Add support to move task to another display

Create an API in DesktopTasksController to move a task to another
display. It will rotate through the existing displays and move the task
to the next one. If the task is already on the last display, it will
move it back to the first.
Display list is ordered by display ids.
If there is only one display, the method call is a no-op.

Adding a dev option to window caption menu that is behind a flag. This
dev option can be used to move the window.

Bug: 278084491
Test: atest DesktopTasksControllerTest
Test: use a virtual device with multiple displays, use select button to
  move an app between displays

Change-Id: If30b48d04dfa86b64b80e39e63e365bf921a6f92

6 files changed, 141 insertions, 0 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/RootTaskDisplayAreaOrganizer.java b/libs/WindowManager/Shell/src/com/android/wm/shell/RootTaskDisplayAreaOrganizer.java
index 544d75739547..410ae78dba1b 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/RootTaskDisplayAreaOrganizer.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/RootTaskDisplayAreaOrganizer.java
@@ -181,6 +181,17 @@ public class RootTaskDisplayAreaOrganizer extends DisplayAreaOrganizer {
     }
 
     /**
+     * Returns the list of display ids that are tracked by a {@link DisplayAreaInfo}
+     */
+    public int[] getDisplayIds() {
+        int[] displayIds = new int[mDisplayAreasInfo.size()];
+        for (int i = 0; i < mDisplayAreasInfo.size(); i++) {
+            displayIds[i] = mDisplayAreasInfo.keyAt(i);
+        }
+        return displayIds;
+    }
+
+    /**
      * Returns the {@link DisplayAreaInfo} of the {@link DisplayAreaInfo#displayId}.
      */
     @Nullable
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopModeStatus.java b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopModeStatus.java
index d1760ed75547..76ca68bbfa75 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopModeStatus.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopModeStatus.java
@@ -49,6 +49,12 @@ public class DesktopModeStatus {
             "persist.wm.debug.desktop_veiled_resizing", true);
 
     /**
+     * Flag to indicate is moving task to another display is enabled.
+     */
+    public static final boolean IS_DISPLAY_CHANGE_ENABLED = SystemProperties.getBoolean(
+            "persist.wm.debug.desktop_change_display", false);
+
+    /**
      * Return {@code true} if desktop mode support is enabled
      */
     public static boolean isProto1Enabled() {
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index c814fe575e81..73a0e362a744 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -235,6 +235,69 @@ class DesktopTasksController(
     }
 
     /**
+     * Move task to the next display.
+     *
+     * Queries all current known display ids and sorts them in ascending order. Then iterates
+     * through the list and looks for the display id that is larger than the display id for
+     * the passed in task. If a display with a higher id is not found, iterates through the list and
+     * finds the first display id that is not the display id for the passed in task.
+     *
+     * If a display matching the above criteria is found, re-parents the task to that display.
+     * No-op if no such display is found.
+     */
+    fun moveToNextDisplay(taskId: Int) {
+        val task = shellTaskOrganizer.getRunningTaskInfo(taskId)
+        if (task == null) {
+            ProtoLog.w(WM_SHELL_DESKTOP_MODE, "moveToNextDisplay: taskId=%d not found", taskId)
+            return
+        }
+        ProtoLog.v(WM_SHELL_DESKTOP_MODE, "moveToNextDisplay: taskId=%d taskDisplayId=%d",
+                taskId, task.displayId)
+
+        val displayIds = rootTaskDisplayAreaOrganizer.displayIds.sorted()
+        // Get the first display id that is higher than current task display id
+        var newDisplayId = displayIds.firstOrNull { displayId -> displayId > task.displayId }
+        if (newDisplayId == null) {
+            // No display with a higher id, get the first display id that is not the task display id
+            newDisplayId = displayIds.firstOrNull { displayId -> displayId < task.displayId }
+        }
+        if (newDisplayId == null) {
+            ProtoLog.w(WM_SHELL_DESKTOP_MODE, "moveToNextDisplay: next display not found")
+            return
+        }
+        moveToDisplay(task, newDisplayId)
+    }
+
+    /**
+     * Move [task] to display with [displayId].
+     *
+     * No-op if task is already on that display per [RunningTaskInfo.displayId].
+     */
+    private fun moveToDisplay(task: RunningTaskInfo, displayId: Int) {
+        ProtoLog.v(WM_SHELL_DESKTOP_MODE, "moveToDisplay: taskId=%d displayId=%d",
+                task.taskId, displayId)
+
+        if (task.displayId == displayId) {
+            ProtoLog.d(WM_SHELL_DESKTOP_MODE, "moveToDisplay: task already on display")
+            return
+        }
+
+        val displayAreaInfo = rootTaskDisplayAreaOrganizer.getDisplayAreaInfo(displayId)
+        if (displayAreaInfo == null) {
+            ProtoLog.w(WM_SHELL_DESKTOP_MODE, "moveToDisplay: display not found")
+            return
+        }
+
+        val wct = WindowContainerTransaction()
+        wct.reparent(task.token, displayAreaInfo.token, true /* onTop */)
+        if (Transitions.ENABLE_SHELL_TRANSITIONS) {
+            transitions.startTransition(TRANSIT_CHANGE, wct, null /* handler */)
+        } else {
+            shellTaskOrganizer.applyTransaction(wct)
+        }
+    }
+
+    /**
      * Get windowing move for a given `taskId`
      *
      * @return [WindowingMode] for the task or [WINDOWING_MODE_UNDEFINED] if task is not found
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
index 4ef3350d06a4..ff60130a0748 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
@@ -333,6 +333,13 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 decoration.closeHandleMenu();
             } else if (id == R.id.collapse_menu_button) {
                 decoration.closeHandleMenu();
+            } else if (id == R.id.select_button) {
+                if (DesktopModeStatus.IS_DISPLAY_CHANGE_ENABLED) {
+                    // TODO(b/278084491): dev option to enable display switching
+                    //  remove when select is implemented
+                    mDesktopTasksController.ifPresent(c -> c.moveToNextDisplay(mTaskId));
+                    decoration.closeHandleMenu();
+                }
             }
         }
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.java
index ed3cca078084..ac4a597c15d1 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.java
@@ -187,6 +187,8 @@ class HandleMenu {
         final View moreActionsPillView = mMoreActionsPill.mWindowViewHost.getView();
         final Button closeBtn = moreActionsPillView.findViewById(R.id.close_button);
         closeBtn.setOnClickListener(mOnClickListener);
+        final Button selectBtn = moreActionsPillView.findViewById(R.id.select_button);
+        selectBtn.setOnClickListener(mOnClickListener);
     }
 
     /**
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
index f506969f51df..1335ebf105a6 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
@@ -31,6 +31,7 @@ import android.view.WindowManager.TRANSIT_CHANGE
 import android.view.WindowManager.TRANSIT_NONE
 import android.view.WindowManager.TRANSIT_OPEN
 import android.view.WindowManager.TRANSIT_TO_FRONT
+import android.window.DisplayAreaInfo
 import android.window.TransitionRequestInfo
 import android.window.WindowContainerTransaction
 import android.window.WindowContainerTransaction.HierarchyOp.HIERARCHY_OP_TYPE_REORDER
@@ -344,6 +345,57 @@ class DesktopTasksControllerTest : ShellTestCase() {
     }
 
     @Test
+    fun moveToNextDisplay_noOtherDisplays() {
+        whenever(rootTaskDisplayAreaOrganizer.displayIds).thenReturn(intArrayOf(DEFAULT_DISPLAY))
+        val task = setUpFreeformTask(displayId = DEFAULT_DISPLAY)
+        controller.moveToNextDisplay(task.taskId)
+        verifyWCTNotExecuted()
+    }
+
+    @Test
+    fun moveToNextDisplay_moveFromFirstToSecondDisplay() {
+        // Set up two display ids
+        whenever(rootTaskDisplayAreaOrganizer.displayIds)
+                .thenReturn(intArrayOf(DEFAULT_DISPLAY, SECOND_DISPLAY))
+        // Create a mock for the target display area: second display
+        val secondDisplayArea = DisplayAreaInfo(MockToken().token(), SECOND_DISPLAY, 0)
+        whenever(rootTaskDisplayAreaOrganizer.getDisplayAreaInfo(SECOND_DISPLAY))
+                .thenReturn(secondDisplayArea)
+
+        val task = setUpFreeformTask(displayId = DEFAULT_DISPLAY)
+        controller.moveToNextDisplay(task.taskId)
+        with(getLatestWct(expectTransition = TRANSIT_CHANGE)) {
+            assertThat(hierarchyOps).hasSize(1)
+            assertThat(hierarchyOps[0].container).isEqualTo(task.token.asBinder())
+            assertThat(hierarchyOps[0].isReparent).isTrue()
+            assertThat(hierarchyOps[0].newParent).isEqualTo(secondDisplayArea.token.asBinder())
+            assertThat(hierarchyOps[0].toTop).isTrue()
+        }
+    }
+
+    @Test
+    fun moveToNextDisplay_moveFromSecondToFirstDisplay() {
+        // Set up two display ids
+        whenever(rootTaskDisplayAreaOrganizer.displayIds)
+            .thenReturn(intArrayOf(DEFAULT_DISPLAY, SECOND_DISPLAY))
+        // Create a mock for the target display area: default display
+        val defaultDisplayArea = DisplayAreaInfo(MockToken().token(), DEFAULT_DISPLAY, 0)
+        whenever(rootTaskDisplayAreaOrganizer.getDisplayAreaInfo(DEFAULT_DISPLAY))
+                .thenReturn(defaultDisplayArea)
+
+        val task = setUpFreeformTask(displayId = SECOND_DISPLAY)
+        controller.moveToNextDisplay(task.taskId)
+
+        with(getLatestWct(expectTransition = TRANSIT_CHANGE)) {
+            assertThat(hierarchyOps).hasSize(1)
+            assertThat(hierarchyOps[0].container).isEqualTo(task.token.asBinder())
+            assertThat(hierarchyOps[0].isReparent).isTrue()
+            assertThat(hierarchyOps[0].newParent).isEqualTo(defaultDisplayArea.token.asBinder())
+            assertThat(hierarchyOps[0].toTop).isTrue()
+        }
+    }
+
+    @Test
     fun getTaskWindowingMode() {
         val fullscreenTask = setUpFullscreenTask()
         val freeformTask = setUpFreeformTask()