Refactor ComposeScene (#908)

## Proposed Changes

It's the evolution of #891

Compose scene:
- Deprecate the existing API and introduce an internal interface instead
- Remove key listeners from `setContent`
- `constraints` -> `size`
- Add `lastKnownPointerPosition` to public interface 
- `CombinedComposeScene` as a compatible version of scene
- Remove recently added `semanticsOwner`
- `ComposeScene.Pointer` -> `ComposeScenePointer`

Other changes:
- Rename `SkiaBasedOwner` to `RootNodeOwner`. Also, it uses aggregation
instead of implementing a few interfaces.
- `SkikoComposeUiTest` overrides `PlatformContext.RootForTestListener`
now. It solves TODOs about `WindowInfo` in tests.
- `SkiaRootForTest` is renamed to `PlatformRootForTest`
- `onRootCreatedCallback`/`onRootDisposedCallback` is now part of
`PlatformContext`
- `PlatformRootForTest` exposes real `visibleBounds` instead of just
window size information.
- `PlatformRootForTest` exposes send pointer input methods instead of
`scene` reference.
- `InternalComposeUiApi` is opted in inside the same module.
- `Platform` -> `PlatfromContext`
- `dialogScrimBlendMode` -> `isWindowTransparent`
- `AccessibilityController`: Remove interface from `skikoMain` source
set
- `AccessibilityController`: `syncLoop` triggered right from
desktop-only part
- Replaced `Platform.accessibilityController(SemanticsOwner)` to
`semanticsOwnerListener`
- Fixes an invalid test case: out of screen Popup cannot receive input
now
- Removed unnecessary expect/actual `createSkiaLayer`
- Moves "Deprecated" `DefaultViewConfiguration` to test where there is a
single usage of it.

## API Changes

See `compose/ui/ui/api/desktop/ui.api` file

## Testing

Test: run existing tests.

compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/ScrollbarTest.kt

@@ -53,6 +53,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.ExperimentalComposeUiApi
+import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
@@ -1216,7 +1217,7 @@ class ScrollbarTest {
     }
 
 
-    @OptIn(InternalTestApi::class)
+    @OptIn(InternalTestApi::class, InternalComposeUiApi::class)
     private fun ComposeTestRule.performMouseScroll(x: Int, y: Int, delta: Float) {
         (this as DesktopComposeTestRule).scene.sendPointerEvent(
             PointerEventType.Scroll,

compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/gestures/DesktopScrollableTest.kt

@@ -27,6 +27,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
@@ -49,6 +50,7 @@ import org.junit.Test
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 
+@OptIn(InternalComposeUiApi::class)
 @ExperimentalTestApi
 @RunWith(JUnit4::class)
 class DesktopScrollableTest {

compose/foundation/foundation/src/skikoTest/kotlin/androidx/compose/foundation/OnClickTest.kt

@@ -22,6 +22,7 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.size
 import androidx.compose.ui.ComposeScene
 import androidx.compose.ui.ImageComposeScene
+import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.pointer.PointerButton
@@ -43,7 +44,7 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.runTest
 
 @ExperimentalCoroutinesApi
-@OptIn(ExperimentalFoundationApi::class)
+@OptIn(ExperimentalFoundationApi::class, InternalComposeUiApi::class)
 class OnClickTest {
 
     private fun testClick(

compose/foundation/foundation/src/skikoTest/kotlin/androidx/compose/foundation/gestures/DragGestureTest.kt

@@ -21,13 +21,15 @@ import androidx.compose.foundation.PointerMatcher
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.size
 import androidx.compose.ui.ImageComposeScene
+import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.pointer.PointerButton
 import androidx.compose.ui.input.pointer.PointerButtons
 import androidx.compose.ui.input.pointer.PointerEventType
 import androidx.compose.ui.input.pointer.PointerType
-import androidx.compose.ui.platform.DefaultViewConfiguration
+import androidx.compose.ui.platform.PlatformContext
+import androidx.compose.ui.platform.ViewConfiguration
 import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.use
@@ -38,7 +40,6 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.test.UnconfinedTestDispatcher
 import kotlinx.coroutines.test.runTest
 
-@Suppress("DEPRECATION")
 @OptIn(ExperimentalFoundationApi::class)
 class DragGestureTest {
 
@@ -462,3 +463,9 @@ class DragGestureTest {
         }
     }
 }
+
+@OptIn(InternalComposeUiApi::class)
+private class DefaultViewConfiguration(private val density: Density) : ViewConfiguration by PlatformContext.Empty.viewConfiguration {
+    override val touchSlop: Float
+        get() = with(density) { PlatformContext.Empty.viewConfiguration.touchSlop.dp.toPx() }
+}

compose/ui/ui-test-junit4/src/desktopMain/kotlin/androidx/compose/ui/test/junit4/DesktopComposeTestRule.desktop.kt

@@ -17,7 +17,8 @@
 package androidx.compose.ui.test.junit4
 
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.ComposeScene
+import androidx.compose.ui.InternalComposeUiApi
+import androidx.compose.ui.scene.ComposeScene
 import androidx.compose.ui.test.DesktopComposeUiTest
 import androidx.compose.ui.test.ExperimentalTestApi
 import androidx.compose.ui.test.IdlingResource
@@ -57,6 +58,7 @@ class DesktopComposeTestRule private constructor(
         effectContext: CoroutineContext = EmptyCoroutineContext
     ) : this(DesktopComposeUiTest(effectContext = effectContext))
 
+    @InternalComposeUiApi
     var scene: ComposeScene
         get() = composeTest.scene
         set(value) {

compose/ui/ui-test-junit4/src/skikoMain/kotlin/androidx/compose/ui/test/ComposeUiTest.skikoMain.kt

@@ -17,18 +17,20 @@
 package androidx.compose.ui.test
 
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.snapshots.Snapshot
-import androidx.compose.ui.ComposeScene
 import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asComposeCanvas
 import androidx.compose.ui.graphics.toComposeImageBitmap
 import androidx.compose.ui.node.RootForTest
 import androidx.compose.ui.platform.InfiniteAnimationPolicy
-import androidx.compose.ui.platform.LocalWindowInfo
+import androidx.compose.ui.platform.PlatformContext
 import androidx.compose.ui.platform.WindowInfo
+import androidx.compose.ui.scene.MultiLayerComposeScene
+import androidx.compose.ui.scene.ComposeScene
+import androidx.compose.ui.scene.ComposeSceneContext
 import androidx.compose.ui.semantics.SemanticsNode
 import androidx.compose.ui.test.junit4.ComposeRootRegistry
 import androidx.compose.ui.test.junit4.MainTestClockImpl
@@ -41,7 +43,6 @@ import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.ImeOptions
 import androidx.compose.ui.text.input.PlatformTextInputService
 import androidx.compose.ui.text.input.TextFieldValue
-import androidx.compose.ui.unit.Constraints
 import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.IntSize
 import kotlin.coroutines.CoroutineContext
@@ -90,7 +91,7 @@ private const val IDLING_RESOURCES_CHECK_INTERVAL_MS = 20L
  * `LaunchedEffect`s and `rememberCoroutineScope` will be derived from this context.
  */
 @ExperimentalTestApi
-@OptIn(ExperimentalCoroutinesApi::class, InternalTestApi::class)
+@OptIn(ExperimentalCoroutinesApi::class, InternalTestApi::class, InternalComposeUiApi::class)
 class SkikoComposeUiTest(
     width: Int = 1024,
     height: Int = 768,
@@ -111,31 +112,6 @@ class SkikoComposeUiTest(
         var onImeActionPerformed: (ImeAction) -> Unit,
     )
 
-    private val textInputService = object : PlatformTextInputService {
-        var session: Session? = null
-
-        override fun startInput(
-            value: TextFieldValue,
-            imeOptions: ImeOptions,
-            onEditCommand: (List<EditCommand>) -> Unit,
-            onImeActionPerformed: (ImeAction) -> Unit
-        ) {
-            session = Session(
-                imeOptions = imeOptions,
-                onEditCommand = onEditCommand,
-                onImeActionPerformed = onImeActionPerformed
-            )
-        }
-
-        override fun stopInput() {
-            session = null
-        }
-
-        override fun showSoftwareKeyboard() = Unit
-        override fun hideSoftwareKeyboard() = Unit
-        override fun updateState(oldValue: TextFieldValue?, newValue: TextFieldValue) = Unit
-    }
-
     private val composeRootRegistry = ComposeRootRegistry()
 
     private val coroutineDispatcher = UnconfinedTestDispatcher()
@@ -157,7 +133,9 @@ class SkikoComposeUiTest(
     private val coroutineContext =
         coroutineDispatcher + uncaughtExceptionHandler + infiniteAnimationPolicy
     private val surface = Surface.makeRasterN32Premul(width, height)
+    private val size = IntSize(width, height)
 
+    @InternalComposeUiApi
     lateinit var scene: ComposeScene
         internal set
 
@@ -188,7 +166,7 @@ class SkikoComposeUiTest(
 
     private fun render(timeMillis: Long) {
         scene.render(
-            surface.canvas,
+            surface.canvas.asComposeCanvas(),
             timeMillis * NanoSecondsPerMilliSecond
         )
     }
@@ -200,14 +178,13 @@ class SkikoComposeUiTest(
         }
     }
 
-    private fun createUi() = ComposeScene(
-        textInputService = textInputService,
+    private fun createUi() = MultiLayerComposeScene(
         density = density,
         coroutineContext = coroutineContext,
+        composeSceneContext = TestComposeSceneContext(),
         invalidate = { }
-    ).apply {
-        constraints = Constraints(maxWidth = surface.width, maxHeight = surface.height)
-        // TODO: Initialize WindowInfo once public way is available
+    ).also {
+        it.size = size
     }
 
     private fun shouldPumpTime(): Boolean {
@@ -303,22 +280,11 @@ class SkikoComposeUiTest(
 
     @OptIn(ExperimentalComposeUiApi::class)
     override fun setContent(composable: @Composable () -> Unit) {
-        // TODO: Remove override once it's properly initialized
-        val overriddenComposable: @Composable () -> Unit = {
-            val windowInfo = object : WindowInfo by LocalWindowInfo.current {
-                override val containerSize: IntSize
-                    get() = IntSize(surface.width, surface.height)
-            }
-            CompositionLocalProvider(
-                LocalWindowInfo provides windowInfo,
-                content = composable
-            )
-        }
         if (isOnUiThread()) {
-            scene.setContent(content = overriddenComposable)
+            scene.setContent(content = composable)
         } else {
             runOnUiThread {
-                scene.setContent(content = overriddenComposable)
+                scene.setContent(content = composable)
             }
 
             // Only wait for idleness if not on the UI thread. If we are on the UI thread, the
@@ -375,6 +341,54 @@ class SkikoComposeUiTest(
         override fun captureToImage(semanticsNode: SemanticsNode): ImageBitmap =
             this@SkikoComposeUiTest.captureToImage(semanticsNode)
     }
+
+    private inner class TestWindowInfo : WindowInfo {
+        override val isWindowFocused: Boolean
+            get() = true
+
+        @ExperimentalComposeUiApi
+        override val containerSize: IntSize
+            get() = size
+    }
+
+    private inner class TestTextInputService : PlatformTextInputService {
+        var session: Session? = null
+
+        override fun startInput(
+            value: TextFieldValue,
+            imeOptions: ImeOptions,
+            onEditCommand: (List<EditCommand>) -> Unit,
+            onImeActionPerformed: (ImeAction) -> Unit
+        ) {
+            session = Session(
+                imeOptions = imeOptions,
+                onEditCommand = onEditCommand,
+                onImeActionPerformed = onImeActionPerformed
+            )
+        }
+
+        override fun stopInput() {
+            session = null
+        }
+
+        override fun showSoftwareKeyboard() = Unit
+        override fun hideSoftwareKeyboard() = Unit
+        override fun updateState(oldValue: TextFieldValue?, newValue: TextFieldValue) = Unit
+    }
+
+    private inner class TestContext : PlatformContext by PlatformContext.Empty {
+        override val windowInfo: WindowInfo =
+            TestWindowInfo()
+        override val textInputService: PlatformTextInputService =
+            TestTextInputService()
+
+        override val rootForTestListener: PlatformContext.RootForTestListener?
+            get() = composeRootRegistry
+    }
+
+    private inner class TestComposeSceneContext : ComposeSceneContext {
+        override val platformContext = TestContext()
+    }
 }
 
 @ExperimentalTestApi

compose/ui/ui-test-junit4/src/skikoMain/kotlin/androidx/compose/ui/test/junit4/ComposeRootRegistry.skiko.kt

@@ -17,65 +17,63 @@
 package androidx.compose.ui.test.junit4
 
 import androidx.compose.ui.InternalComposeUiApi
-import androidx.compose.ui.platform.SkiaRootForTest
+import androidx.compose.ui.platform.PlatformContext
+import androidx.compose.ui.platform.PlatformRootForTest
 
 /**
- * Registry where all views implementing [SkiaRootForTest] should be registered while they
+ * Registry where all views implementing [PlatformRootForTest] should be registered while they
  * are attached to the window. This registry is used by the testing library to query the roots'
  * state.
  */
 @OptIn(InternalComposeUiApi::class)
-internal class ComposeRootRegistry {
+internal class ComposeRootRegistry : PlatformContext.RootForTestListener {
     private val lock = Any()
-    private val roots = mutableSetOf<SkiaRootForTest>()
+    private val roots = mutableSetOf<PlatformRootForTest>()
 
     /**
-     * Returns if the registry is setup to receive registrations from [SkiaRootForTest]s
+     * Returns if the registry is setup to receive registrations from [PlatformRootForTest]s
      */
-    val isSetUp: Boolean
-        get() = SkiaRootForTest.onRootCreatedCallback == ::onRootCreated
+    private var isTracking = false
 
     /**
-     * Sets up this registry to be notified of any [SkiaRootForTest] created
+     * Sets up this registry to be notified of any [PlatformRootForTest] created
      */
     private fun setupRegistry() {
-        SkiaRootForTest.onRootCreatedCallback = ::onRootCreated
-        SkiaRootForTest.onRootDisposedCallback = ::onRootDisposed
+        isTracking = true
     }
 
     /**
      * Cleans up the changes made by [setupRegistry]. Call this after your test has run.
      */
     private fun tearDownRegistry() {
         // Stop accepting new roots
-        SkiaRootForTest.onRootCreatedCallback = null
-        SkiaRootForTest.onRootDisposedCallback = null
+        isTracking = false
         synchronized(lock) {
             // Clear all references
             roots.clear()
         }
     }
 
-    private fun onRootCreated(root: SkiaRootForTest) {
+    override fun onRootForTestCreated(root: PlatformRootForTest) {
         synchronized(lock) {
-            if (isSetUp) {
+            if (isTracking) {
                 roots.add(root)
             }
         }
     }
 
-    private fun onRootDisposed(root: SkiaRootForTest) {
+    override fun onRootForTestDisposed(root: PlatformRootForTest) {
         synchronized(lock) {
-            if (isSetUp) {
+            if (isTracking) {
                 roots.remove(root)
             }
         }
     }
 
     /**
-     * Returns a copy of the set of all registered [SkiaRootForTest]s that can be interacted with.
+     * Returns a copy of the set of all registered [PlatformRootForTest]s that can be interacted with.
      */
-    fun getComposeRoots(): Set<SkiaRootForTest> {
+    fun getComposeRoots(): Set<PlatformRootForTest> {
         return synchronized(lock) { roots.toSet() }
     }
 

compose/ui/ui-test/src/desktopMain/kotlin/androidx/compose/ui/test/DesktopInputDispatcher.desktop.kt

@@ -26,11 +26,6 @@ import androidx.compose.ui.input.key.KeyEvent
 import androidx.compose.ui.input.key.KeyEventType
 import androidx.compose.ui.input.key.nativeKeyCode
 import androidx.compose.ui.input.key.nativeKeyLocation
-import androidx.compose.ui.input.pointer.PointerButton
-import androidx.compose.ui.input.pointer.PointerEventType
-import androidx.compose.ui.input.pointer.PointerType
-import androidx.compose.ui.node.RootForTest
-import androidx.compose.ui.platform.SkiaRootForTest
 import java.awt.Component
 import java.awt.event.InputEvent