Extracts ScreenViewFactory.map from ScreenViewFactory.forWrapper

Coupling `Wrapper` to `ScreenViewFactory.forWrapper` was a mistake,
made simple transformations that weren't in the strict `Wrapper`
shape more difficult.

Also some compulsive tidying of sample code.

Fixes #973

benchmarks/performance-poetry/complex-poetry/src/main/java/com/squareup/benchmarks/performance/complex/poetry/views/MayBeLoadingScreen.kt

@@ -20,11 +20,3 @@ fun MayBeLoadingScreen(
     loaders.map { FullScreenOverlay(it) }
   )
 }
-
-@OptIn(WorkflowUiExperimentalApi::class)
-val MayBeLoadingScreen.baseScreen: OverviewDetailScreen
-  get() = body.content
-
-@OptIn(WorkflowUiExperimentalApi::class)
-val MayBeLoadingScreen.loaders: List<LoaderSpinner>
-  get() = overlays.map { it.content }

samples/containers/common/src/main/java/com/squareup/sample/container/panel/ScrimScreen.kt

@@ -1,18 +1,17 @@
 package com.squareup.sample.container.panel
 
-import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.Compatible.Companion.keyFor
 import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.Wrapper
 
 /**
  * Show a scrim over some [content], which is invisible if [dimmed] is false,
  * visible if it is true.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class ScrimScreen<T : Screen>(
-  val content: T,
+class ScrimScreen<C : Screen>(
+  override val content: C,
   val dimmed: Boolean
-) : Screen, Compatible {
-  override val compatibilityKey = keyFor(content, "ScrimScreen")
+) : Wrapper<Screen, C>, Screen {
+  override fun <D : Screen> map(transform: (C) -> D) = ScrimScreen(transform(content), dimmed)
 }

samples/containers/hello-back-button/src/androidTest/java/com/squareup/sample/hellobackbutton/HelloBackButtonEspressoTest.kt

@@ -10,7 +10,6 @@ import androidx.test.espresso.matcher.ViewMatchers.withId
 import androidx.test.espresso.matcher.ViewMatchers.withText
 import androidx.test.ext.junit.rules.ActivityScenarioRule
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.internal.test.IdlingDispatcherRule
 import leakcanary.DetectLeaksAfterTestSuccess
 import org.junit.Rule
@@ -19,7 +18,6 @@ import org.junit.rules.RuleChain
 import org.junit.runner.RunWith
 
 @RunWith(AndroidJUnit4::class)
-@OptIn(WorkflowUiExperimentalApi::class)
 class HelloBackButtonEspressoTest {
 
   private val scenarioRule = ActivityScenarioRule(HelloBackButtonActivity::class.java)

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

@@ -2,13 +2,18 @@ package com.squareup.sample.hellobackbutton
 
 import android.os.Parcelable
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.Finished
+import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.Rendering
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State.Quitting
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State.Running
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction.Companion.noAction
 import com.squareup.workflow1.action
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory.Companion.map
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.container.AlertOverlay
 import com.squareup.workflow1.ui.container.AlertOverlay.Button.NEGATIVE
@@ -27,12 +32,21 @@ import kotlinx.parcelize.Parcelize
  */
 @OptIn(WorkflowUiExperimentalApi::class)
 object AreYouSureWorkflow :
-  StatefulWorkflow<Unit, State, Finished, BodyAndOverlaysScreen<*, AlertOverlay>>() {
+  StatefulWorkflow<Unit, State, Finished, Rendering>() {
   override fun initialState(
     props: Unit,
     snapshot: Snapshot?
   ): State = snapshot?.toParcelable() ?: Running
 
+  class Rendering(
+    val base: Screen,
+    val alert: AlertOverlay? = null
+  ) : AndroidScreen<Rendering> {
+    override val viewFactory: ScreenViewFactory<Rendering> = map { newRendering ->
+      BodyAndOverlaysScreen(newRendering.base, listOfNotNull(newRendering.alert))
+    }
+  }
+
   @Parcelize
   enum class State : Parcelable {
     Running,
@@ -45,12 +59,12 @@ object AreYouSureWorkflow :
     renderProps: Unit,
     renderState: State,
     context: RenderContext
-  ): BodyAndOverlaysScreen<*, AlertOverlay> {
+  ): Rendering {
     val ableBakerCharlie = context.renderChild(HelloBackButtonWorkflow, Unit) { noAction() }
 
     return when (renderState) {
       Running -> {
-        BodyAndOverlaysScreen(
+        Rendering(
           BackButtonScreen(ableBakerCharlie) {
             // While we always provide a back button handler, by default the view code
             // associated with BackButtonScreen ignores ours if the view created for the
@@ -80,7 +94,7 @@ object AreYouSureWorkflow :
           }
         )
 
-        BodyAndOverlaysScreen(ableBakerCharlie, alert)
+        Rendering(ableBakerCharlie, alert)
       }
     }
   }

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

@@ -0,0 +1,23 @@
+@file:Suppress("ktlint:filename")
+
+package com.squareup.sample.hellobackbutton
+
+import com.squareup.sample.hellobackbutton.databinding.HelloBackButtonLayoutBinding
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.backPressedHandler
+
+@OptIn(WorkflowUiExperimentalApi::class)
+data class HelloBackButtonScreen(
+  val message: String,
+  val onClick: () -> Unit,
+  val onBackPressed: (() -> Unit)?
+) : AndroidScreen<HelloBackButtonScreen> {
+  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> =
+    ScreenViewFactory.fromViewBinding(HelloBackButtonLayoutBinding::inflate) { rendering, _ ->
+      helloMessage.text = rendering.message
+      helloMessage.setOnClickListener { rendering.onClick() }
+      helloMessage.backPressedHandler = rendering.onBackPressed
+    }
+}

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

@@ -11,12 +11,7 @@ import com.squareup.workflow1.ui.toParcelable
 import com.squareup.workflow1.ui.toSnapshot
 import kotlinx.parcelize.Parcelize
 
-object HelloBackButtonWorkflow : StatefulWorkflow<
-  Unit,
-  State,
-  Nothing,
-  HelloBackButtonScreen
-  >() {
+object HelloBackButtonWorkflow : StatefulWorkflow<Unit, State, Nothing, HelloBackButtonScreen>() {
 
   @Parcelize
   enum class State : Parcelable {

workflow-ui/core-android/api/core-android.api

@@ -129,13 +129,17 @@ public final class com/squareup/workflow1/ui/ScreenViewFactoryKt {
 }
 
 public abstract interface class com/squareup/workflow1/ui/ScreenViewHolder {
+	public static final field Companion Lcom/squareup/workflow1/ui/ScreenViewHolder$Companion;
 	public abstract fun getEnvironment ()Lcom/squareup/workflow1/ui/ViewEnvironment;
 	public abstract fun getRunner ()Lcom/squareup/workflow1/ui/ScreenViewRunner;
 	public abstract fun getView ()Landroid/view/View;
 }
 
+public final class com/squareup/workflow1/ui/ScreenViewHolder$Companion {
+	public final fun invoke (Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/view/View;Lcom/squareup/workflow1/ui/ScreenViewRunner;)Lcom/squareup/workflow1/ui/ScreenViewHolder;
+}
+
 public final class com/squareup/workflow1/ui/ScreenViewHolderKt {
-	public static final fun ScreenViewHolder (Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/view/View;Lcom/squareup/workflow1/ui/ScreenViewRunner;)Lcom/squareup/workflow1/ui/ScreenViewHolder;
 	public static final fun canShow (Lcom/squareup/workflow1/ui/ScreenViewHolder;Lcom/squareup/workflow1/ui/Screen;)Z
 	public static final fun getShowing (Lcom/squareup/workflow1/ui/ScreenViewHolder;)Lcom/squareup/workflow1/ui/Screen;
 	public static final fun show (Lcom/squareup/workflow1/ui/ScreenViewHolder;Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
@@ -429,16 +433,20 @@ public final class com/squareup/workflow1/ui/container/OverlayDialogFactoryKt {
 }
 
 public abstract interface class com/squareup/workflow1/ui/container/OverlayDialogHolder {
+	public static final field Companion Lcom/squareup/workflow1/ui/container/OverlayDialogHolder$Companion;
 	public abstract fun getDialog ()Landroid/app/Dialog;
 	public abstract fun getEnvironment ()Lcom/squareup/workflow1/ui/ViewEnvironment;
 	public abstract fun getOnBackPressed ()Lkotlin/jvm/functions/Function0;
 	public abstract fun getOnUpdateBounds ()Lkotlin/jvm/functions/Function1;
 	public abstract fun getRunner ()Lkotlin/jvm/functions/Function2;
 }
 
+public final class com/squareup/workflow1/ui/container/OverlayDialogHolder$Companion {
+	public final fun invoke (Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/app/Dialog;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;Lkotlin/jvm/functions/Function2;)Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;
+	public static synthetic fun invoke$default (Lcom/squareup/workflow1/ui/container/OverlayDialogHolder$Companion;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/app/Dialog;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;
+}
+
 public final class com/squareup/workflow1/ui/container/OverlayDialogHolderKt {
-	public static final fun OverlayDialogHolder (Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/app/Dialog;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;Lkotlin/jvm/functions/Function2;)Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;
-	public static synthetic fun OverlayDialogHolder$default (Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/app/Dialog;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;
 	public static final fun canShow (Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;Lcom/squareup/workflow1/ui/container/Overlay;)Z
 	public static final fun getShowing (Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;)Lcom/squareup/workflow1/ui/container/Overlay;
 	public static final fun show (Lcom/squareup/workflow1/ui/container/OverlayDialogHolder;Lcom/squareup/workflow1/ui/container/Overlay;Lcom/squareup/workflow1/ui/ViewEnvironment;)V