From 41a13b7136979de6732d106e1d53337566a84b6e Mon Sep 17 00:00:00 2001
From: Arthur Hung <arthurhung@google.com>
Date: Thu, 28 Apr 2022 04:52:44 +0000
Subject: [PATCH] Fix back gesture send to wrong focus window

Ensure we could get the proper focused window token what it's during
updating the focus if user touched down on another non-focused window.

It also called `startBackNavigation` when received first move that next
to down event to ensure the `WMS.onPointerDownOutsideFocus` could be
processed first.

Test: atest BackAnimationControllerTest BackNavigationControllerTests
Test: enabled split-screen, trigger back gesture on non-focused window
Bug: 230442550
Bug: 227724016
Change-Id: I81c4f02d43299c03f94dc295bb23ba80d46bded8
---
 .../android/wm/shell/back/BackAnimationController.java | 10 +++++++---
 .../wm/shell/back/BackAnimationControllerTest.java     |  5 ++---
 .../android/server/wm/BackNavigationController.java    |  9 +--------
 .../server/wm/BackNavigationControllerTests.java       |  1 +
 4 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
index ced36a705df27..af9317ab6dcc3 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
@@ -206,9 +206,13 @@ public class BackAnimationController implements RemoteCallable<BackAnimationCont
      * {@link BackAnimationController}
      */
     public void onMotionEvent(MotionEvent event, int action, @BackEvent.SwipeEdge int swipeEdge) {
-        if (action == MotionEvent.ACTION_DOWN) {
-            initAnimation(event);
-        } else if (action == MotionEvent.ACTION_MOVE) {
+        if (action == MotionEvent.ACTION_MOVE) {
+            if (!mBackGestureStarted) {
+                // Let the animation initialized here to make sure the onPointerDownOutsideFocus
+                // could be happened when ACTION_DOWN, it may change the current focus that we
+                // would access it when startBackNavigation.
+                initAnimation(event);
+            }
             onMove(event, swipeEdge);
         } else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
             ProtoLog.d(WM_SHELL_BACK_PREVIEW,
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/back/BackAnimationControllerTest.java b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/back/BackAnimationControllerTest.java
index a905dcaebc6b8..1ce2444281d4a 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/back/BackAnimationControllerTest.java
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/back/BackAnimationControllerTest.java
@@ -198,18 +198,17 @@ public class BackAnimationControllerTest {
         createNavigationInfo(animationTarget, null, null,
                 BackNavigationInfo.TYPE_RETURN_TO_HOME);
 
-        // Check that back start is dispatched.
         mController.onMotionEvent(
                 MotionEvent.obtain(0, 0, MotionEvent.ACTION_DOWN, 0, 0, 0),
                 MotionEvent.ACTION_DOWN,
                 BackEvent.EDGE_LEFT);
-        verify(mIOnBackInvokedCallback).onBackStarted();
 
-        // Check that back progress is dispatched.
+        // Check that back start and progress is dispatched when first move.
         mController.onMotionEvent(
                 MotionEvent.obtain(10, 0, MotionEvent.ACTION_MOVE, 100, 100, 0),
                 MotionEvent.ACTION_MOVE,
                 BackEvent.EDGE_LEFT);
+        verify(mIOnBackInvokedCallback).onBackStarted();
         ArgumentCaptor<BackEvent> backEventCaptor = ArgumentCaptor.forClass(BackEvent.class);
         verify(mIOnBackInvokedCallback).onBackProgressed(backEventCaptor.capture());
         assertEquals(animationTarget, backEventCaptor.getValue().getDepartingAnimationTarget());
diff --git a/services/core/java/com/android/server/wm/BackNavigationController.java b/services/core/java/com/android/server/wm/BackNavigationController.java
index b37f980ce9a01..aaae82d07976e 100644
--- a/services/core/java/com/android/server/wm/BackNavigationController.java
+++ b/services/core/java/com/android/server/wm/BackNavigationController.java
@@ -124,8 +124,7 @@ class BackNavigationController {
                     LocalServices.getService(WindowManagerInternal.class);
             IBinder focusedWindowToken = windowManagerInternal.getFocusedWindowToken();
 
-            window = wmService.windowForClientLocked(null, focusedWindowToken,
-                    false /* throwOnError */);
+            window = wmService.getFocusedWindowLocked();
 
             if (window == null) {
                 EmbeddedWindowController.EmbeddedWindow embeddedWindow =
@@ -146,12 +145,6 @@ class BackNavigationController {
                         "Focused window found using getFocusedWindowToken");
             }
 
-            if (window == null) {
-                window = wmService.getFocusedWindowLocked();
-                ProtoLog.d(WM_DEBUG_BACK_PREVIEW,
-                        "Focused window found using wmService.getFocusedWindowLocked()");
-            }
-
             if (window == null) {
                 // We don't have any focused window, fallback ont the top currentTask of the focused
                 // display.
diff --git a/services/tests/wmtests/src/com/android/server/wm/BackNavigationControllerTests.java b/services/tests/wmtests/src/com/android/server/wm/BackNavigationControllerTests.java
index 49cd343ef4af8..873d9f3fc023e 100644
--- a/services/tests/wmtests/src/com/android/server/wm/BackNavigationControllerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/BackNavigationControllerTests.java
@@ -306,6 +306,7 @@ public class BackNavigationControllerTests extends WindowTestsBase {
         if (focus) {
             doReturn(window.getWindowInfo().token)
                     .when(mWindowManagerInternal).getFocusedWindowToken();
+            doReturn(window).when(mWm).getFocusedWindowLocked();
         }
     }
 }