Fixes some issues for embedded Task

1. Don't compute minimum dimensions for embeddedTask in TaskFragment
2. Consider TaskFragment containing ActivityRecord and embedded Task in
   Task#getTopResumed(Pausing)Activity
3. Add support to start Activity on top of existing embedded Task in
   TaskFragment

Test: SplitActivityLifecycleTest
Bug: 192442647

Change-Id: I8c0988e5070053c6a3b336184aa0a9ebd79adfda

3 files changed, 64 insertions, 25 deletions

diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index 3b43e48a53af..d1f50f3e5b78 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -2778,7 +2778,9 @@ class ActivityStarter {
             // request. If the task was resolved and different than mInTaskFragment, reparent the
             // task to mInTaskFragment for embedding.
             if (mInTaskFragment.getTask() != task) {
-                task.reparent(mInTaskFragment, POSITION_TOP);
+                if (shouldReparentInTaskFragment(task)) {
+                    task.reparent(mInTaskFragment, POSITION_TOP);
+                }
             } else {
                 newParent = mInTaskFragment;
             }
@@ -2797,6 +2799,18 @@ class ActivityStarter {
         }
     }
 
+    private boolean shouldReparentInTaskFragment(Task task) {
+        // The task has not been embedded. We should reparent the task to TaskFragment.
+        if (!task.isEmbedded()) {
+            return true;
+        }
+        WindowContainer<?> parent = task.getParent();
+        // If the Activity is going to launch on top of embedded Task in the same TaskFragment,
+        // we don't need to reparent the Task. Otherwise, the embedded Task should reparent to
+        // another TaskFragment.
+        return parent.asTaskFragment() != mInTaskFragment;
+    }
+
     private int adjustLaunchFlagsToDocumentMode(ActivityRecord r, boolean launchSingleInstance,
             boolean launchSingleTask, int launchFlags) {
         if ((launchFlags & Intent.FLAG_ACTIVITY_NEW_DOCUMENT) != 0 &&
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index 424a5aa98afd..ef3065e2f1e8 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -1226,7 +1226,7 @@ class Task extends TaskFragment {
         mRootWindowContainer.updateUIDsPresentOnDisplay();
     }
 
-    /** Returns the currently topmost resumed activity. */
+    @Override
     @Nullable
     ActivityRecord getTopResumedActivity() {
         if (!isLeafTask()) {
@@ -1243,15 +1243,7 @@ class Task extends TaskFragment {
         for (int i = mChildren.size() - 1; i >= 0; --i) {
             final WindowContainer child = mChildren.get(i);
             if (child.asTaskFragment() != null) {
-                final ActivityRecord[] resumedActivity = new ActivityRecord[1];
-                child.asTaskFragment().forAllLeafTaskFragments(fragment -> {
-                    if (fragment.getResumedActivity() != null) {
-                        resumedActivity[0] = fragment.getResumedActivity();
-                        return true;
-                    }
-                    return false;
-                });
-                topResumedActivity = resumedActivity[0];
+                topResumedActivity = child.asTaskFragment().getTopResumedActivity();
             } else if (taskResumedActivity != null
                     && child.asActivityRecord() == taskResumedActivity) {
                 topResumedActivity = taskResumedActivity;
@@ -1263,9 +1255,7 @@ class Task extends TaskFragment {
         return null;
     }
 
-    /**
-     * Returns the currently topmost pausing activity.
-     */
+    @Override
     @Nullable
     ActivityRecord getTopPausingActivity() {
         if (!isLeafTask()) {
@@ -1282,15 +1272,7 @@ class Task extends TaskFragment {
         for (int i = mChildren.size() - 1; i >= 0; --i) {
             final WindowContainer child = mChildren.get(i);
             if (child.asTaskFragment() != null) {
-                final ActivityRecord[] pausingActivity = new ActivityRecord[1];
-                child.asTaskFragment().forAllLeafTaskFragments(fragment -> {
-                    if (fragment.getPausingActivity() != null) {
-                        pausingActivity[0] = fragment.getPausingActivity();
-                        return true;
-                    }
-                    return false;
-                });
-                topPausingActivity = pausingActivity[0];
+                topPausingActivity = child.asTaskFragment().getTopPausingActivity();
             } else if (taskPausingActivity != null
                     && child.asActivityRecord() == taskPausingActivity) {
                 topPausingActivity = taskPausingActivity;
diff --git a/services/core/java/com/android/server/wm/TaskFragment.java b/services/core/java/com/android/server/wm/TaskFragment.java
index ca1d83e2bd15..3cebd739d3ee 100644
--- a/services/core/java/com/android/server/wm/TaskFragment.java
+++ b/services/core/java/com/android/server/wm/TaskFragment.java
@@ -352,7 +352,29 @@ class TaskFragment extends WindowContainer<WindowContainer> {
         return mAdjacentTaskFragment;
     }
 
-    /** @return the currently resumed activity. */
+    /** Returns the currently topmost resumed activity. */
+    @Nullable
+    ActivityRecord getTopResumedActivity() {
+        final ActivityRecord taskFragResumedActivity = getResumedActivity();
+        for (int i = getChildCount() - 1; i >= 0; --i) {
+            WindowContainer<?> child = getChildAt(i);
+            ActivityRecord topResumedActivity = null;
+            if (taskFragResumedActivity != null && child == taskFragResumedActivity) {
+                topResumedActivity = child.asActivityRecord();
+            } else if (child.asTaskFragment() != null) {
+                topResumedActivity = child.asTaskFragment().getTopResumedActivity();
+            }
+            if (topResumedActivity != null) {
+                return topResumedActivity;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the currently resumed activity in this TaskFragment's
+     * {@link #mChildren direct children}
+     */
     ActivityRecord getResumedActivity() {
         return mResumedActivity;
     }
@@ -376,6 +398,25 @@ class TaskFragment extends WindowContainer<WindowContainer> {
         mPausingActivity = pausing;
     }
 
+    /** Returns the currently topmost pausing activity. */
+    @Nullable
+    ActivityRecord getTopPausingActivity() {
+        final ActivityRecord taskFragPausingActivity = getPausingActivity();
+        for (int i = getChildCount() - 1; i >= 0; --i) {
+            WindowContainer<?> child = getChildAt(i);
+            ActivityRecord topPausingActivity = null;
+            if (taskFragPausingActivity != null && child == taskFragPausingActivity) {
+                topPausingActivity = child.asActivityRecord();
+            } else if (child.asTaskFragment() != null) {
+                topPausingActivity = child.asTaskFragment().getTopPausingActivity();
+            }
+            if (topPausingActivity != null) {
+                return topPausingActivity;
+            }
+        }
+        return null;
+    }
+
     ActivityRecord getPausingActivity() {
         return mPausingActivity;
     }
@@ -1673,7 +1714,9 @@ class TaskFragment extends WindowContainer<WindowContainer> {
         }
 
         final Task thisTask = asTask();
-        if (thisTask != null) {
+        // Embedded Task's configuration should go with parent TaskFragment, so we don't re-compute
+        // configuration here.
+        if (thisTask != null && !thisTask.isEmbedded()) {
             thisTask.resolveLeafTaskOnlyOverrideConfigs(newParentConfig,
                     mTmpBounds /* previousBounds */);
         }