Adapt focus interop code to Compose 1.7 changes

Fixes JetBrains/compose-multiplatform#2944
Fixes JetBrains/compose-multiplatform#4919
Fixes https://youtrack.jetbrains.com/issue/COMPOSE-1212/Integration.-Check-changes-in-FocusOwnerImpl

After https://android-review.googlesource.com/c/platform/frameworks/support/+/2813125, there are some changes that affected our code for focus interop with ComposePanel/SwingPanel:
- the root node no longer focusable
- FocusOwnerImpl now has iterop callbacks and our own modification of this file (in jb-main, integration was reset) doesn't work anymore

## Testing
- added new tests
- ComposeFocusTest now pass

## Release notes
### Fixes - Multiple platforms
- Fix "ComposePanel. Focus moves to child after focusing/unfocusing the main window"

compose/ui/ui/api/desktop/ui.api

@@ -151,10 +151,7 @@ public final class androidx/compose/ui/ComposeScene {
 	public final fun getLayoutDirection ()Landroidx/compose/ui/unit/LayoutDirection;
 	public final fun getRoots ()Ljava/util/Set;
 	public final fun hasInvalidations ()Z
-	public final fun moveFocus-3ESFkO8 (I)Z
-	public final fun releaseFocus ()V
 	public final fun render (Lorg/jetbrains/skia/Canvas;J)V
-	public final fun requestFocus ()V
 	public final fun sendKeyEvent-ZmokQxo (Ljava/lang/Object;)Z
 	public final fun sendPointerEvent-BGSDPeU (IJJJILandroidx/compose/ui/input/pointer/PointerButtons;Landroidx/compose/ui/input/pointer/PointerKeyboardModifiers;Ljava/lang/Object;Landroidx/compose/ui/input/pointer/PointerButton;)V
 	public static synthetic fun sendPointerEvent-BGSDPeU$default (Landroidx/compose/ui/ComposeScene;IJJJILandroidx/compose/ui/input/pointer/PointerButtons;Landroidx/compose/ui/input/pointer/PointerKeyboardModifiers;Ljava/lang/Object;Landroidx/compose/ui/input/pointer/PointerButton;ILjava/lang/Object;)V
@@ -3501,8 +3498,7 @@ public final class androidx/compose/ui/scene/ComposeSceneContext$Companion {
 
 public abstract interface class androidx/compose/ui/scene/ComposeSceneFocusManager : androidx/compose/ui/focus/FocusManager {
 	public abstract fun getFocusRect ()Landroidx/compose/ui/geometry/Rect;
-	public abstract fun releaseFocus ()V
-	public abstract fun requestFocus ()V
+	public abstract fun getHasFocus ()Z
 }
 
 public abstract interface class androidx/compose/ui/scene/ComposeSceneLayer {

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/ComposePanel.desktop.kt

@@ -198,7 +198,6 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
             skiaLayerAnalytics = skiaLayerAnalytics,
             windowContainer = windowContainer
         ).apply {
-            focusManager.releaseFocus()
             setBounds(0, 0, width, height)
             contentComponent.isFocusable = isFocusable
             contentComponent.isRequestFocusEnabled = isRequestFocusEnabled
@@ -207,19 +206,12 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
             _focusListeners.forEach(contentComponent::addFocusListener)
             contentComponent.addFocusListener(object : FocusListener {
                 override fun focusGained(e: FocusEvent) {
-                    // The focus can be switched from the child component inside SwingPanel.
-                    // In that case, SwingPanel will take care of it.
-                    if (!isParentOf(e.oppositeComponent)) {
-                        focusManager.requestFocus()
+                    if (!e.isTemporary && !e.isFocusGainedHandledBySwingPanel(this@ComposePanel)) {
                         when (e.cause) {
-                            FocusEvent.Cause.TRAVERSAL_FORWARD -> {
-                                focusManager.moveFocus(FocusDirection.Next)
-                            }
-                            FocusEvent.Cause.TRAVERSAL_BACKWARD -> {
-                                focusManager.moveFocus(FocusDirection.Previous)
-                            }
                             FocusEvent.Cause.UNKNOWN, FocusEvent.Cause.ACTIVATION -> {
-                                focusManager.moveFocus(FocusDirection.Enter)
+                                if (!focusManager.hasFocus) {
+                                    focusManager.takeFocus(FocusDirection.Next)
+                                }
                             }
                             else -> Unit
                         }

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/SwingPanel.desktop.kt

@@ -125,7 +125,7 @@ public fun <T : Component> SwingPanel(
     DisposableEffect(Unit) {
         val focusListener = object : FocusListener {
             override fun focusGained(e: FocusEvent) {
-                if (interopComponent.container.isParentOf(e.oppositeComponent)) {
+                if (e.isFocusGainedHandledBySwingPanel(interopComponent.container)) {
                     when (e.cause) {
                         FocusEvent.Cause.TRAVERSAL_FORWARD -> focusSwitcher.moveForward()
                         FocusEvent.Cause.TRAVERSAL_BACKWARD -> focusSwitcher.moveBackward()
@@ -156,6 +156,19 @@ public fun <T : Component> SwingPanel(
     }
 }
 
+/**
+ * true, if the event is handled by SwingPanel.
+ *
+ * The focus can be switched from the child component inside SwingPanel.
+ * In that case, SwingPanel will take care of it.
+ *
+ * The alternative that needs more investigation is to
+ * not use ComposePanel as next/previous focus element for SwingPanel children
+ * (see [SwingPanelContainer.focusComponent])
+ */
+internal fun FocusEvent.isFocusGainedHandledBySwingPanel(container: Container) =
+    container.isParentOf(oppositeComponent)
+
 /**
  * A container for [SwingPanel]'s component. Takes care about focus and clipping.
  *
@@ -194,67 +207,77 @@ private class FocusSwitcher<T : Component>(
     private val interopComponent: SwingInteropComponent<T>,
     private val focusManager: FocusManager,
 ) {
-    private val backwardRequester = FocusRequester()
-    private val forwardRequester = FocusRequester()
-    private var isRequesting = false
+    private val backwardTracker = FocusTracker {
+        val container = interopComponent.container
+        val component = container.focusTraversalPolicy.getFirstComponent(container)
+        if (component != null) {
+            component.requestFocus(FocusEvent.Cause.TRAVERSAL_FORWARD)
+        } else {
+            moveForward()
+        }
+    }
 
-    fun moveBackward() {
-        try {
-            isRequesting = true
-            backwardRequester.requestFocus()
-        } finally {
-            isRequesting = false
+    private val forwardTracker = FocusTracker {
+        val component = interopComponent.container.focusTraversalPolicy.getLastComponent(interopComponent.container)
+        if (component != null) {
+            component.requestFocus(FocusEvent.Cause.TRAVERSAL_BACKWARD)
+        } else {
+            moveBackward()
         }
+    }
+
+    fun moveBackward() {
+        backwardTracker.requestFocusWithoutEvent()
         focusManager.moveFocus(FocusDirection.Previous)
     }
 
     fun moveForward() {
-        try {
-            isRequesting = true
-            forwardRequester.requestFocus()
-        } finally {
-            isRequesting = false
-        }
+        forwardTracker.requestFocusWithoutEvent()
         focusManager.moveFocus(FocusDirection.Next)
     }
 
     @Composable
     fun Content() {
-        EmptyLayout(
-            Modifier
-                .focusRequester(backwardRequester)
-                .onFocusEvent {
-                    if (it.isFocused && !isRequesting) {
-                        focusManager.clearFocus(force = true)
-
-                        val container = interopComponent.container
-                        val component = container.focusTraversalPolicy.getFirstComponent(container)
-                        if (component != null) {
-                            component.requestFocus(FocusEvent.Cause.TRAVERSAL_FORWARD)
-                        } else {
-                            moveForward()
-                        }
-                    }
-                }
-                .focusTarget()
-        )
-        EmptyLayout(
-            Modifier
-                .focusRequester(forwardRequester)
-                .onFocusEvent {
-                    if (it.isFocused && !isRequesting) {
-                        focusManager.clearFocus(force = true)
-
-                        val component = interopComponent.container.focusTraversalPolicy.getLastComponent(interopComponent.container)
-                        if (component != null) {
-                            component.requestFocus(FocusEvent.Cause.TRAVERSAL_BACKWARD)
-                        } else {
-                            moveBackward()
-                        }
+        EmptyLayout(backwardTracker.modifier)
+        EmptyLayout(forwardTracker.modifier)
+    }
+
+    /**
+     * A helper class that can help:
+     * - to prevent recursive focus events
+     *   (a case when we focus the same element inside `onFocusEvent`)
+     * - to prevent triggering `onFocusEvent` while requesting focus somewhere else
+     */
+    private class FocusTracker(
+        private val onNonRecursiveFocused: () -> Unit
+    ) {
+        private val requester = FocusRequester()
+
+        private var isRequestingFocus = false
+        private var isHandlingFocus = false
+
+        fun requestFocusWithoutEvent() {
+            try {
+                isRequestingFocus = true
+                requester.requestFocus()
+            } finally {
+                isRequestingFocus = false
+            }
+        }
+
+        val modifier = Modifier
+            .focusRequester(requester)
+            .onFocusEvent {
+                if (!isRequestingFocus && !isHandlingFocus && it.isFocused) {
+                    try {
+                        isHandlingFocus = true
+                        onNonRecursiveFocused()
+                    } finally {
+                        isHandlingFocus = false
                     }
                 }
-                .focusTarget()
-        )
+            }
+            .focusTarget()
     }
 }
 

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/scene/ComposeSceneMediator.desktop.kt

@@ -24,6 +24,7 @@ import androidx.compose.ui.awt.AwtEventListener
 import androidx.compose.ui.awt.AwtEventListeners
 import androidx.compose.ui.awt.OnlyValidPrimaryMouseButtonFilter
 import androidx.compose.ui.awt.SwingInteropContainer
+import androidx.compose.ui.awt.isFocusGainedHandledBySwingPanel
 import androidx.compose.ui.awt.runOnEDTThread
 import androidx.compose.ui.focus.FocusDirection
 import androidx.compose.ui.focus.FocusManager
@@ -68,6 +69,9 @@ import java.awt.Toolkit
 import java.awt.event.ContainerEvent
 import java.awt.event.ContainerListener
 import java.awt.event.FocusEvent
+import java.awt.event.FocusEvent.Cause.TRAVERSAL
+import java.awt.event.FocusEvent.Cause.TRAVERSAL_BACKWARD
+import java.awt.event.FocusEvent.Cause.TRAVERSAL_FORWARD
 import java.awt.event.FocusListener
 import java.awt.event.InputEvent
 import java.awt.event.InputMethodEvent
@@ -215,8 +219,20 @@ internal class ComposeSceneMediator(
             // We don't reset focus for Compose when the component loses focus temporary.
             // Partially because we don't support restoring focus after clearing it.
             // Focus can be lost temporary when another window or popup takes focus.
-            if (!e.isTemporary) {
-                scene.focusManager.requestFocus()
+            if (!e.isTemporary && !e.isFocusGainedHandledBySwingPanel(container)) {
+                when (e.cause) {
+                    TRAVERSAL_BACKWARD -> {
+                        if (!focusManager.takeFocus(FocusDirection.Previous)) {
+                            platformContext.parentFocusManager.moveFocus(FocusDirection.Previous)
+                        }
+                    }
+                    TRAVERSAL, TRAVERSAL_FORWARD -> {
+                        if (!focusManager.takeFocus(FocusDirection.Next)) {
+                            platformContext.parentFocusManager.moveFocus(FocusDirection.Next)
+                        }
+                    }
+                    else -> Unit
+                }
             }
         }
 
@@ -651,7 +667,14 @@ internal class ComposeSceneMediator(
         }
         override val parentFocusManager: FocusManager = DesktopFocusManager()
         override fun requestFocus(): Boolean {
-            return contentComponent.hasFocus() || contentComponent.requestFocusInWindow()
+            // Don't check hasFocus(), and don't check the returning result
+            // Swing returns "false" if the window isn't visible or isn't active,
+            // but the component will always receive the focus after activation.
+            //
+            // if we return false - we don't allow changing the focus, and it breaks requesting
+            // focus at start and in inactive mode
+            contentComponent.requestFocusInWindow()
+            return true
         }
 
         override val rootForTestListener