Merge "Update launch root rule to consider candidate task if needed" into tm-dev

services/core/java/com/android/server/wm/Task.java

@@ -1724,8 +1724,8 @@ class Task extends TaskFragment {
     /** Returns {@code true} if this task is currently in split-screen. */
     boolean inSplitScreen() {
         return getWindowingMode() == WINDOWING_MODE_MULTI_WINDOW
-                && getRootTask() != null
+                && getCreatedByOrganizerTask() != null
-                && getRootTask().getAdjacentTaskFragment() != null;
+                && getCreatedByOrganizerTask().getAdjacentTaskFragment() != null;
     }
 
     private boolean supportsSplitScreenWindowingModeInner(@Nullable TaskDisplayArea tda) {

services/core/java/com/android/server/wm/TaskDisplayArea.java

@@ -963,7 +963,7 @@ final class TaskDisplayArea extends DisplayArea<WindowContainer> {
         } else if (candidateTask != null) {
             final int position = onTop ? POSITION_TOP : POSITION_BOTTOM;
             final Task launchRootTask = getLaunchRootTask(resolvedWindowingMode, activityType,
-                    options, sourceTask, launchFlags);
+                    options, sourceTask, launchFlags, candidateTask);
             if (launchRootTask != null) {
                 if (candidateTask.getParent() == null) {
                     launchRootTask.addChild(candidateTask, position);
@@ -1117,6 +1117,13 @@ final class TaskDisplayArea extends DisplayArea<WindowContainer> {
     @Nullable
     Task getLaunchRootTask(int windowingMode, int activityType, @Nullable ActivityOptions options,
             @Nullable Task sourceTask, int launchFlags) {
+        return getLaunchRootTask(windowingMode, activityType, options, sourceTask, launchFlags,
+                null /* candidateTask */);
+    }
+
+    @Nullable
+    Task getLaunchRootTask(int windowingMode, int activityType, @Nullable ActivityOptions options,
+            @Nullable Task sourceTask, int launchFlags, @Nullable Task candidateTask) {
         // Try to use the launch root task in options if available.
         if (options != null) {
             final Task launchRootTask = Task.fromWindowContainerToken(options.getLaunchRootTask());
@@ -1157,9 +1164,19 @@ final class TaskDisplayArea extends DisplayArea<WindowContainer> {
         }
 
         // For a better split UX, If a task is launching from a created-by-organizer task, it should
-        // be launched into the same created-by-organizer task as well.
+        // be launched into the same created-by-organizer task as well. Unless, the candidate task
-        if (sourceTask != null) {
+        // is already positioned in the split.
-            return sourceTask.getCreatedByOrganizerTask();
+        Task preferredRootInSplit = sourceTask != null && sourceTask.inSplitScreen()
+                ? sourceTask.getCreatedByOrganizerTask() : null;
+        if (preferredRootInSplit != null) {
+            if (candidateTask != null) {
+                final Task candidateRoot = candidateTask.getCreatedByOrganizerTask();
+                if (candidateRoot != null && candidateRoot != preferredRootInSplit
+                        && preferredRootInSplit == candidateRoot.getAdjacentTaskFragment()) {
+                    preferredRootInSplit = candidateRoot;
+                }
+            }
+            return preferredRootInSplit;
         }
 
         return null;

services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java

@@ -741,4 +741,35 @@ public class TaskDisplayAreaTests extends WindowTestsBase {
         assertEquals(isAssistantOnTop ? topPosition : topPosition - 4,
                 getTaskIndexOf(taskDisplayArea, assistRootTask));
     }
+
+    /**
+     * This test verifies proper launch root based on source and candidate task for split screen.
+     * If a task is launching from a created-by-organizer task, it should be launched into the
+     * same created-by-organizer task as well. Unless, the candidate task is already positioned in
+     * the split.
+     */
+    @Test
+    public void getLaunchRootTaskInSplit() {
+        final Task rootTask = createTask(
+                mDisplayContent, WINDOWING_MODE_MULTI_WINDOW, ACTIVITY_TYPE_STANDARD);
+        rootTask.mCreatedByOrganizer = true;
+        final Task adjacentRootTask = createTask(
+                mDisplayContent, WINDOWING_MODE_MULTI_WINDOW, ACTIVITY_TYPE_STANDARD);
+        adjacentRootTask.mCreatedByOrganizer = true;
+        final Task candidateTask = createTaskInRootTask(rootTask, 0 /* userId*/);
+        final TaskDisplayArea taskDisplayArea = rootTask.getDisplayArea();
+        adjacentRootTask.setAdjacentTaskFragment(rootTask, false /* moveTogether */);
+
+        // Verify the launch root with candidate task
+        Task actualRootTask = taskDisplayArea.getLaunchRootTask(WINDOWING_MODE_UNDEFINED,
+                ACTIVITY_TYPE_STANDARD, null /* options */, adjacentRootTask /* sourceTask */,
+                0 /* launchFlags */, candidateTask);
+        assertSame(rootTask, actualRootTask.getRootTask());
+
+        // Verify the launch root task without candidate task
+        actualRootTask = taskDisplayArea.getLaunchRootTask(WINDOWING_MODE_UNDEFINED,
+                ACTIVITY_TYPE_STANDARD, null /* options */, adjacentRootTask /* sourceTask */,
+                0 /* launchFlags */);
+        assertSame(adjacentRootTask, actualRootTask.getRootTask());
+    }
 }