Host-side API for view-owned widgets (#2458)

* Host-side API for view-owned widgets

This introduces a new mutable property, windowInsets, that is propagated to the composition where it can be consumed.

We put the burden on the user of RedwoodView to set this value to something non-zero if they have insets to be consumed. I've added an accelerator on Android for this,

RedwoodLayout.consumeWindowInsets(mask: Int)

* Spotless

redwood-runtime/api/android/redwood-runtime.api

@@ -245,13 +245,16 @@ public final class app/cash/redwood/ui/UiConfiguration {
 	public static final field $stable I
 	public static final field Companion Lapp/cash/redwood/ui/UiConfiguration$Companion;
 	public fun <init> ()V
-	public fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)V
-	public synthetic fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)V
+	public synthetic fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun copy (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)Lapp/cash/redwood/ui/UiConfiguration;
+	public static synthetic fun copy$default (Lapp/cash/redwood/ui/UiConfiguration;ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILjava/lang/Object;)Lapp/cash/redwood/ui/UiConfiguration;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getDarkMode ()Z
 	public final fun getDensity ()D
 	public final fun getLayoutDirection ()Lapp/cash/redwood/ui/LayoutDirection;
 	public final fun getSafeAreaInsets ()Lapp/cash/redwood/ui/Margin;
+	public final fun getViewInsets ()Lapp/cash/redwood/ui/Margin;
 	public final fun getViewportSize ()Lapp/cash/redwood/ui/Size;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;

redwood-runtime/api/jvm/redwood-runtime.api

@@ -241,13 +241,16 @@ public final class app/cash/redwood/ui/UiConfiguration {
 	public static final field $stable I
 	public static final field Companion Lapp/cash/redwood/ui/UiConfiguration$Companion;
 	public fun <init> ()V
-	public fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)V
-	public synthetic fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)V
+	public synthetic fun <init> (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun copy (ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;)Lapp/cash/redwood/ui/UiConfiguration;
+	public static synthetic fun copy$default (Lapp/cash/redwood/ui/UiConfiguration;ZLapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Margin;Lapp/cash/redwood/ui/Size;DLapp/cash/redwood/ui/LayoutDirection;ILjava/lang/Object;)Lapp/cash/redwood/ui/UiConfiguration;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getDarkMode ()Z
 	public final fun getDensity ()D
 	public final fun getLayoutDirection ()Lapp/cash/redwood/ui/LayoutDirection;
 	public final fun getSafeAreaInsets ()Lapp/cash/redwood/ui/Margin;
+	public final fun getViewInsets ()Lapp/cash/redwood/ui/Margin;
 	public final fun getViewportSize ()Lapp/cash/redwood/ui/Size;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;

redwood-runtime/api/redwood-runtime.klib.api

@@ -142,7 +142,7 @@ final class app.cash.redwood.ui/Size { // app.cash.redwood.ui/Size|null[0]
 }
 
 final class app.cash.redwood.ui/UiConfiguration { // app.cash.redwood.ui/UiConfiguration|null[0]
-    constructor <init>(kotlin/Boolean = ..., app.cash.redwood.ui/Margin = ..., app.cash.redwood.ui/Size? = ..., kotlin/Double = ..., app.cash.redwood.ui/LayoutDirection = ...) // app.cash.redwood.ui/UiConfiguration.<init>|<init>(kotlin.Boolean;app.cash.redwood.ui.Margin;app.cash.redwood.ui.Size?;kotlin.Double;app.cash.redwood.ui.LayoutDirection){}[0]
+    constructor <init>(kotlin/Boolean = ..., app.cash.redwood.ui/Margin = ..., app.cash.redwood.ui/Margin = ..., app.cash.redwood.ui/Size? = ..., kotlin/Double = ..., app.cash.redwood.ui/LayoutDirection = ...) // app.cash.redwood.ui/UiConfiguration.<init>|<init>(kotlin.Boolean;app.cash.redwood.ui.Margin;app.cash.redwood.ui.Margin;app.cash.redwood.ui.Size?;kotlin.Double;app.cash.redwood.ui.LayoutDirection){}[0]
 
     final val darkMode // app.cash.redwood.ui/UiConfiguration.darkMode|{}darkMode[0]
         final fun <get-darkMode>(): kotlin/Boolean // app.cash.redwood.ui/UiConfiguration.darkMode.<get-darkMode>|<get-darkMode>(){}[0]
@@ -152,9 +152,12 @@ final class app.cash.redwood.ui/UiConfiguration { // app.cash.redwood.ui/UiConfi
         final fun <get-layoutDirection>(): app.cash.redwood.ui/LayoutDirection // app.cash.redwood.ui/UiConfiguration.layoutDirection.<get-layoutDirection>|<get-layoutDirection>(){}[0]
     final val safeAreaInsets // app.cash.redwood.ui/UiConfiguration.safeAreaInsets|{}safeAreaInsets[0]
         final fun <get-safeAreaInsets>(): app.cash.redwood.ui/Margin // app.cash.redwood.ui/UiConfiguration.safeAreaInsets.<get-safeAreaInsets>|<get-safeAreaInsets>(){}[0]
+    final val viewInsets // app.cash.redwood.ui/UiConfiguration.viewInsets|{}viewInsets[0]
+        final fun <get-viewInsets>(): app.cash.redwood.ui/Margin // app.cash.redwood.ui/UiConfiguration.viewInsets.<get-viewInsets>|<get-viewInsets>(){}[0]
     final val viewportSize // app.cash.redwood.ui/UiConfiguration.viewportSize|{}viewportSize[0]
         final fun <get-viewportSize>(): app.cash.redwood.ui/Size? // app.cash.redwood.ui/UiConfiguration.viewportSize.<get-viewportSize>|<get-viewportSize>(){}[0]
 
+    final fun copy(kotlin/Boolean = ..., app.cash.redwood.ui/Margin = ..., app.cash.redwood.ui/Margin = ..., app.cash.redwood.ui/Size? = ..., kotlin/Double = ..., app.cash.redwood.ui/LayoutDirection = ...): app.cash.redwood.ui/UiConfiguration // app.cash.redwood.ui/UiConfiguration.copy|copy(kotlin.Boolean;app.cash.redwood.ui.Margin;app.cash.redwood.ui.Margin;app.cash.redwood.ui.Size?;kotlin.Double;app.cash.redwood.ui.LayoutDirection){}[0]
     final fun equals(kotlin/Any?): kotlin/Boolean // app.cash.redwood.ui/UiConfiguration.equals|equals(kotlin.Any?){}[0]
     final fun hashCode(): kotlin/Int // app.cash.redwood.ui/UiConfiguration.hashCode|hashCode(){}[0]
     final fun toString(): kotlin/String // app.cash.redwood.ui/UiConfiguration.toString|toString(){}[0]

redwood-runtime/src/commonMain/kotlin/app/cash/redwood/ui/UiConfiguration.kt

@@ -25,13 +25,23 @@ public class UiConfiguration(
    * True if the device is configured to use a dark color palette.
    */
   public val darkMode: Boolean = false,
+
   /**
-   * A set of distances from the edges of the display where system UI and other elements will be
-   * drawn.
-   *
-   * Use this margin to inset your content to avoid drawing under system UI elements.
+   * The insets of the host window, independent of where the Redwood composition is positioned
+   * within it. The Redwood composition is not responsible for consuming these insets.
    */
   public val safeAreaInsets: Margin = Margin.Zero,
+
+  /**
+   * The insets of the viewport that the composition is responsible for consuming.
+   *
+   * This may be zero if the host view isn't attached to a view hierarchy and therefore doesn't
+   * know its insets.
+   *
+   * See https://developer.android.com/develop/ui/views/layout/edge-to-edge
+   */
+  public val viewInsets: Margin = Margin.Zero,
+
   /**
    * The size of the viewport into which the composition is rendering. This could be as lage as the
    * entire screen or as small as an individual view within a larger native screen.
@@ -55,5 +65,21 @@ public class UiConfiguration(
    */
   public val layoutDirection: LayoutDirection = LayoutDirection.Ltr,
 ) {
+  public fun copy(
+    darkMode: Boolean = this.darkMode,
+    safeAreaInsets: Margin = this.safeAreaInsets,
+    viewInsets: Margin = this.viewInsets,
+    viewportSize: Size? = this.viewportSize,
+    density: Double = this.density,
+    layoutDirection: LayoutDirection = this.layoutDirection,
+  ): UiConfiguration = UiConfiguration(
+    darkMode = darkMode,
+    safeAreaInsets = safeAreaInsets,
+    viewInsets = viewInsets,
+    viewportSize = viewportSize,
+    density = density,
+    layoutDirection = layoutDirection,
+  )
+
   public companion object
 }

redwood-treehouse-host-composeui/src/commonMain/kotlin/app/cash/redwood/treehouse/composeui/TreehouseContent.kt

@@ -41,6 +41,7 @@ import app.cash.redwood.treehouse.TreehouseView.WidgetSystem
 import app.cash.redwood.treehouse.bindWhenReady
 import app.cash.redwood.ui.Density
 import app.cash.redwood.ui.LayoutDirection as RedwoodLayoutDirection
+import app.cash.redwood.ui.Margin
 import app.cash.redwood.ui.OnBackPressedDispatcher
 import app.cash.redwood.ui.Size
 import app.cash.redwood.ui.UiConfiguration
@@ -65,6 +66,7 @@ public fun <A : AppService> TreehouseContent(
   val uiConfiguration = UiConfiguration(
     darkMode = isSystemInDarkTheme(),
     safeAreaInsets = safeAreaInsets(),
+    viewInsets = Margin.Zero,
     viewportSize = viewportSize,
     density = density.density.toDouble(),
     layoutDirection = when (LocalLayoutDirection.current) {

redwood-treehouse-host/src/androidUnitTest/kotlin/app/cash/redwood/treehouse/TreehouseLayoutTest.kt

@@ -98,7 +98,10 @@ class TreehouseLayoutTest {
   @Test fun uiConfigurationEmitsSystemBarsSafeAreaInsetsChanges() = runTest {
     val layout = TreehouseLayout(activity, throwingWidgetSystem, activity.onBackPressedDispatcher)
     layout.uiConfiguration.test {
-      assertThat(awaitItem().safeAreaInsets).isEqualTo(Margin.Zero)
+      val value1 = awaitItem()
+      assertThat(value1.safeAreaInsets).isEqualTo(Margin.Zero)
+      assertThat(value1.viewInsets).isEqualTo(Margin.Zero)
+
       val insets = Insets.of(10, 20, 30, 40)
       val windowInsets = WindowInsetsCompat.Builder()
         .setInsets(WindowInsetsCompat.Type.systemBars(), insets)
@@ -112,7 +115,9 @@ class TreehouseLayoutTest {
           bottom = insets.bottom.toDp(),
         )
       }
-      assertThat(awaitItem().safeAreaInsets).isEqualTo(expectedInsets)
+      val value2 = awaitItem()
+      assertThat(value2.safeAreaInsets).isEqualTo(Margin.Zero)
+      assertThat(value2.viewInsets).isEqualTo(expectedInsets)
     }
   }
 

redwood-widget/src/androidMain/kotlin/app/cash/redwood/widget/RedwoodLayout.kt

@@ -22,12 +22,12 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.activity.OnBackPressedCallback as AndroidOnBackPressedCallback
 import androidx.activity.OnBackPressedDispatcher as AndroidOnBackPressedDispatcher
-import androidx.core.graphics.Insets
 import androidx.core.view.children as viewGroupChildren
 import androidx.savedstate.findViewTreeSavedStateRegistryOwner
 import app.cash.redwood.ui.Cancellable
 import app.cash.redwood.ui.Density
 import app.cash.redwood.ui.LayoutDirection
+import app.cash.redwood.ui.Margin
 import app.cash.redwood.ui.OnBackPressedCallback as RedwoodOnBackPressedCallback
 import app.cash.redwood.ui.OnBackPressedDispatcher as RedwoodOnBackPressedDispatcher
 import app.cash.redwood.ui.Size
@@ -51,7 +51,11 @@ public open class RedwoodLayout(
     id = R.id.redwood_layout
   }
 
-  private val mutableUiConfiguration = MutableStateFlow(computeUiConfiguration())
+  private val mutableUiConfiguration = MutableStateFlow(
+    computeUiConfiguration(
+      viewInsets = Margin.Zero,
+    ),
+  )
 
   override val onBackPressedDispatcher: RedwoodOnBackPressedDispatcher =
     object : RedwoodOnBackPressedDispatcher {
@@ -82,7 +86,9 @@ public open class RedwoodLayout(
 
   init {
     setOnWindowInsetsChangeListener { insets ->
-      mutableUiConfiguration.value = computeUiConfiguration(insets = insets.safeDrawing)
+      mutableUiConfiguration.value = computeUiConfiguration(
+        viewInsets = insets.safeDrawing.toMargin(Density(resources)),
+      )
     }
   }
 
@@ -112,7 +118,7 @@ public open class RedwoodLayout(
 
   private fun computeUiConfiguration(
     config: Configuration = context.resources.configuration,
-    insets: Insets = rootWindowInsetsCompat.safeDrawing,
+    viewInsets: Margin = uiConfiguration.value.viewInsets,
   ): UiConfiguration {
     val viewportSize: Size
     val density: Double
@@ -122,7 +128,8 @@ public open class RedwoodLayout(
     }
     return UiConfiguration(
       darkMode = (config.uiMode and Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES,
-      safeAreaInsets = insets.toMargin(Density(resources)),
+      safeAreaInsets = Margin.Zero,
+      viewInsets = viewInsets,
       viewportSize = viewportSize,
       density = density,
       layoutDirection = when (config.layoutDirection) {

redwood-widget/src/iosMain/kotlin/app/cash/redwood/widget/RedwoodUIView.kt

@@ -58,6 +58,7 @@ public open class RedwoodUIView : RedwoodView<UIView> {
     MutableStateFlow(
       computeUiConfiguration(
         traitCollection = valueRootView.traitCollection,
+        viewInsets = Margin.Zero,
         layoutDirection = valueRootView.effectiveUserInterfaceLayoutDirection,
         bounds = valueRootView.bounds,
       ),
@@ -78,8 +79,10 @@ public open class RedwoodUIView : RedwoodView<UIView> {
     get() = null
 
   private fun updateUiConfiguration() {
+    val old = mutableUiConfiguration.value
     mutableUiConfiguration.value = computeUiConfiguration(
       traitCollection = valueRootView.traitCollection,
+      viewInsets = old.viewInsets,
       layoutDirection = valueRootView.effectiveUserInterfaceLayoutDirection,
       bounds = valueRootView.bounds,
     )
@@ -124,12 +127,14 @@ public open class RedwoodUIView : RedwoodView<UIView> {
 
 internal fun computeUiConfiguration(
   traitCollection: UITraitCollection,
+  viewInsets: Margin,
   layoutDirection: UIUserInterfaceLayoutDirection,
   bounds: CValue<CGRect>,
 ): UiConfiguration {
   return UiConfiguration(
     darkMode = traitCollection.userInterfaceStyle == UIUserInterfaceStyle.UIUserInterfaceStyleDark,
     safeAreaInsets = computeSafeAreaInsets(),
+    viewInsets = viewInsets,
     viewportSize = bounds.useContents {
       with(Density.Default) {
         Size(size.width.toDp(), size.height.toDp())

redwood-widget/src/jsMain/kotlin/app/cash/redwood/widget/RedwoodHTMLElementView.kt

@@ -17,6 +17,7 @@ package app.cash.redwood.widget
 
 import app.cash.redwood.ui.Cancellable
 import app.cash.redwood.ui.LayoutDirection
+import app.cash.redwood.ui.Margin
 import app.cash.redwood.ui.OnBackPressedCallback
 import app.cash.redwood.ui.OnBackPressedDispatcher
 import app.cash.redwood.ui.Size
@@ -64,6 +65,7 @@ private class RedwoodHTMLElementView(
     _uiConfiguration = MutableStateFlow(
       UiConfiguration(
         darkMode = colorSchemeQuery.matches,
+        viewInsets = Margin.Zero,
         viewportSize = Size(width = value.offsetWidth.dp, height = value.offsetHeight.dp),
         layoutDirection = when (value.dir) {
           "ltr" -> LayoutDirection.Ltr
@@ -75,15 +77,7 @@ private class RedwoodHTMLElementView(
     )
 
     colorSchemeQuery.addEventListener("change", { event ->
-      updateUiConfiguration { old ->
-        UiConfiguration(
-          darkMode = event.unsafeCast<MediaQueryList>().matches,
-          safeAreaInsets = old.safeAreaInsets,
-          viewportSize = old.viewportSize,
-          density = old.density,
-          layoutDirection = old.layoutDirection,
-        )
-      }
+      updateUiConfiguration { it.copy(darkMode = event.unsafeCast<MediaQueryList>().matches) }
     })
 
     observePixelRatioChange()
@@ -107,15 +101,7 @@ private class RedwoodHTMLElementView(
       pixelRatioQuery.removeEventListener("change", listener)
     }
 
-    updateUiConfiguration { old ->
-      UiConfiguration(
-        darkMode = old.darkMode,
-        safeAreaInsets = old.safeAreaInsets,
-        viewportSize = old.viewportSize,
-        density = window.devicePixelRatio,
-        layoutDirection = old.layoutDirection,
-      )
-    }
+    updateUiConfiguration { it.copy(density = window.devicePixelRatio) }
   }
 
   private fun updateUiConfiguration(updater: (UiConfiguration) -> UiConfiguration) {