[Output Switcher] Fix list order for preference

Add system route to the top even Preference been set.
add check for isScanning to prevent exception

Bug: 286593457
Bug: 260055330
Test: make -j64 RunSettingsLibRoboTests ROBOTEST_FILTER="com.android.settingslib.media.InfoMediaManagerTest"
Change-Id: Ic7245f9c4169eabf63aa8eabac9b6a57fbc4ea7b

packages/SettingsLib/src/com/android/settingslib/media/InfoMediaManager.java

@@ -71,6 +71,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 
 /** InfoMediaManager provide interface to get InfoMediaDevice list. */
 @RequiresApi(Build.VERSION_CODES.R)
@@ -719,20 +720,19 @@ public abstract class InfoMediaManager extends MediaManager {
                 List<MediaRoute2Info> selectedRouteInfos, List<MediaRoute2Info> infolist,
                 List<RouteListingPreference.Item> preferenceRouteListing) {
             final List<MediaRoute2Info> sortedInfoList = new ArrayList<>(selectedRouteInfos);
+            infolist.removeAll(selectedRouteInfos);
+            sortedInfoList.addAll(infolist.stream().filter(
+                    MediaRoute2Info::isSystemRoute).collect(Collectors.toList()));
             for (RouteListingPreference.Item item : preferenceRouteListing) {
                 for (MediaRoute2Info info : infolist) {
                     if (item.getRouteId().equals(info.getId())
-                            && !selectedRouteInfos.contains(info)) {
+                            && !selectedRouteInfos.contains(info)
+                            && !info.isSystemRoute()) {
                         sortedInfoList.add(info);
                         break;
                     }
                 }
             }
-            if (sortedInfoList.size() != infolist.size()) {
-                infolist.removeAll(sortedInfoList);
-                sortedInfoList.addAll(infolist.stream().filter(
-                        MediaRoute2Info::isSystemRoute).toList());
-            }
             return sortedInfoList;
         }
 

packages/SettingsLib/src/com/android/settingslib/media/ManagerInfoMediaManager.java

@@ -43,6 +43,7 @@ public class ManagerInfoMediaManager extends InfoMediaManager {
     /* package */ final RouterManagerCallback mMediaRouterCallback = new RouterManagerCallback();
     @VisibleForTesting
     /* package */ MediaRouter2Manager mRouterManager;
+    boolean mIsScanning = false;
 
     private final Executor mExecutor = Executors.newSingleThreadExecutor();
 
@@ -58,14 +59,20 @@ public class ManagerInfoMediaManager extends InfoMediaManager {
 
     @Override
     protected void startScanOnRouter() {
-        mRouterManager.registerCallback(mExecutor, mMediaRouterCallback);
+        if (!mIsScanning) {
-        mRouterManager.registerScanRequest();
+            mRouterManager.registerCallback(mExecutor, mMediaRouterCallback);
+            mRouterManager.registerScanRequest();
+            mIsScanning = true;
+        }
     }
 
     @Override
     public void stopScan() {
-        mRouterManager.unregisterCallback(mMediaRouterCallback);
+        if (mIsScanning) {
-        mRouterManager.unregisterScanRequest();
+            mRouterManager.unregisterCallback(mMediaRouterCallback);
+            mRouterManager.unregisterScanRequest();
+            mIsScanning = false;
+        }
     }
 
     @Override

packages/SettingsLib/tests/robotests/src/com/android/settingslib/media/InfoMediaManagerTest.java

@@ -114,6 +114,23 @@ public class InfoMediaManagerTest {
         mInfoMediaManager.mRouterManager = MediaRouter2Manager.getInstance(mContext);
     }
 
+    @Test
+    public void stopScan_notStartFirst_notCallsUnregister() {
+        mInfoMediaManager.mRouterManager = mRouterManager;
+        mInfoMediaManager.stopScan();
+
+        verify(mRouterManager, never()).unregisterScanRequest();
+    }
+
+    @Test
+    public void stopScan_startFirst_callsUnregister() {
+        mInfoMediaManager.mRouterManager = mRouterManager;
+        mInfoMediaManager.startScan();
+        mInfoMediaManager.stopScan();
+
+        verify(mRouterManager).unregisterScanRequest();
+    }
+
     @Test
     public void onRouteAdded_getAvailableRoutes_shouldAddMediaDevice() {
         final List<RoutingSessionInfo> routingSessionInfos = new ArrayList<>();
@@ -328,11 +345,12 @@ public class InfoMediaManagerTest {
                 routeListingPreference);
         mInfoMediaManager.mMediaRouterCallback.onRoutesUpdated();
 
-        assertThat(mInfoMediaManager.mMediaDevices).hasSize(3);
+        assertThat(mInfoMediaManager.mMediaDevices).hasSize(4);
         assertThat(mInfoMediaManager.mMediaDevices.get(0).getId()).isEqualTo(TEST_ID);
-        assertThat(mInfoMediaManager.mMediaDevices.get(1).getId()).isEqualTo(TEST_ID_4);
+        assertThat(mInfoMediaManager.mMediaDevices.get(1).getId()).isEqualTo(TEST_ID_1);
-        assertThat(mInfoMediaManager.mMediaDevices.get(1).isSuggestedDevice()).isTrue();
+        assertThat(mInfoMediaManager.mMediaDevices.get(2).getId()).isEqualTo(TEST_ID_4);
-        assertThat(mInfoMediaManager.mMediaDevices.get(2).getId()).isEqualTo(TEST_ID_3);
+        assertThat(mInfoMediaManager.mMediaDevices.get(2).isSuggestedDevice()).isTrue();
+        assertThat(mInfoMediaManager.mMediaDevices.get(3).getId()).isEqualTo(TEST_ID_3);
     }
 
     @Test
@@ -406,8 +424,13 @@ public class InfoMediaManagerTest {
         when(availableInfo3.getClientPackageName()).thenReturn(packageName);
         availableRoutes.add(availableInfo3);
 
-        when(mRouterManager.getAvailableRoutes(packageName)).thenReturn(
+        final MediaRoute2Info availableInfo4 = mock(MediaRoute2Info.class);
-                availableRoutes);
+        when(availableInfo4.getId()).thenReturn(TEST_ID_1);
+        when(availableInfo4.isSystemRoute()).thenReturn(true);
+        when(availableInfo4.getClientPackageName()).thenReturn(packageName);
+        availableRoutes.add(availableInfo4);
+
+        when(mRouterManager.getAvailableRoutes(packageName)).thenReturn(availableRoutes);
 
         return availableRoutes;
     }