped rendering.
+      .buildView(initialViewEnvironment, context, container)
+      // Transform it to accept BackButtonScreen directly
+      .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 ->
+        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
+        }
+      }
   }
-)

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
+          }
+        }
+    }
   )
 }

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)
@@ -60,14 +60,14 @@ class OverviewDetailContainer(view: View) : ScreenViewRunner<OverviewDetailScree
       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
         }
     }
   }
@@ -84,11 +84,9 @@ class OverviewDetailContainer(view: View) : ScreenViewRunner<OverviewDetailScree
     stub.show(combined, viewEnvironment + (OverviewDetailConfig to Single))
   }
 
-  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewRunner.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"
-    private const val DetailBackStackKey = "detail"
   }
 }

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 buildDialogWithContentView(contentView: View): Dialog {
-    val context = contentView.context
+  override fun buildDialogWithContent(content: ScreenViewHolder<*>): Dialog {
+    val context = content.view.context
     return Dialog(context, R.style.PanelDialog).also { dialog ->
-      dialog.setContentView(contentView)
+      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.

samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt

@@ -12,7 +12,8 @@ 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.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewUpdater
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
@@ -22,14 +23,13 @@ data class PoemListScreen(
   val onPoemSelected: (Int) -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<PoemListScreen> {
-  override val viewFactory = ScreenViewRunner.bind(
-    R.layout.list,
-    ::PoemListLayoutRunner
-  )
+  override val viewFactory = ScreenViewFactory.ofLayout(
+    R.layout.list
+  ) { it: View -> PoemListLayoutUpdater(it) }
 }
 
 @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 {

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt → 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> = ScreenViewFactory.ofLayout(
+    R.layout.hello_back_button_layout
+  ) { it: View -> HelloBackButtonLayoutUpdater(it) }
 }
 
 @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(

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 +28,13 @@ data class StanzaListScreen(
   val onExit: () -> Unit,
   val selection: Int = -1
 ) : AndroidScreen<StanzaListScreen> {
-  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewRunner.bind(
-    R.layout.list,
-    ::StanzaListLayoutRunner
-  )
+  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewFactory.ofLayout(
+    R.layout.list
+  ) { it: View -> StanzaListLayoutUpdater(it) }
 }
 
 @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) }

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 +32,13 @@ data class StanzaScreen(
 ) : AndroidScreen<StanzaScreen>, Compatible {
   override val compatibilityKey = "$title: $stanzaNumber"
 
-  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewRunner.bind(
-    R.layout.stanza_layout,
-    ::StanzaLayoutRunner
-  )
+  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewFactory.ofLayout(
+    R.layout.stanza_layout
+  ) { it: View -> StanzaLayoutUpdater(it) }
 }
 
 @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 +113,7 @@ private class StanzaLayoutRunner(private val view: View) : ScreenViewRunner<Stan
     setText(spans, SPANNABLE)
   }
 
-  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewRunner.bind(
-      R.layout.stanza_layout,
-      ::StanzaLayoutRunner
+  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewFactory.ofLayout(R.layout.stanza_layout,
+    { it: View -> StanzaLayoutUpdater(it) }
   )
 }

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) }
+        }
     })
 }