Merge "Don't keep visible windows in pinned stack on screen when app dies"

3 files changed, 30 insertions, 1 deletions

diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index 6307477aa766..420bf31a189d 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -608,6 +608,14 @@ public class ActivityManager {
         public static boolean resizeStackWithLaunchBounds(int stackId) {
             return stackId == PINNED_STACK_ID;
         }
+
+        /**
+         * Returns true if any visible windows belonging to apps in this stack should be kept on
+         * screen when the app is killed due to something like the low memory killer.
+         */
+        public static boolean keepVisibleDeadAppWindowOnScreen(int stackId) {
+            return stackId != PINNED_STACK_ID;
+        }
     }
 
     /**
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 1021411084c3..5adf6278dd9d 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -2193,7 +2193,7 @@ public class WindowManagerService extends IWindowManager.Stub
             // need to see about starting one.
             wasVisible = win.isWinVisibleLw();
 
-            if (wasVisible && appToken != null && appToken.appDied) {
+            if (win.shouldKeepVisibleDeadAppWindow()) {
                 if (DEBUG_ADD_REMOVE) Slog.v(TAG_WM,
                         "Not removing " + win + " because app died while it's visible");
 
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index dca7735f02fc..e8de90c93f0a 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -1615,6 +1615,27 @@ final class WindowState implements WindowManagerPolicy.WindowState {
         }
     }
 
+    /**
+     * Returns true if this window is visible and belongs to a dead app and shouldn't be removed,
+     * because we want to preserve its location on screen to be re-activated later when the user
+     * interacts with it.
+     */
+    boolean shouldKeepVisibleDeadAppWindow() {
+        if (!isWinVisibleLw() || mAppToken == null || !mAppToken.appDied) {
+            // Not a visible app window or the app isn't dead.
+            return false;
+        }
+
+        if (mAttrs.type == TYPE_APPLICATION_STARTING) {
+            // We don't keep starting windows since they were added by the window manager before
+            // the app even launched.
+            return false;
+        }
+
+        final TaskStack stack = getStack();
+        return stack != null && StackId.keepVisibleDeadAppWindowOnScreen(stack.mStackId);
+    }
+
     /** @return true if this window desires key events. */
     boolean canReceiveKeys() {
         return isVisibleOrAdding()