From 20f55b10b2e57c1972073db42676ccfd8027f0aa Mon Sep 17 00:00:00 2001
From: Louis Chang <louischang@google.com>
Date: Mon, 26 Jul 2021 17:48:00 +0800
Subject: [PATCH] Supporting independent back nav while task embedded

Also directly setting the focused app if there is a task
embedded in the split.

Bug: 189385926
Test: navigate independently
Change-Id: I0fb36a4bcc6245af26f114f96862e1cb498d146d
---
 .../server/wm/ActivityTaskManagerService.java  | 18 +++++++++---------
 .../com/android/server/wm/DisplayContent.java  | 17 +++++++++++++----
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 83c83e7b5f391..081c618b62aa7 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -1909,15 +1909,15 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
 
         if (r.moveFocusableActivityToTop("setFocusedTask")) {
             mRootWindowContainer.resumeFocusedTasksTopActivities();
-        } else if (touchedActivity != null && touchedActivity != r
-                && touchedActivity.getTask() == r.getTask()
-                && touchedActivity.getTaskFragment() != r.getTaskFragment()) {
-            // Set the focused app directly since the focused window is not on the
-            // top-most TaskFragment of the top-most Task
-            final DisplayContent displayContent = touchedActivity.getDisplayContent();
-            displayContent.setFocusedApp(touchedActivity);
-            mWindowManager.updateFocusedWindowLocked(UPDATE_FOCUS_NORMAL,
-                    true /* updateInputWindows */);
+        } else if (touchedActivity != null && touchedActivity.isFocusable()) {
+            final TaskFragment parent = touchedActivity.getTaskFragment();
+            if (parent != null && parent.isEmbedded()) {
+                // Set the focused app directly if the focused window is currently embedded
+                final DisplayContent displayContent = touchedActivity.getDisplayContent();
+                displayContent.setFocusedApp(touchedActivity);
+                mWindowManager.updateFocusedWindowLocked(UPDATE_FOCUS_NORMAL,
+                        true /* updateInputWindows */);
+            }
         }
     }
 
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 708b7ff73ea6e..dbd9eeb7ac48a 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -777,10 +777,19 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
                 return true;
             }
 
-            if (focusedApp.getTask() == activity.getTask()
-                    && focusedApp.getTaskFragment() != activity.getTaskFragment()) {
-                // Do not use the activity window of another TaskFragment in the same leaf Task
-                return false;
+            // If the candidate activity is currently being embedded in the focused task, the
+            // activity cannot be focused unless it is on the same TaskFragment as the focusedApp's.
+            TaskFragment parent = activity.getTaskFragment();
+            if (parent != null && parent.isEmbedded()) {
+                Task hostTask = focusedApp.getTask();
+                if (hostTask.isEmbedded()) {
+                    // Use the hosting task if the current task is embedded.
+                    hostTask = hostTask.getParent().asTaskFragment().getTask();
+                }
+                if (activity.isDescendantOf(hostTask)
+                        && activity.getTaskFragment() != focusedApp.getTaskFragment()) {
+                    return false;
+                }
             }
         }