Demo apps: Annotate @NonNull where necessary

Because we now annotate not-null by default in ExoPlayer
library modules, we're seeing warnings in the demo apps where
we override a method and don't explicitly specify an equivalent
@NotNull annotation.

It's probably confusing to use not-null by default for the
demo apps, so this change uses @NonNull where necessary to fix
the warnings.

PiperOrigin-RevId: 296000044

demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/MainActivity.java

@@ -171,8 +171,6 @@ public class MainActivity extends AppCompatActivity
       showToast(R.string.error_unsupported_audio);
     } else if (trackType == C.TRACK_TYPE_VIDEO) {
       showToast(R.string.error_unsupported_video);
-    } else {
-      // Do nothing.
     }
   }
 
@@ -199,6 +197,7 @@ public class MainActivity extends AppCompatActivity
   private class MediaQueueListAdapter extends RecyclerView.Adapter<QueueItemViewHolder> {
 
     @Override
+    @NonNull
     public QueueItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
       TextView v = (TextView) LayoutInflater.from(parent.getContext())
           .inflate(android.R.layout.simple_list_item_1, parent, false);
@@ -236,7 +235,9 @@ public class MainActivity extends AppCompatActivity
     }
 
     @Override
-    public boolean onMove(RecyclerView list, RecyclerView.ViewHolder origin,
+    public boolean onMove(
+        @NonNull RecyclerView list,
+        RecyclerView.ViewHolder origin,
         RecyclerView.ViewHolder target) {
       int fromPosition = origin.getAdapterPosition();
       int toPosition = target.getAdapterPosition();
@@ -261,7 +262,7 @@ public class MainActivity extends AppCompatActivity
     }
 
     @Override
-    public void clearView(RecyclerView recyclerView, ViewHolder viewHolder) {
+    public void clearView(@NonNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder) {
       super.clearView(recyclerView, viewHolder);
       if (draggingFromPosition != C.INDEX_UNSET) {
         QueueItemViewHolder queueItemHolder = (QueueItemViewHolder) viewHolder;
@@ -300,8 +301,8 @@ public class MainActivity extends AppCompatActivity
       super(context, android.R.layout.simple_list_item_1, DemoUtil.SAMPLES);
     }
 
-    @NonNull
     @Override
+    @NonNull
     public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
       View view = super.getView(position, convertView, parent);
       ((TextView) view).setText(getItem(position).title);

demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java

@@ -19,6 +19,7 @@ import android.content.Context;
 import android.net.Uri;
 import android.view.KeyEvent;
 import android.view.View;
+import androidx.annotation.NonNull;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Player.DiscontinuityReason;
@@ -277,12 +278,13 @@ import java.util.Map;
   }
 
   @Override
-  public void onTimelineChanged(Timeline timeline, @TimelineChangeReason int reason) {
+  public void onTimelineChanged(@NonNull Timeline timeline, @TimelineChangeReason int reason) {
     updateCurrentItemIndex();
   }
 
   @Override
-  public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
+  public void onTracksChanged(
+      @NonNull TrackGroupArray trackGroups, @NonNull TrackSelectionArray trackSelections) {
     if (currentPlayer == exoPlayer && trackGroups != lastSeenTrackGroupArray) {
       MappingTrackSelector.MappedTrackInfo mappedTrackInfo =
           trackSelector.getCurrentMappedTrackInfo();

demos/gl/src/main/java/com/google/android/exoplayer2/gldemo/VideoProcessingGLSurfaceView.java

@@ -23,6 +23,7 @@ import android.opengl.GLES20;
 import android.opengl.GLSurfaceView;
 import android.os.Handler;
 import android.view.Surface;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.Player;
@@ -283,7 +284,7 @@ public final class VideoProcessingGLSurfaceView extends GLSurfaceView {
     public void onVideoFrameAboutToBeRendered(
         long presentationTimeUs,
         long releaseTimeNs,
-        Format format,
+        @NonNull Format format,
         @Nullable MediaFormat mediaFormat) {
       sampleTimestampQueue.add(releaseTimeNs, presentationTimeUs);
     }

demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoDownloadService.java

@@ -19,6 +19,7 @@ import static com.google.android.exoplayer2.demo.DemoApplication.DOWNLOAD_NOTIFI
 
 import android.app.Notification;
 import android.content.Context;
+import androidx.annotation.NonNull;
 import com.google.android.exoplayer2.offline.Download;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadService;
@@ -44,6 +45,7 @@ public class DemoDownloadService extends DownloadService {
   }
 
   @Override
+  @NonNull
   protected DownloadManager getDownloadManager() {
     // This will only happen once, because getDownloadManager is guaranteed to be called only once
     // in the life cycle of the process.
@@ -63,7 +65,8 @@ public class DemoDownloadService extends DownloadService {
   }
 
   @Override
-  protected Notification getForegroundNotification(List<Download> downloads) {
+  @NonNull
+  protected Notification getForegroundNotification(@NonNull List<Download> downloads) {
     return ((DemoApplication) getApplication())
         .getDownloadNotificationHelper()
         .buildProgressNotification(
@@ -91,7 +94,7 @@ public class DemoDownloadService extends DownloadService {
     }
 
     @Override
-    public void onDownloadChanged(DownloadManager manager, Download download) {
+    public void onDownloadChanged(@NonNull DownloadManager manager, @NonNull Download download) {
       Notification notification;
       if (download.state == Download.STATE_COMPLETED) {
         notification =

demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadTracker.java

@@ -19,6 +19,7 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.net.Uri;
 import android.widget.Toast;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.FragmentManager;
 import com.google.android.exoplayer2.C;
@@ -141,7 +142,8 @@ public class DownloadTracker {
   private class DownloadManagerListener implements DownloadManager.Listener {
 
     @Override
-    public void onDownloadChanged(DownloadManager downloadManager, Download download) {
+    public void onDownloadChanged(
+        @NonNull DownloadManager downloadManager, @NonNull Download download) {
       downloads.put(download.request.uri, download);
       for (Listener listener : listeners) {
         listener.onDownloadsChanged();
@@ -149,7 +151,8 @@ public class DownloadTracker {
     }
 
     @Override
-    public void onDownloadRemoved(DownloadManager downloadManager, Download download) {
+    public void onDownloadRemoved(
+        @NonNull DownloadManager downloadManager, @NonNull Download download) {
       downloads.remove(download.request.uri);
       for (Listener listener : listeners) {
         listener.onDownloadsChanged();
@@ -187,7 +190,7 @@ public class DownloadTracker {
     // DownloadHelper.Callback implementation.
 
     @Override
-    public void onPrepared(DownloadHelper helper) {
+    public void onPrepared(@NonNull DownloadHelper helper) {
       if (helper.getPeriodCount() == 0) {
         Log.d(TAG, "No periods found. Downloading entire stream.");
         startDownload();
@@ -214,7 +217,7 @@ public class DownloadTracker {
     }
 
     @Override
-    public void onPrepareError(DownloadHelper helper, IOException e) {
+    public void onPrepareError(@NonNull DownloadHelper helper, @NonNull IOException e) {
       Toast.makeText(context, R.string.download_start_error, Toast.LENGTH_LONG).show();
       Log.e(
           TAG,

demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java

@@ -298,7 +298,7 @@ public class PlayerActivity extends AppCompatActivity
   }
 
   @Override
-  public void onSaveInstanceState(Bundle outState) {
+  public void onSaveInstanceState(@NonNull Bundle outState) {
     super.onSaveInstanceState(outState);
     updateTrackSelectorParameters();
     updateStartPosition();
@@ -628,13 +628,15 @@ public class PlayerActivity extends AppCompatActivity
                 DrmSessionManager.getDummyDrmSessionManager();
 
             @Override
+            @NonNull
             public MediaSourceFactory setDrmSessionManager(DrmSessionManager<?> drmSessionManager) {
               this.drmSessionManager = drmSessionManager;
               return this;
             }
 
             @Override
-            public MediaSource createMediaSource(Uri uri) {
+            @NonNull
+            public MediaSource createMediaSource(@NonNull Uri uri) {
               return PlayerActivity.this.createLeafMediaSource(
                   uri, /* extension=*/ null, drmSessionManager);
             }
@@ -697,7 +699,7 @@ public class PlayerActivity extends AppCompatActivity
     }
 
     @Override
-    public void onPlayerError(ExoPlaybackException e) {
+    public void onPlayerError(@NonNull ExoPlaybackException e) {
       if (isBehindLiveWindow(e)) {
         clearStartPosition();
         initializePlayer();
@@ -709,7 +711,8 @@ public class PlayerActivity extends AppCompatActivity
 
     @Override
     @SuppressWarnings("ReferenceEquality")
-    public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
+    public void onTracksChanged(
+        @NonNull TrackGroupArray trackGroups, @NonNull TrackSelectionArray trackSelections) {
       updateButtonVisibility();
       if (trackGroups != lastSeenTrackGroupArray) {
         MappedTrackInfo mappedTrackInfo = trackSelector.getCurrentMappedTrackInfo();
@@ -731,7 +734,8 @@ public class PlayerActivity extends AppCompatActivity
   private class PlayerErrorMessageProvider implements ErrorMessageProvider<ExoPlaybackException> {
 
     @Override
-    public Pair<Integer, String> getErrorMessage(ExoPlaybackException e) {
+    @NonNull
+    public Pair<Integer, String> getErrorMessage(@NonNull ExoPlaybackException e) {
       String errorString = getString(R.string.error_generic);
       if (e.type == ExoPlaybackException.TYPE_RENDERER) {
         Exception cause = e.getRendererException();

demos/main/src/main/java/com/google/android/exoplayer2/demo/Sample.java

@@ -267,7 +267,7 @@ import java.util.UUID;
     }
   }
 
-  @Nullable public final String name;
+  public final String name;
 
   public Sample(String name) {
     this.name = name;

demos/main/src/main/java/com/google/android/exoplayer2/demo/TrackSelectionDialog.java

@@ -24,6 +24,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatDialog;
 import androidx.fragment.app.DialogFragment;
@@ -212,6 +213,7 @@ public final class TrackSelectionDialog extends DialogFragment {
   }
 
   @Override
+  @NonNull
   public Dialog onCreateDialog(Bundle savedInstanceState) {
     // We need to own the view to let tab layout work correctly on all API levels. We can't use
     // AlertDialog because it owns the view itself, so we use AppCompatDialog instead, themed using
@@ -223,16 +225,14 @@ public final class TrackSelectionDialog extends DialogFragment {
   }
 
   @Override
-  public void onDismiss(DialogInterface dialog) {
+  public void onDismiss(@NonNull DialogInterface dialog) {
     super.onDismiss(dialog);
     onDismissListener.onDismiss(dialog);
   }
 
-  @Nullable
   @Override
   public View onCreateView(
       LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
-
     View dialogView = inflater.inflate(R.layout.track_selection_dialog, container, false);
     TabLayout tabLayout = dialogView.findViewById(R.id.track_selection_dialog_tab_layout);
     ViewPager viewPager = dialogView.findViewById(R.id.track_selection_dialog_view_pager);
@@ -290,6 +290,7 @@ public final class TrackSelectionDialog extends DialogFragment {
     }
 
     @Override
+    @NonNull
     public Fragment getItem(int position) {
       return tabFragments.valueAt(position);
     }
@@ -299,7 +300,6 @@ public final class TrackSelectionDialog extends DialogFragment {
       return tabFragments.size();
     }
 
-    @Nullable
     @Override
     public CharSequence getPageTitle(int position) {
       return getTrackTypeString(getResources(), tabTrackTypes.get(position));
@@ -341,7 +341,6 @@ public final class TrackSelectionDialog extends DialogFragment {
       this.allowMultipleOverrides = allowMultipleOverrides;
     }
 
-    @Nullable
     @Override
     public View onCreateView(
         LayoutInflater inflater,
@@ -360,7 +359,8 @@ public final class TrackSelectionDialog extends DialogFragment {
     }
 
     @Override
-    public void onTrackSelectionChanged(boolean isDisabled, List<SelectionOverride> overrides) {
+    public void onTrackSelectionChanged(
+        boolean isDisabled, @NonNull List<SelectionOverride> overrides) {
       this.isDisabled = isDisabled;
       this.overrides = overrides;
     }

demos/surface/src/main/java/com/google/android/exoplayer2/surfacedemo/MainActivity.java

@@ -220,7 +220,8 @@ public final class MainActivity extends Activity {
       throw new IllegalStateException();
     }
     SimpleExoPlayer player = new SimpleExoPlayer.Builder(getApplicationContext()).build();
-    player.prepare(mediaSource);
+    player.setMediaSource(mediaSource);
+    player.prepare();
     player.play();
     player.setRepeatMode(Player.REPEAT_MODE_ALL);