Rename LocalWindow to LocalAwtWindow, make it public and provide it in ComposePanel (JetBrains#3007)

Author: m-sasha

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

@@ -17,6 +17,10 @@
 package androidx.compose.ui.awt
 
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.ComposeFeatureFlags
 import androidx.compose.ui.ComposeUiFlags
 import androidx.compose.ui.ExperimentalComposeUiApi
@@ -37,10 +41,12 @@ import java.awt.ComponentOrientation
 import java.awt.Container
 import java.awt.Dimension
 import java.awt.FocusTraversalPolicy
+import java.awt.Window
 import java.awt.event.FocusEvent
 import java.awt.event.FocusListener
 import java.util.*
 import javax.swing.JLayeredPane
+import javax.swing.SwingUtilities
 import javax.swing.SwingUtilities.isEventDispatchThread
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
@@ -122,6 +128,8 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         isFocusable = true
     }
 
+    private var windowParent by mutableStateOf<Window?>(null)
+
     private val _focusListeners = mutableSetOf<FocusListener?>()
 
     private var _composeContainer: ComposeContainer? = null
@@ -231,8 +239,17 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         // to keep the lambda describing composable content and set the content only when
         // everything is ready to avoid accidental crashes and memory leaks on all supported OS
         // types.
-        _composeContent = content
-        _composeContainer?.setContent(content)
+        val wrappedContent = wrapContent(content)
+        _composeContent = wrappedContent
+        _composeContainer?.setContent(wrappedContent)
+    }
+
+    private fun wrapContent(content: @Composable () -> Unit): @Composable () -> Unit {
+        return {
+            CompositionLocalProvider(LocalAwtWindow provides windowParent) {
+                content()
+            }
+        }
     }
 
     /**
@@ -286,6 +303,7 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         // content.
         val composeContainer = _composeContainer ?: createComposeContainer().also {
             _composeContainer = it
+            windowParent = SwingUtilities.getWindowAncestor(this)
             it.redispatchUnconsumedMouseWheelEvents = redispatchUnconsumedMouseWheelEvents
             @OptIn(InternalCoreApi::class)
             it.showLayoutBounds = showLayoutBounds
@@ -342,6 +360,7 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         if (isDisposeOnRemove) {
             dispose()
         }
+        windowParent = null
         super.removeNotify()
     }
 

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

@@ -23,7 +23,6 @@ import androidx.compose.ui.LayerType
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.input.key.KeyEvent
 import androidx.compose.ui.scene.ComposeContainer
-import androidx.compose.ui.window.LocalWindow
 import androidx.savedstate.SavedState
 import java.awt.Component
 import java.awt.Container
@@ -151,7 +150,7 @@ internal class ComposeWindowPanel(
         )
         composeContainer.setContent {
             CompositionLocalProvider(
-                LocalWindow provides window
+                LocalAwtWindow provides window
             ) {
                 WindowContentLayout(modifier, content)
             }

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/LocalAwtWindow.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2026 The Android Open Source Project
+ *
+ * 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 androidx.compose.ui.awt
+
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.ExperimentalComposeUiApi
+import androidx.compose.ui.ImageComposeScene
+
+/**
+ * Window-owner of the current composition.
+ *
+ * This could be:
+ * - A Compose window, e.g., [ComposeWindow] or [ComposeDialog]
+ * - A non-Compose window, e.g., [java.awt.Frame] or [java.awt.Dialog] if Compose is embedded into
+ *   Swing via [ComposePanel].
+ * - `null`, if the current composition is not inside a window, such as in unit tests, or with
+ *   [ImageComposeScene].
+ */
+@ExperimentalComposeUiApi
+val LocalAwtWindow = staticCompositionLocalOf<java.awt.Window?> { null }

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

@@ -41,7 +41,6 @@ import androidx.compose.ui.window.DialogModalityType
 import androidx.compose.ui.window.DialogState
 import androidx.compose.ui.window.DialogWindow
 import androidx.compose.ui.window.DialogWindowScope
-import androidx.compose.ui.window.LocalWindow
 import androidx.compose.ui.window.LocalWindowExceptionHandlerFactory
 import androidx.compose.ui.window.UndecoratedWindowDecoration
 import androidx.compose.ui.window.WindowDecoration
@@ -201,7 +200,7 @@ fun SwingDialog(
     init: (ComposeDialog) -> Unit,
     content: @Composable DialogWindowScope.() -> Unit
 ) {
-    val owner = LocalWindow.current
+    val owner = LocalAwtWindow.current
 
     val currentState by rememberUpdatedState(state)
     val currentTitle by rememberUpdatedState(title)

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

@@ -23,8 +23,6 @@ import androidx.compose.ui.layout.layoutId
 import androidx.compose.ui.unit.Constraints
 import androidx.compose.ui.util.fastForEach
 import androidx.compose.ui.util.fastMaxOfOrDefault
-import androidx.compose.ui.util.fastMaxOfOrNull
-import androidx.compose.ui.window.LocalWindow
 
 /**
  * Base layout for full-window Compose content.
@@ -34,7 +32,7 @@ internal fun WindowContentLayout(
     modifier: Modifier = Modifier,
     content: @Composable () -> Unit
 ) {
-    val window = requireNotNull(LocalWindow.current)
+    val window = requireNotNull(LocalAwtWindow.current)
     Layout(
         content = content,
         modifier = modifier,

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/scene/skia/WindowSkiaLayerComponent.desktop.kt

@@ -116,6 +116,11 @@ internal class WindowSkiaLayerComponent(
             inputMethodsEnabled = enable
             super.enableInputMethods(enable)
         }
+
+        override fun dispose() {
+            super.dispose()
+            isDisposed = true
+        }
     }
 
     override val contentRoot: Component
@@ -150,16 +155,21 @@ internal class WindowSkiaLayerComponent(
 
     override val windowHandle by hierarchyRoot::windowHandle
 
+    private var isDisposed = false
+
     init {
         hierarchyRoot.renderDelegate = renderDelegate
     }
 
     override fun dispose() {
         hierarchyRoot.dispose()
+        isDisposed = true
     }
 
     override fun onComposeInvalidation() {
-        hierarchyRoot.needRender()
+        if (!isDisposed) {
+            hierarchyRoot.needRender()
+        }
     }
 
     override fun renderImmediately() {

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/window/LocalWindow.kt

@@ -73,6 +73,7 @@ import com.google.common.truth.Truth.assertThat
 import java.awt.BorderLayout
 import java.awt.Dimension
 import java.awt.GraphicsEnvironment
+import java.awt.Window
 import java.awt.event.MouseEvent
 import javax.swing.BoxLayout
 import javax.swing.JFrame
@@ -938,4 +939,27 @@ class ComposePanelTest {
             frame.dispose()
         }
     }
+
+    @Test
+    fun `ComposePanel provides LocalAwtWindow`() = runApplicationTest {
+        var localWindow: Window? = null
+        val composePanel = ComposePanel().apply {
+            size = Dimension(300, 300)
+            setContent {
+                localWindow = LocalAwtWindow.current
+            }
+        }
+        val frame = JFrame().apply {
+            contentPane.add(composePanel)
+            size = Dimension(300, 300)
+        }
+
+        try {
+            frame.isVisible = true
+            awaitIdle()
+            assertNotNull(localWindow)
+        } finally {
+            frame.dispose()
+        }
+    }
 }

compose/ui/ui/src/desktopTest/kotlin/androidx/compose/ui/awt/ComposePanelTest.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.*
 import androidx.compose.runtime.saveable.rememberSaveableStateHolder
 import androidx.compose.ui.*
 import androidx.compose.ui.awt.ComposeDialog
+import androidx.compose.ui.awt.LocalAwtWindow
 import androidx.compose.ui.awt.SwingDialog
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
@@ -53,6 +54,7 @@ import javax.swing.JFrame
 import kotlin.concurrent.thread
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
 import kotlinx.coroutines.delay
 
 class DialogWindowTest {
@@ -827,6 +829,18 @@ class DialogWindowTest {
             content()
         }
     }
+
+    @Test
+    fun dialogWindowComposableProvidesLocalAwtWindow() = runApplicationTest {
+        var localWindow: Window? = null
+        launchTestApplication {
+            DialogWindow(onCloseRequest = ::exitApplication) {
+                localWindow = LocalAwtWindow.current
+            }
+        }
+        awaitIdle()
+        assertNotNull(localWindow)
+    }
 }
 
 private fun assertDialogStateEquals(expected: DialogState, actual: DialogState) {

compose/ui/ui/src/desktopTest/kotlin/androidx/compose/ui/window/DialogWindowTest.kt

@@ -25,6 +25,7 @@ import androidx.compose.material.Slider
 import androidx.compose.runtime.*
 import androidx.compose.ui.*
 import androidx.compose.ui.awt.ComposeWindow
+import androidx.compose.ui.awt.LocalAwtWindow
 import androidx.compose.ui.awt.SwingWindow
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
@@ -46,6 +47,7 @@ import kotlin.math.roundToInt
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
+import kotlin.test.assertNotNull
 import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Duration.Companion.seconds
 import kotlinx.coroutines.*
@@ -880,6 +882,18 @@ class WindowTest {
             content()
         }
     }
+
+    @Test
+    fun windowComposableProvidesLocalAwtWindow() = runApplicationTest {
+        var localWindow: Window? = null
+        launchTestApplication {
+            Window(onCloseRequest = ::exitApplication) {
+                localWindow = LocalAwtWindow.current
+            }
+        }
+        awaitIdle()
+        assertNotNull(localWindow)
+    }
 }
 
 private object CtxElement : CoroutineContext.Element, CoroutineContext.Key<CtxElement> {