Clear topTransparentFullscreenTask from repository if another task opens

The DesktopTransistionObserver does not receive the close or to back
transition for the top transparent fullscreen task causing it to not be
cleared correctly. This leads to freeform windows opening outside of
desktop as we think desktop stop is still showing.

Instead, if the top transparent fullscreen task has not been cleared as
another task opens, or is brought to front, clear the top transparent
fullscreen task as it is no longer needed.

Flag: com.android.window.flags.include_top_transparent_fullscreen_task_in_desktop_heuristic
Fixes: 398167855

Test: atest WMShellUnitTests:DesktopTasksTransitionObserverTest
Change-Id: I737d24c1f143843270f554d4828b7f6a5fce063c

2 files changed, 69 insertions, 12 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserver.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserver.kt
index 7dabeb7c9d15..2ec6105e5af9 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserver.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserver.kt
@@ -38,6 +38,8 @@ import com.android.wm.shell.desktopmode.DesktopModeTransitionTypes.isExitDesktop
 import com.android.wm.shell.desktopmode.desktopwallpaperactivity.DesktopWallpaperActivityTokenProvider
 import com.android.wm.shell.protolog.ShellProtoLogGroup.WM_SHELL_DESKTOP_MODE
 import com.android.wm.shell.shared.TransitionUtil
+import com.android.wm.shell.shared.TransitionUtil.isClosingMode
+import com.android.wm.shell.shared.TransitionUtil.isOpeningMode
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus
 import com.android.wm.shell.sysui.ShellInit
 import com.android.wm.shell.transition.Transitions
@@ -345,18 +347,29 @@ class DesktopTasksTransitionObserver(
     }
 
     private fun updateTopTransparentFullscreenTaskId(info: TransitionInfo) {
-        info.changes.forEach { change ->
-            change.taskInfo?.let { task ->
-                val desktopRepository = desktopUserRepositories.getProfile(task.userId)
-                val displayId = task.displayId
-                // Clear `topTransparentFullscreenTask` information from repository if task
-                // is closed or sent to back.
-                if (
-                    TransitionUtil.isClosingMode(change.mode) &&
-                        task.taskId ==
-                            desktopRepository.getTopTransparentFullscreenTaskId(displayId)
-                ) {
-                    desktopRepository.clearTopTransparentFullscreenTaskId(displayId)
+        run forEachLoop@{
+            info.changes.forEach { change ->
+                change.taskInfo?.let { task ->
+                    val desktopRepository = desktopUserRepositories.getProfile(task.userId)
+                    val displayId = task.displayId
+                    val transparentTaskId =
+                        desktopRepository.getTopTransparentFullscreenTaskId(displayId)
+                    if (transparentTaskId == null) return@forEachLoop
+                    val changeMode = change.mode
+                    val taskId = task.taskId
+                    val isTopTransparentFullscreenTaskClosing =
+                        taskId == transparentTaskId && isClosingMode(changeMode)
+                    val isNonTopTransparentFullscreenTaskOpening =
+                        taskId != transparentTaskId && isOpeningMode(changeMode)
+                    // Clear `topTransparentFullscreenTask` information from repository if task
+                    // is closed, sent to back or if a different task is opened, brought to front.
+                    if (
+                        isTopTransparentFullscreenTaskClosing ||
+                            isNonTopTransparentFullscreenTaskOpening
+                    ) {
+                        desktopRepository.clearTopTransparentFullscreenTaskId(displayId)
+                        return@forEachLoop
+                    }
                 }
             }
         }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserverTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserverTest.kt
index a7dc706eb6c9..ac9a509ac6cb 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserverTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksTransitionObserverTest.kt
@@ -336,6 +336,50 @@ class DesktopTasksTransitionObserverTest {
     }
 
     @Test
+    @EnableFlags(
+        Flags.FLAG_ENABLE_DESKTOP_WINDOWING_MODALS_POLICY,
+        Flags.FLAG_INCLUDE_TOP_TRANSPARENT_FULLSCREEN_TASK_IN_DESKTOP_HEURISTIC,
+    )
+    fun nonTopTransparentTaskOpened_clearTopTransparentTaskIdFromRepository() {
+        val mockTransition = Mockito.mock(IBinder::class.java)
+        val topTransparentTask = createTaskInfo(1)
+        val nonTopTransparentTask = createTaskInfo(2)
+        whenever(taskRepository.getTopTransparentFullscreenTaskId(any()))
+            .thenReturn(topTransparentTask.taskId)
+
+        transitionObserver.onTransitionReady(
+            transition = mockTransition,
+            info = createOpenChangeTransition(nonTopTransparentTask),
+            startTransaction = mock(),
+            finishTransaction = mock(),
+        )
+
+        verify(taskRepository).clearTopTransparentFullscreenTaskId(topTransparentTask.displayId)
+    }
+
+    @Test
+    @EnableFlags(
+        Flags.FLAG_ENABLE_DESKTOP_WINDOWING_MODALS_POLICY,
+        Flags.FLAG_INCLUDE_TOP_TRANSPARENT_FULLSCREEN_TASK_IN_DESKTOP_HEURISTIC,
+    )
+    fun nonTopTransparentTaskSentToFront_clearTopTransparentTaskIdFromRepository() {
+        val mockTransition = Mockito.mock(IBinder::class.java)
+        val topTransparentTask = createTaskInfo(1)
+        val nonTopTransparentTask = createTaskInfo(2)
+        whenever(taskRepository.getTopTransparentFullscreenTaskId(any()))
+            .thenReturn(topTransparentTask.taskId)
+
+        transitionObserver.onTransitionReady(
+            transition = mockTransition,
+            info = createToFrontTransition(nonTopTransparentTask),
+            startTransaction = mock(),
+            finishTransaction = mock(),
+        )
+
+        verify(taskRepository).clearTopTransparentFullscreenTaskId(topTransparentTask.displayId)
+    }
+
+    @Test
     fun transitCloseWallpaper_wallpaperActivityVisibilitySaved() {
         val wallpaperTask = createWallpaperTaskInfo()