Remove windowing mode override from task when it matches display

When a task is moving from desktop to fullscreen or vice versa, check if
the desired windowing mode matches the display windowing mode. If it
does, remove the windowing mode override and set it to undefined.

Fixes an issue with split screen where a task that has been on desktop,
is not eligible to be in split anymore. As the task had windowing mode
overridden to fullscreen.

Bug: 285358244
Test: atest DesktopTasksControllerTest
Test: move Chrome to freeform and back to fullscreen, use "new window"
  from the menu to create a new chrome window in split screen
Change-Id: I7b683e1cf2353c5cfa58bd1d7d3ab1b5319c9be7

libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt

@@ -38,7 +38,6 @@ import android.view.WindowManager.TRANSIT_OPEN
 import android.view.WindowManager.TRANSIT_TO_FRONT
 import android.window.TransitionInfo
 import android.window.TransitionRequestInfo
-import android.window.WindowContainerToken
 import android.window.WindowContainerTransaction
 import androidx.annotation.BinderThread
 import com.android.wm.shell.RootTaskDisplayAreaOrganizer
@@ -184,7 +183,7 @@ class DesktopTasksController(
         )
         // Bring other apps to front first
         bringDesktopAppsToFront(task.displayId, wct)
-        addMoveToDesktopChanges(wct, task.token)
+        addMoveToDesktopChanges(wct, task)
 
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
             transitions.startTransition(TRANSIT_CHANGE, wct, null /* handler */)
@@ -205,7 +204,7 @@ class DesktopTasksController(
         )
         val wct = WindowContainerTransaction()
         moveHomeTaskToFront(wct)
-        addMoveToDesktopChanges(wct, taskInfo.getToken())
+        addMoveToDesktopChanges(wct, taskInfo)
         wct.setBounds(taskInfo.token, startBounds)
 
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
@@ -225,7 +224,7 @@ class DesktopTasksController(
         )
         val wct = WindowContainerTransaction()
         bringDesktopAppsToFront(taskInfo.displayId, wct)
-        addMoveToDesktopChanges(wct, taskInfo.getToken())
+        addMoveToDesktopChanges(wct, taskInfo)
         wct.setBounds(taskInfo.token, freeformBounds)
 
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
@@ -251,7 +250,7 @@ class DesktopTasksController(
         )
 
         val wct = WindowContainerTransaction()
-        addMoveToFullscreenChanges(wct, task.token)
+        addMoveToFullscreenChanges(wct, task)
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
             transitions.startTransition(TRANSIT_CHANGE, wct, null /* handler */)
         } else {
@@ -270,7 +269,7 @@ class DesktopTasksController(
                 task.taskId
         )
         val wct = WindowContainerTransaction()
-        addMoveToFullscreenChanges(wct, task.token)
+        addMoveToFullscreenChanges(wct, task)
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
             enterDesktopTaskTransitionHandler.startCancelMoveToDesktopMode(wct, position,
                     mOnAnimationFinishedCallback)
@@ -287,7 +286,7 @@ class DesktopTasksController(
                 task.taskId
         )
         val wct = WindowContainerTransaction()
-        addMoveToFullscreenChanges(wct, task.token)
+        addMoveToFullscreenChanges(wct, task)
 
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
             exitDesktopTaskTransitionHandler.startTransition(
@@ -516,7 +515,7 @@ class DesktopTasksController(
                     task.taskId
             )
             return WindowContainerTransaction().also { wct ->
-                addMoveToFullscreenChanges(wct, task.token)
+                addMoveToFullscreenChanges(wct, task)
             }
         }
         return null
@@ -532,7 +531,7 @@ class DesktopTasksController(
                     task.taskId
             )
             return WindowContainerTransaction().also { wct ->
-                addMoveToDesktopChanges(wct, task.token)
+                addMoveToDesktopChanges(wct, task)
             }
         }
         return null
@@ -546,30 +545,44 @@ class DesktopTasksController(
         )
         val wct = WindowContainerTransaction()
         bringDesktopAppsToFront(task.displayId, wct)
-        addMoveToDesktopChanges(wct, task.token)
+        addMoveToDesktopChanges(wct, task)
         desktopModeTaskRepository.setStashed(task.displayId, false)
         return wct
     }
 
     private fun addMoveToDesktopChanges(
         wct: WindowContainerTransaction,
-        token: WindowContainerToken
+        taskInfo: RunningTaskInfo
     ) {
-        wct.setWindowingMode(token, WINDOWING_MODE_FREEFORM)
-        wct.reorder(token, true /* onTop */)
+        val displayWindowingMode = taskInfo.configuration.windowConfiguration.displayWindowingMode
+        val targetWindowingMode = if (displayWindowingMode == WINDOWING_MODE_FREEFORM) {
+            // Display windowing is freeform, set to undefined and inherit it
+            WINDOWING_MODE_UNDEFINED
+        } else {
+            WINDOWING_MODE_FREEFORM
+        }
+        wct.setWindowingMode(taskInfo.token, targetWindowingMode)
+        wct.reorder(taskInfo.token, true /* onTop */)
         if (isDesktopDensityOverrideSet()) {
-            wct.setDensityDpi(token, getDesktopDensityDpi())
+            wct.setDensityDpi(taskInfo.token, getDesktopDensityDpi())
         }
     }
 
     private fun addMoveToFullscreenChanges(
         wct: WindowContainerTransaction,
-        token: WindowContainerToken
+        taskInfo: RunningTaskInfo
     ) {
-        wct.setWindowingMode(token, WINDOWING_MODE_FULLSCREEN)
-        wct.setBounds(token, null)
+        val displayWindowingMode = taskInfo.configuration.windowConfiguration.displayWindowingMode
+        val targetWindowingMode = if (displayWindowingMode == WINDOWING_MODE_FULLSCREEN) {
+            // Display windowing is fullscreen, set to undefined and inherit it
+            WINDOWING_MODE_UNDEFINED
+        } else {
+            WINDOWING_MODE_FULLSCREEN
+        }
+        wct.setWindowingMode(taskInfo.token, targetWindowingMode)
+        wct.setBounds(taskInfo.token, null)
         if (isDesktopDensityOverrideSet()) {
-            wct.setDensityDpi(token, getFullscreenDensityDpi())
+            wct.setDensityDpi(taskInfo.token, getFullscreenDensityDpi())
         }
     }
 

libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt

@@ -270,14 +270,25 @@ class DesktopTasksControllerTest : ShellTestCase() {
     }
 
     @Test
-    fun moveToDesktop() {
+    fun moveToDesktop_displayFullscreen_windowingModeSetToFreeform() {
         val task = setUpFullscreenTask()
+        task.configuration.windowConfiguration.displayWindowingMode = WINDOWING_MODE_FULLSCREEN
         controller.moveToDesktop(task)
         val wct = getLatestWct(expectTransition = TRANSIT_CHANGE)
         assertThat(wct.changes[task.token.asBinder()]?.windowingMode)
             .isEqualTo(WINDOWING_MODE_FREEFORM)
     }
 
+    @Test
+    fun moveToDesktop_displayFreeform_windowingModeSetToUndefined() {
+        val task = setUpFullscreenTask()
+        task.configuration.windowConfiguration.displayWindowingMode = WINDOWING_MODE_FREEFORM
+        controller.moveToDesktop(task)
+        val wct = getLatestWct(expectTransition = TRANSIT_CHANGE)
+        assertThat(wct.changes[task.token.asBinder()]?.windowingMode)
+                .isEqualTo(WINDOWING_MODE_UNDEFINED)
+    }
+
     @Test
     fun moveToDesktop_nonExistentTask_doesNothing() {
         controller.moveToDesktop(999)
@@ -325,12 +336,23 @@ class DesktopTasksControllerTest : ShellTestCase() {
     }
 
     @Test
-    fun moveToFullscreen() {
+    fun moveToFullscreen_displayFullscreen_windowingModeSetToUndefined() {
         val task = setUpFreeformTask()
+        task.configuration.windowConfiguration.displayWindowingMode = WINDOWING_MODE_FULLSCREEN
         controller.moveToFullscreen(task)
         val wct = getLatestWct(expectTransition = TRANSIT_CHANGE)
         assertThat(wct.changes[task.token.asBinder()]?.windowingMode)
-            .isEqualTo(WINDOWING_MODE_FULLSCREEN)
+            .isEqualTo(WINDOWING_MODE_UNDEFINED)
+    }
+
+    @Test
+    fun moveToFullscreen_displayFreeform_windowingModeSetToFullscreen() {
+        val task = setUpFreeformTask()
+        task.configuration.windowConfiguration.displayWindowingMode = WINDOWING_MODE_FREEFORM
+        controller.moveToFullscreen(task)
+        val wct = getLatestWct(expectTransition = TRANSIT_CHANGE)
+        assertThat(wct.changes[task.token.asBinder()]?.windowingMode)
+                .isEqualTo(WINDOWING_MODE_FULLSCREEN)
     }
 
     @Test