Skip handling recents toggle if a task is locked.

- When a task is locked, the logic will still try to start the recents
  activity (but will fail since it's a lock mode violation).  Nothing
  resets the state, so the button will stop responding.  Instead, skip
  handling of the button until the user unlocks the task.  Also add a
  final fallback for resetting the waiting state, whenever an app
  transition completes.

Bug: 65059121
Test: Launch app after pinning app, tap the recents button, and then
      un-pin and try to re-enter recents.

Change-Id: I0215957f041241b5a61d7fd5b784410368bbd996

packages/SystemUI/src/com/android/systemui/recents/Recents.java

@@ -565,6 +565,13 @@ public class Recents extends SystemUI
         mImpl.showPrevAffiliatedTask();
     }
 
+    @Override
+    public void appTransitionFinished() {
+        // Fallback, reset the flag once an app transition ends
+        EventBus.getDefault().send(new SetWaitingForTransitionStartEvent(
+                false /* waitingForTransitionStart */));
+    }
+
     /**
      * Updates on configuration change.
      */

packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java

@@ -376,6 +376,12 @@ public class RecentsImpl implements ActivityOptions.OnAnimationFinishedListener
     }
 
     public void toggleRecents(int growTarget) {
+        // Skip preloading if the task is locked
+        SystemServicesProxy ssp = Recents.getSystemServices();
+        if (ssp.isScreenPinningActive()) {
+            return;
+        }
+
         // Skip this toggle if we are already waiting to trigger recents via alt-tab
         if (mFastAltTabTrigger.isDozing()) {
             return;
@@ -391,7 +397,6 @@ public class RecentsImpl implements ActivityOptions.OnAnimationFinishedListener
         mTriggeredFromAltTab = false;
 
         try {
-            SystemServicesProxy ssp = Recents.getSystemServices();
             MutableBoolean isHomeStackVisible = new MutableBoolean(true);
             long elapsedTime = SystemClock.elapsedRealtime() - mLastToggleTime;
 
@@ -454,11 +459,16 @@ public class RecentsImpl implements ActivityOptions.OnAnimationFinishedListener
     }
 
     public void preloadRecents() {
+        // Skip preloading if the task is locked
+        SystemServicesProxy ssp = Recents.getSystemServices();
+        if (ssp.isScreenPinningActive()) {
+            return;
+        }
+
         // Preload only the raw task list into a new load plan (which will be consumed by the
         // RecentsActivity) only if there is a task to animate to.  Post this to ensure that we
         // don't block the touch feedback on the nav bar button which triggers this.
         mHandler.post(() -> {
-            SystemServicesProxy ssp = Recents.getSystemServices();
             MutableBoolean isHomeStackVisible = new MutableBoolean(true);
             if (!ssp.isRecentsActivityVisible(isHomeStackVisible)) {
                 ActivityManager.RunningTaskInfo runningTask = ssp.getRunningTask();