From 7965f957e752737c31bae6d9e0c6f1ee3ff80496 Mon Sep 17 00:00:00 2001
From: HQ Liu <hql@google.com>
Date: Wed, 4 May 2022 09:50:03 -0700
Subject: [PATCH] Prevent to revoke input focus from
 recentsAnimationInputConsumer

During recents animation, there are increasing number of ANR, that is
because the input focus is suppose to be on the
recents_animation_input_consumer, but the focus is revoked falsely.

To fix the issue, stop sending requet to remove focus when the focus is
on the input consumer.

Bug: 222232784
Bug: 223750399
Test: manual
Change-Id: Id19d64d8027a07dc9a1236d10b9e1185ebc717c4
---
 core/jni/android_view_SurfaceControl.cpp         |  1 +
 .../java/com/android/server/wm/InputMonitor.java | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/core/jni/android_view_SurfaceControl.cpp b/core/jni/android_view_SurfaceControl.cpp
index c769da57eecc4..4044c579a57fd 100644
--- a/core/jni/android_view_SurfaceControl.cpp
+++ b/core/jni/android_view_SurfaceControl.cpp
@@ -1921,6 +1921,7 @@ static void nativeRemoveCurrentInputFocus(JNIEnv* env, jclass clazz, jlong trans
     FocusRequest request;
     request.timestamp = systemTime(SYSTEM_TIME_MONOTONIC);
     request.displayId = displayId;
+    request.windowName = "<null>";
     transaction->setFocusedWindow(request);
 }
 
diff --git a/services/core/java/com/android/server/wm/InputMonitor.java b/services/core/java/com/android/server/wm/InputMonitor.java
index 65062e576d550..1ddd0b2e2c957 100644
--- a/services/core/java/com/android/server/wm/InputMonitor.java
+++ b/services/core/java/com/android/server/wm/InputMonitor.java
@@ -416,8 +416,22 @@ final class InputMonitor {
 
         final IBinder focusToken = focus != null ? focus.mInputChannelToken : null;
         if (focusToken == null) {
+            if (recentsAnimationInputConsumer != null
+                    && recentsAnimationInputConsumer.mWindowHandle != null
+                    && mInputFocus == recentsAnimationInputConsumer.mWindowHandle.token) {
+                // Avoid removing input focus from recentsAnimationInputConsumer.
+                // When the recents animation input consumer has the input focus,
+                // mInputFocus does not match to mDisplayContent.mCurrentFocus. Making it to be
+                // a special case, that do not remove the input focus from it when
+                // mDisplayContent.mCurrentFocus is null. This special case should be removed
+                // once recentAnimationInputConsumer is removed.
+                return;
+            }
             // When an app is focused, but its window is not showing yet, remove the input focus
-            // from the current window.
+            // from the current window. This enforces the input focus to match
+            // mDisplayContent.mCurrentFocus. However, if more special cases are discovered that
+            // the input focus and mDisplayContent.mCurrentFocus are expected to mismatch,
+            // the whole logic of how and when to revoke focus needs to be checked.
             if (mDisplayContent.mFocusedApp != null && mInputFocus != null) {
                 ProtoLog.v(WM_DEBUG_FOCUS_LIGHT, "App %s is focused,"
                         + " but the window is not ready. Start a transaction to remove focus from"