Introduces AndroidViewRendering, de-emphasizes ViewRegistry

`AndroidViewRendering` is implemented by renderings that can provide their own
`ViewFactory`. `ViewRegistry.buildView` looks to see if a given rendering
implements that method if it fails to find an entry for it -- note that we
look for a registration first, so `ViewRegistry` is able override the default.

Given this, it's no longer crucial for developers to define and provide a
`ViewRegistry`, so we get rid of all the nannying that forced them to provide
one.

Updates the samples to use the new interface and drop their `ViewRegistry`
instances where possible.

Author: rjrjr

samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListLayoutRunner.kt renamed to samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListView.kt

@@ -1,18 +1,3 @@
-/*
- * Copyright 2019 Square Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.squareup.sample.poetryapp
 
 import android.view.LayoutInflater
@@ -25,29 +10,41 @@ import androidx.recyclerview.widget.RecyclerView
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.container.poetryapp.R
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.sample.poetry.model.Poem
+import com.squareup.workflow1.ui.AndroidViewRendering
 import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering> {
+data class PoemListView(
+  val poems: List<Poem>,
+  val onPoemSelected: (Int) -> Unit,
+  val selection: Int = -1
+) : AndroidViewRendering<PoemListView> {
+  override val viewFactory = LayoutRunner.bind(
+    R.layout.list,
+    ::PoemListLayoutRunner
+  )
+}
+
+@OptIn(WorkflowUiExperimentalApi::class)
+private class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListView> {
   init {
     view.findViewById<Toolbar>(R.id.list_toolbar)
-        .apply {
-          title = view.resources.getString(R.string.poems)
-          navigationIcon = null
-        }
+      .apply {
+        title = view.resources.getString(R.string.poems)
+        navigationIcon = null
+      }
   }
 
   private val recyclerView = view.findViewById<RecyclerView>(R.id.list_body)
-      .apply { layoutManager = LinearLayoutManager(context) }
+    .apply { layoutManager = LinearLayoutManager(context) }
 
   private val adapter = Adapter()
 
   override fun showRendering(
-    rendering: PoemListRendering,
+    rendering: PoemListView,
     viewEnvironment: ViewEnvironment
   ) {
     adapter.rendering = rendering
@@ -61,7 +58,7 @@ class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering> {
   private class ViewHolder(val view: TextView) : RecyclerView.ViewHolder(view)
 
   private class Adapter : RecyclerView.Adapter<ViewHolder>() {
-    lateinit var rendering: PoemListRendering
+    lateinit var rendering: PoemListView
     lateinit var environment: ViewEnvironment
 
     override fun onCreateViewHolder(
@@ -76,7 +73,7 @@ class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering> {
       }
 
       return ViewHolder(
-          LayoutInflater.from(parent.context).inflate(layoutId, parent, false) as TextView
+        LayoutInflater.from(parent.context).inflate(layoutId, parent, false) as TextView
       )
     }
 
@@ -95,10 +92,4 @@ class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering> {
       }
     }
   }
-
-  companion object : ViewFactory<PoemListRendering>
-  by bind(
-      R.layout.list,
-      ::PoemListLayoutRunner
-  )
 }

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

@@ -6,21 +6,15 @@ import com.squareup.workflow1.StatelessWorkflow
 /**
  * Renders a given ordered list of [Poem]s. Reports the index of any that are clicked.
  */
-object PoemListWorkflow : StatelessWorkflow<List<Poem>, Int, PoemListRendering>() {
+object PoemListWorkflow : StatelessWorkflow<List<Poem>, Int, PoemListView>() {
 
   override fun render(
     props: List<Poem>,
     context: RenderContext
-  ): PoemListRendering {
-    return PoemListRendering(
+  ): PoemListView {
+    return PoemListView(
         poems = props,
         onPoemSelected = context.eventHandler { index -> setOutput(index) }
     )
   }
 }
-
-data class PoemListRendering(
-  val poems: List<Poem>,
-  val onPoemSelected: (Int) -> Unit,
-  val selection: Int = -1
-)

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

@@ -1,48 +1,31 @@
-/*
- * Copyright 2019 Square Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.squareup.sample.poetryapp
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.sample.container.SampleContainers
-import com.squareup.sample.poetry.PoetryViews
 import com.squareup.sample.poetry.model.Poem
 import com.squareup.workflow1.SimpleLoggingWorkflowInterceptor
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowRunner
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backstack.BackStackContainer
 import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.setContentWorkflow
 import timber.log.Timber
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private val viewRegistry =
-  SampleContainers + PoetryViews + PoemListLayoutRunner + BackStackContainer
+private val viewRegistry = SampleContainers + BackStackContainer
 
 class PoetryActivity : AppCompatActivity() {
   @OptIn(WorkflowUiExperimentalApi::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContentWorkflow(viewRegistry) {
       WorkflowRunner.Config(
-          PoemsBrowserWorkflow,
-          Poem.allPoems,
-          interceptors = listOf(object : SimpleLoggingWorkflowInterceptor() {
-            override fun log(text: String) = Timber.v(text)
-          })
+        PoemsBrowserWorkflow,
+        Poem.allPoems,
+        interceptors = listOf(object : SimpleLoggingWorkflowInterceptor() {
+          override fun log(text: String) = Timber.v(text)
+        })
       )
     }
   }

samples/containers/app-raven/src/main/java/com/squareup/sample/ravenapp/RavenActivity.kt

@@ -1,53 +1,37 @@
-/*
- * Copyright 2019 Square Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.squareup.sample.ravenapp
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.sample.container.SampleContainers
 import com.squareup.sample.poetry.PoemWorkflow
-import com.squareup.sample.poetry.PoetryViews
 import com.squareup.sample.poetry.model.Raven
 import com.squareup.workflow1.SimpleLoggingWorkflowInterceptor
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowRunner
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backstack.BackStackContainer
 import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.setContentWorkflow
 import timber.log.Timber
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private val viewRegistry = SampleContainers + PoetryViews + BackStackContainer
+private val viewRegistry = SampleContainers + BackStackContainer
 
 class RavenActivity : AppCompatActivity() {
   @OptIn(WorkflowUiExperimentalApi::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContentWorkflow(
-        registry = viewRegistry,
-        configure = {
-          WorkflowRunner.Config(
-              PoemWorkflow,
-              Raven,
-              interceptors = listOf(object : SimpleLoggingWorkflowInterceptor() {
-                override fun log(text: String) = Timber.v(text)
-              })
-          )
-        },
-        onResult = { finish() }
+      registry = viewRegistry,
+      configure = {
+        WorkflowRunner.Config(
+          PoemWorkflow,
+          Raven,
+          interceptors = listOf(object : SimpleLoggingWorkflowInterceptor() {
+            override fun log(text: String) = Timber.v(text)
+          })
+        )
+      },
+      onResult = { finish() }
     )
   }
 

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonActivity.kt

@@ -1,34 +1,17 @@
-/*
- * Copyright 2020 Square Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.squareup.sample.hellobackbutton
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.sample.container.SampleContainers
 import com.squareup.workflow1.SimpleLoggingWorkflowInterceptor
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowRunner
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.AlertContainer
 import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.setContentWorkflow
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private val viewRegistry =
-  ViewRegistry(HelloBackButtonLayoutRunner) + SampleContainers + AlertContainer
+private val viewRegistry = SampleContainers + AlertContainer
 
 class HelloBackButtonActivity : AppCompatActivity() {
   @OptIn(WorkflowUiExperimentalApi::class)

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt

@@ -1,46 +1,37 @@
-/*
- * Copyright 2020 Square Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.squareup.sample.hellobackbutton
 
 import android.view.View
 import android.widget.TextView
-import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.Rendering
 import com.squareup.sample.hellobackbutton.R.id
 import com.squareup.sample.hellobackbutton.R.layout
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.AndroidViewRendering
 import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class HelloBackButtonLayoutRunner(view: View) : LayoutRunner<Rendering> {
+data class HelloBackButtonView(
+  val message: String,
+  val onClick: () -> Unit,
+  val onBackPressed: (() -> Unit)?
+) : AndroidViewRendering<HelloBackButtonView> {
+  override val viewFactory: ViewFactory<HelloBackButtonView> = LayoutRunner.bind(
+    layout.hello_back_button_layout, ::HelloBackButtonLayoutRunner
+  )
+}
+
+@OptIn(WorkflowUiExperimentalApi::class)
+private class HelloBackButtonLayoutRunner(view: View) : LayoutRunner<HelloBackButtonView> {
   private val messageView: TextView = view.findViewById(id.hello_message)
 
   override fun showRendering(
-    rendering: Rendering,
+    rendering: HelloBackButtonView,
     viewEnvironment: ViewEnvironment
   ) {
     messageView.text = rendering.message
     messageView.setOnClickListener { rendering.onClick() }
     messageView.backPressedHandler = rendering.onBackPressed
   }
-
-  companion object : ViewFactory<Rendering> by bind(
-      layout.hello_back_button_layout, ::HelloBackButtonLayoutRunner
-  )
 }

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt

@@ -1,7 +1,6 @@
 package com.squareup.sample.hellobackbutton
 
 import android.os.Parcelable
-import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.Rendering
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State.Able
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State.Baker
@@ -12,20 +11,14 @@ import com.squareup.workflow1.ui.toParcelable
 import com.squareup.workflow1.ui.toSnapshot
 import kotlinx.android.parcel.Parcelize
 
-object HelloBackButtonWorkflow : StatefulWorkflow<Unit, State, Nothing, Rendering>() {
+object HelloBackButtonWorkflow : StatefulWorkflow<Unit, State, Nothing, HelloBackButtonView>() {
   @Parcelize
   enum class State : Parcelable {
     Able,
     Baker,
     Charlie;
   }
 
-  data class Rendering(
-    val message: String,
-    val onClick: () -> Unit,
-    val onBackPressed: (() -> Unit)?
-  )
-
   override fun initialState(
     props: Unit,
     snapshot: Snapshot?
@@ -35,8 +28,8 @@ object HelloBackButtonWorkflow : StatefulWorkflow<Unit, State, Nothing, Renderin
     props: Unit,
     state: State,
     context: RenderContext
-  ): Rendering {
-    return Rendering(
+  ): HelloBackButtonView {
+    return HelloBackButtonView(
         message = "$state",
         onClick = context.eventHandler {
           this.state = when (this.state) {