Clear routes when media router manager has no callback

This CL clears routes when the last callback of MediaRouter2Manager
is unregistered. By doing this, we can ensure
MediaRouter2Manager#getAvailableRoutes() returns correct routes
during at least a single callback is registered.

A test for the behavior is added as well.

This CL also fixed a bug that unregistering a callback from MediaRouter2
disconnects it when multiple callback is used.

Bug: 153515567
Test: atest mediaroutertest & cts test & manually
 using MediaRouter2Demo and Sample OutputSwitcher to see
 if forgotten BT device is correctly removed.
 (w/o this CL forgotten BT device remains)
Change-Id: I31a5001115f1f163c8971bbd906516551b860252

2 files changed, 52 insertions, 4 deletions

diff --git a/media/tests/MediaRouter/src/com/android/mediaroutertest/MediaRouter2ManagerTest.java b/media/tests/MediaRouter/src/com/android/mediaroutertest/MediaRouter2ManagerTest.java
index 6ca564fb34cc..207534b36f95 100644
--- a/media/tests/MediaRouter/src/com/android/mediaroutertest/MediaRouter2ManagerTest.java
+++ b/media/tests/MediaRouter/src/com/android/mediaroutertest/MediaRouter2ManagerTest.java
@@ -36,6 +36,7 @@ import static com.android.mediaroutertest.StubMediaRoute2ProviderService.VOLUME_
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import android.content.Context;
@@ -160,6 +161,7 @@ public class MediaRouter2ManagerTest {
         });
 
         MediaRoute2Info routeToRemove = routes.get(ROUTE_ID2);
+        assertNotNull(routeToRemove);
 
         StubMediaRoute2ProviderService sInstance =
                 StubMediaRoute2ProviderService.getInstance();
@@ -171,6 +173,52 @@ public class MediaRouter2ManagerTest {
         assertTrue(addedLatch.await(TIMEOUT_MS, TimeUnit.MILLISECONDS));
     }
 
+    @Test
+    public void testGetRoutes_removedRoute_returnsCorrectRoutes() throws Exception {
+        CountDownLatch addedLatch = new CountDownLatch(1);
+        CountDownLatch removedLatch = new CountDownLatch(1);
+
+        RouteCallback routeCallback = new RouteCallback() {
+            // Used to ensure the removed route is added.
+            @Override
+            public void onRoutesAdded(List<MediaRoute2Info> routes) {
+                if (removedLatch.getCount() > 0) {
+                    return;
+                }
+                addedLatch.countDown();
+            }
+
+            @Override
+            public void onRoutesRemoved(List<MediaRoute2Info> routes) {
+                removedLatch.countDown();
+            }
+        };
+
+        mRouter2.registerRouteCallback(mExecutor, routeCallback,
+                new RouteDiscoveryPreference.Builder(FEATURES_ALL, true).build());
+        mRouteCallbacks.add(routeCallback);
+
+        Map<String, MediaRoute2Info> routes = waitAndGetRoutesWithManager(FEATURES_ALL);
+        MediaRoute2Info routeToRemove = routes.get(ROUTE_ID2);
+        assertNotNull(routeToRemove);
+
+        StubMediaRoute2ProviderService sInstance =
+                StubMediaRoute2ProviderService.getInstance();
+        assertNotNull(sInstance);
+        sInstance.removeRoute(ROUTE_ID2);
+
+        // Wait until the route is removed.
+        assertTrue(removedLatch.await(TIMEOUT_MS, TimeUnit.MILLISECONDS));
+
+        Map<String, MediaRoute2Info> newRoutes = waitAndGetRoutesWithManager(FEATURES_ALL);
+        assertNull(newRoutes.get(ROUTE_ID2));
+
+        // Revert the removal.
+        sInstance.addRoute(routeToRemove);
+        assertTrue(addedLatch.await(TIMEOUT_MS, TimeUnit.MILLISECONDS));
+        mRouter2.unregisterRouteCallback(routeCallback);
+    }
+
     /**
      * Tests if we get proper routes for application that has special route feature.
      */
@@ -475,8 +523,8 @@ public class MediaRouter2ManagerTest {
         MediaRouter2Manager.Callback managerCallback = new MediaRouter2Manager.Callback() {
             @Override
             public void onRoutesAdded(List<MediaRoute2Info> routes) {
-                for (int i = 0; i < routes.size(); i++) {
-                    if (!routes.get(i).isSystemRoute()) {
+                for (MediaRoute2Info route : routes) {
+                    if (!route.isSystemRoute()) {
                         addedLatch.countDown();
                         break;
                     }
diff --git a/media/tests/MediaRouter/src/com/android/mediaroutertest/StubMediaRoute2ProviderService.java b/media/tests/MediaRouter/src/com/android/mediaroutertest/StubMediaRoute2ProviderService.java
index 6d46ba582ddc..4e398f26366a 100644
--- a/media/tests/MediaRouter/src/com/android/mediaroutertest/StubMediaRoute2ProviderService.java
+++ b/media/tests/MediaRouter/src/com/android/mediaroutertest/StubMediaRoute2ProviderService.java
@@ -65,9 +65,9 @@ public class StubMediaRoute2ProviderService extends MediaRoute2ProviderService {
     public static final String ROUTE_NAME_VARIABLE_VOLUME = "Variable Volume Route";
 
     public static final String FEATURE_SAMPLE =
-            "com.android.mediarouteprovider.FEATURE_SAMPLE";
+            "com.android.mediaroutertest.FEATURE_SAMPLE";
     public static final String FEATURE_SPECIAL =
-            "com.android.mediarouteprovider.FEATURE_SPECIAL";
+            "com.android.mediaroutertest..FEATURE_SPECIAL";
 
     Map<String, MediaRoute2Info> mRoutes = new HashMap<>();
     Map<String, String> mRouteIdToSessionId = new HashMap<>();