Add a listener when task snapshots change

Since we start recents before we take the snapshot, we need to add
a mechanism to inform recents about task snapshots changes.

We add a new method to TaskStackChangedListener,
onTaskSnapshotChanged, which gets called whenever a task snapshot
changes. Then, SystemUI registers such a listener and updates the
task thumbnail view for the specific task.

Test: Open app, press recents, make sure thumbnail is up-to-date
Bug: 31339431
Change-Id: I01e81b9cd11886da734da671c68d5732aa51009f

3 files changed, 11 insertions, 1 deletions

diff --git a/core/java/android/app/IActivityManager.aidl b/core/java/android/app/IActivityManager.aidl
index 21ae853918f6..5824c32e6f2e 100644
--- a/core/java/android/app/IActivityManager.aidl
+++ b/core/java/android/app/IActivityManager.aidl
@@ -31,7 +31,6 @@ import android.app.IStopUserCallback;
 import android.app.ITaskStackListener;
 import android.app.IUiAutomationConnection;
 import android.app.IUidObserver;
-
 import android.app.IUserSwitchObserver;
 import android.app.Notification;
 import android.app.PendingIntent;
diff --git a/core/java/android/app/ITaskStackListener.aidl b/core/java/android/app/ITaskStackListener.aidl
index ef997c90166e..6deedb6f5278 100644
--- a/core/java/android/app/ITaskStackListener.aidl
+++ b/core/java/android/app/ITaskStackListener.aidl
@@ -102,4 +102,9 @@ oneway interface ITaskStackListener {
      * been locked.
      */
     void onTaskProfileLocked(int taskId, int userId);
+
+    /**
+     * Called when a task snapshot got updated.
+     */
+    void onTaskSnapshotChanged(int taskId, in ActivityManager.TaskSnapshot snapshot);
 }
diff --git a/core/java/android/app/TaskStackListener.java b/core/java/android/app/TaskStackListener.java
index ad5e69b5cbd4..fd766bfbff21 100644
--- a/core/java/android/app/TaskStackListener.java
+++ b/core/java/android/app/TaskStackListener.java
@@ -16,6 +16,7 @@
 
 package android.app;
 
+import android.app.ActivityManager.TaskSnapshot;
 import android.content.ComponentName;
 import android.os.RemoteException;
 
@@ -78,4 +79,9 @@ public abstract class TaskStackListener extends ITaskStackListener.Stub {
     @Override
     public void onTaskProfileLocked(int taskId, int userId) {
     }
+
+    @Override
+    public void onTaskSnapshotChanged(int taskId, TaskSnapshot snapshot)
+            throws RemoteException {
+    }
 }