Update recent tasks when task moves to top

When a task is moved to the top, ensure that the recents entry is moved
to the top at the same time.

Bug: 280468885
Test: atest WmTests:RecentTasksTest
Change-Id: I780893fd0dc05cb85e9d8473c1feb089593d9793

services/core/java/com/android/server/wm/RecentTasks.java

@@ -1104,6 +1104,10 @@ class RecentTasks {
                         // front unless overridden by the provided activity options
                         mTasks.remove(taskIndex);
                         mTasks.add(0, task);
+                        if (taskIndex != 0) {
+                            // Only notify when position changes
+                            mTaskNotificationController.notifyTaskListUpdated();
+                        }
 
                         if (DEBUG_RECENTS) {
                             Slog.d(TAG_RECENTS, "addRecent: moving to top " + task
@@ -1552,7 +1556,7 @@ class RecentTasks {
                         task.affinity != null && task.affinity.equals(t.affinity);
                 final boolean sameIntent = intent != null && intent.filterEquals(trIntent);
                 boolean multiTasksAllowed = false;
-                final int flags = intent.getFlags();
+                final int flags = intent != null ? intent.getFlags() : 0;
                 if ((flags & (FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_NEW_DOCUMENT)) != 0
                         && (flags & FLAG_ACTIVITY_MULTIPLE_TASK) != 0) {
                     multiTasksAllowed = true;

services/core/java/com/android/server/wm/Task.java

@@ -1271,6 +1271,10 @@ class Task extends TaskFragment {
         if (isPersistable) {
             mLastTimeMoved = System.currentTimeMillis();
         }
+        if (toTop && inRecents) {
+            // If task is in recents, ensure it is at the top
+            mTaskSupervisor.mRecentTasks.add(this);
+        }
     }
 
     // Close up recents linked list.

services/tests/wmtests/src/com/android/server/wm/ActivityStarterTests.java

@@ -1702,6 +1702,9 @@ public class ActivityStarterTests extends WindowTestsBase {
 
     @Test
     public void testRecordActivityMovementBeforeDeliverToTop() {
+        // Mock recents as task is only marked to be in recents
+        mAtm.mTaskSupervisor.setRecentTasks(mock(RecentTasks.class));
+
         final Task task = new TaskBuilder(mAtm.mTaskSupervisor).build();
         final ActivityRecord activityBot = new ActivityBuilder(mAtm).setTask(task).build();
         final ActivityRecord activityTop = new ActivityBuilder(mAtm).setTask(task).build();

services/tests/wmtests/src/com/android/server/wm/RecentTasksTest.java

@@ -49,10 +49,12 @@ import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
 
 import static java.lang.Integer.MAX_VALUE;
 
@@ -1138,6 +1140,40 @@ public class RecentTasksTest extends WindowTestsBase {
         verify(controller, times(2)).notifyTaskListUpdated();
     }
 
+    @Test
+    public void addTask_taskAlreadyInRecentsMovedToTop_callsTaskNotificationController() {
+        final Task firstTask = createTaskBuilder(".Task").build();
+        final Task secondTask = createTaskBuilder(".Task2").build();
+
+        mRecentTasks.add(firstTask);
+        mRecentTasks.add(secondTask);
+
+        TaskChangeNotificationController controller =
+                mAtm.getTaskChangeNotificationController();
+        clearInvocations(controller);
+
+        // Add firstTask back to top
+        mRecentTasks.add(firstTask);
+        verify(controller).notifyTaskListUpdated();
+    }
+
+    @Test
+    public void addTask_taskAlreadyInRecentsOnTop_doesNotNotify() {
+        final Task firstTask = createTaskBuilder(".Task").build();
+        final Task secondTask = createTaskBuilder(".Task2").build();
+
+        mRecentTasks.add(firstTask);
+        mRecentTasks.add(secondTask);
+
+        TaskChangeNotificationController controller =
+                mAtm.getTaskChangeNotificationController();
+        clearInvocations(controller);
+
+        // Add secondTask to top again
+        mRecentTasks.add(secondTask);
+        verifyZeroInteractions(controller);
+    }
+
     @Test
     public void removeTask_callsTaskNotificationController() {
         final Task task = createTaskBuilder(".Task").build();