Improve offline support in the demo app

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=195593235

demos/main/src/main/AndroidManifest.xml

@@ -75,8 +75,6 @@
       </intent-filter>
     </activity>
 
-    <activity android:name="com.google.android.exoplayer2.demo.DownloadActivity"/>
-
     <service android:name="com.google.android.exoplayer2.demo.DemoDownloadService"
         android:exported="false">
       <intent-filter>

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

@@ -43,6 +43,7 @@ import java.io.File;
 public class DemoApplication extends Application {
 
   private static final String DOWNLOAD_ACTION_FILE = "actions";
+  private static final String DOWNLOAD_TRACKER_ACTION_FILE = "tracked_actions";
   private static final String DOWNLOAD_CONTENT_DIRECTORY = "downloads";
   private static final int MAX_SIMULTANEOUS_DOWNLOADS = 2;
   private static final Deserializer[] DOWNLOAD_DESERIALIZERS =
@@ -58,6 +59,7 @@ public class DemoApplication extends Application {
   private File downloadDirectory;
   private Cache downloadCache;
   private DownloadManager downloadManager;
+  private DownloadTracker downloadTracker;
 
   @Override
   public void onCreate() {
@@ -83,20 +85,36 @@ public class DemoApplication extends Application {
     return "withExtensions".equals(BuildConfig.FLAVOR);
   }
 
-  /** Returns the download manager used by the application. */
-  public synchronized DownloadManager getDownloadManager() {
+  public DownloadManager getDownloadManager() {
+    initDownloadManager();
+    return downloadManager;
+  }
+
+  public DownloadTracker getDownloadTracker() {
+    initDownloadManager();
+    return downloadTracker;
+  }
+
+  private synchronized void initDownloadManager() {
     if (downloadManager == null) {
-      DownloaderConstructorHelper constructorHelper =
-          new DownloaderConstructorHelper(getDownloadCache(), buildHttpDataSourceFactory(null));
+      DownloaderConstructorHelper downloaderConstructorHelper =
+          new DownloaderConstructorHelper(
+              getDownloadCache(), buildHttpDataSourceFactory(/* listener= */ null));
       downloadManager =
           new DownloadManager(
-              constructorHelper,
+              downloaderConstructorHelper,
               MAX_SIMULTANEOUS_DOWNLOADS,
               DownloadManager.DEFAULT_MIN_RETRY_COUNT,
               new File(getDownloadDirectory(), DOWNLOAD_ACTION_FILE),
               DOWNLOAD_DESERIALIZERS);
+      downloadTracker =
+          new DownloadTracker(
+              /* context= */ this,
+              buildDataSourceFactory(/* listener= */ null),
+              new File(getDownloadDirectory(), DOWNLOAD_TRACKER_ACTION_FILE),
+              DOWNLOAD_DESERIALIZERS);
+      downloadManager.addListener(downloadTracker);
     }
-    return downloadManager;
   }
 
   private synchronized Cache getDownloadCache() {

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

@@ -1,196 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.google.android.exoplayer2.demo;
-
-import static com.google.android.exoplayer2.demo.PlayerActivity.EXTENSION_EXTRA;
-
-import android.app.Activity;
-import android.content.Intent;
-import android.net.Uri;
-import android.os.Bundle;
-import android.os.Parcelable;
-import android.view.View;
-import android.widget.ArrayAdapter;
-import android.widget.ListView;
-import android.widget.Toast;
-import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.offline.DownloadAction;
-import com.google.android.exoplayer2.offline.DownloadHelper;
-import com.google.android.exoplayer2.offline.DownloadService;
-import com.google.android.exoplayer2.offline.ProgressiveDownloadHelper;
-import com.google.android.exoplayer2.offline.SegmentDownloadAction;
-import com.google.android.exoplayer2.offline.TrackKey;
-import com.google.android.exoplayer2.source.TrackGroup;
-import com.google.android.exoplayer2.source.TrackGroupArray;
-import com.google.android.exoplayer2.source.dash.offline.DashDownloadHelper;
-import com.google.android.exoplayer2.source.hls.offline.HlsDownloadHelper;
-import com.google.android.exoplayer2.source.smoothstreaming.offline.SsDownloadHelper;
-import com.google.android.exoplayer2.ui.DefaultTrackNameProvider;
-import com.google.android.exoplayer2.ui.TrackNameProvider;
-import com.google.android.exoplayer2.upstream.DataSource;
-import com.google.android.exoplayer2.util.ParcelableArray;
-import com.google.android.exoplayer2.util.Util;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-
-/** An activity for downloading media. */
-public class DownloadActivity extends Activity {
-
-  public static final String PLAYER_INTENT = "player_intent";
-  public static final String SAMPLE_NAME = "sample_name";
-
-  private Intent playerIntent;
-  private String sampleName;
-
-  private TrackNameProvider trackNameProvider;
-  private DownloadHelper downloadHelper;
-  private ListView trackList;
-  private ArrayAdapter<String> arrayAdapter;
-  private ArrayList<TrackKey> trackKeys;
-
-  @Override
-  protected void onCreate(Bundle savedInstanceState) {
-    super.onCreate(savedInstanceState);
-    setContentView(R.layout.downloader_activity);
-    trackNameProvider = new DefaultTrackNameProvider(getResources());
-
-    Intent intent = getIntent();
-    playerIntent = intent.getParcelableExtra(PLAYER_INTENT);
-    Uri sampleUri = playerIntent.getData();
-    sampleName = intent.getStringExtra(SAMPLE_NAME);
-    getActionBar().setTitle(sampleName);
-
-    arrayAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_multiple_choice);
-    trackList = findViewById(R.id.representation_list);
-    trackList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
-    trackList.setAdapter(arrayAdapter);
-    trackKeys = new ArrayList<>();
-
-    DemoApplication application = (DemoApplication) getApplication();
-    DataSource.Factory manifestDataSourceFactory =
-        application.buildDataSourceFactory(/* listener= */ null);
-    String extension = playerIntent.getStringExtra(EXTENSION_EXTRA);
-    int type = Util.inferContentType(sampleUri, extension);
-    switch (type) {
-      case C.TYPE_DASH:
-        downloadHelper = new DashDownloadHelper(sampleUri, manifestDataSourceFactory);
-        break;
-      case C.TYPE_SS:
-        downloadHelper = new SsDownloadHelper(sampleUri, manifestDataSourceFactory);
-        break;
-      case C.TYPE_HLS:
-        downloadHelper = new HlsDownloadHelper(sampleUri, manifestDataSourceFactory);
-        break;
-      case C.TYPE_OTHER:
-        downloadHelper = new ProgressiveDownloadHelper(sampleUri);
-        break;
-      default:
-        throw new IllegalStateException("Unsupported type: " + type);
-    }
-
-    downloadHelper.prepare(
-        new DownloadHelper.Callback() {
-          @Override
-          public void onPrepared(DownloadHelper helper) {
-            DownloadActivity.this.onPrepared();
-          }
-
-          @Override
-          public void onPrepareError(DownloadHelper helper, IOException e) {
-            DownloadActivity.this.onPrepareError();
-          }
-        });
-  }
-
-  private void onPrepared() {
-    for (int i = 0; i < downloadHelper.getPeriodCount(); i++) {
-      TrackGroupArray trackGroups = downloadHelper.getTrackGroups(i);
-      for (int j = 0; j < trackGroups.length; j++) {
-        TrackGroup trackGroup = trackGroups.get(j);
-        for (int k = 0; k < trackGroup.length; k++) {
-          arrayAdapter.add(trackNameProvider.getTrackName(trackGroup.getFormat(k)));
-          trackKeys.add(new TrackKey(i, j, k));
-        }
-      }
-    }
-  }
-
-  private void onPrepareError() {
-    Toast.makeText(
-            getApplicationContext(), R.string.download_manifest_load_error, Toast.LENGTH_LONG)
-        .show();
-  }
-
-  // This method is referenced in the layout file
-  public void onClick(View v) {
-    // switch-case doesn't work as in some compile configurations id definitions aren't constant
-    int id = v.getId();
-    if (id == R.id.download_button) {
-      startDownload();
-    } else if (id == R.id.remove_all_button) {
-      removeDownload();
-    } else if (id == R.id.play_button) {
-      playDownload();
-    }
-  }
-
-  private void startDownload() {
-    List<TrackKey> selectedTrackKeys = getSelectedTrackKeys();
-    if (trackKeys.isEmpty() || !selectedTrackKeys.isEmpty()) {
-      DownloadService.addDownloadAction(
-          this,
-          DemoDownloadService.class,
-          downloadHelper.getDownloadAction(Util.getUtf8Bytes(sampleName), selectedTrackKeys));
-    }
-  }
-
-  private void removeDownload() {
-    DownloadService.addDownloadAction(
-        this,
-        DemoDownloadService.class,
-        downloadHelper.getRemoveAction(Util.getUtf8Bytes(sampleName)));
-    for (int i = 0; i < trackList.getChildCount(); i++) {
-      trackList.setItemChecked(i, false);
-    }
-  }
-
-  private void playDownload() {
-    DownloadAction action = downloadHelper.getDownloadAction(null, getSelectedTrackKeys());
-    List<? extends ParcelableArray> keys = null;
-    if (action instanceof SegmentDownloadAction) {
-      keys = ((SegmentDownloadAction) action).keys;
-    }
-    if (keys.isEmpty()) {
-      playerIntent.removeExtra(PlayerActivity.MANIFEST_FILTER_EXTRA);
-    } else {
-      playerIntent.putExtra(
-          PlayerActivity.MANIFEST_FILTER_EXTRA,
-          new ParcelableArray(keys.toArray(new Parcelable[0])));
-    }
-    startActivity(playerIntent);
-  }
-
-  private List<TrackKey> getSelectedTrackKeys() {
-    ArrayList<TrackKey> selectedTrackKeys = new ArrayList<>();
-    for (int i = 0; i < trackList.getChildCount(); i++) {
-      if (trackList.isItemChecked(i)) {
-        selectedTrackKeys.add(trackKeys.get(i));
-      }
-    }
-    return selectedTrackKeys;
-  }
-}

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

@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.demo;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.ArrayAdapter;
+import android.widget.ListView;
+import android.widget.Toast;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.offline.ActionFile;
+import com.google.android.exoplayer2.offline.DownloadAction;
+import com.google.android.exoplayer2.offline.DownloadHelper;
+import com.google.android.exoplayer2.offline.DownloadManager;
+import com.google.android.exoplayer2.offline.DownloadManager.TaskState;
+import com.google.android.exoplayer2.offline.DownloadService;
+import com.google.android.exoplayer2.offline.ProgressiveDownloadHelper;
+import com.google.android.exoplayer2.offline.SegmentDownloadAction;
+import com.google.android.exoplayer2.offline.TrackKey;
+import com.google.android.exoplayer2.source.TrackGroup;
+import com.google.android.exoplayer2.source.TrackGroupArray;
+import com.google.android.exoplayer2.source.dash.offline.DashDownloadHelper;
+import com.google.android.exoplayer2.source.hls.offline.HlsDownloadHelper;
+import com.google.android.exoplayer2.source.smoothstreaming.offline.SsDownloadHelper;
+import com.google.android.exoplayer2.ui.DefaultTrackNameProvider;
+import com.google.android.exoplayer2.ui.TrackNameProvider;
+import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.util.Util;
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArraySet;
+
+/**
+ * Tracks media that has been downloaded.
+ *
+ * <p>Tracked downloads are persisted using an {@link ActionFile}, however in a real application
+ * it's expected that state will be stored directly in the application's media database, so that it
+ * can be queried efficiently together with other information about the media.
+ */
+public class DownloadTracker implements DownloadManager.Listener {
+
+  /** Listens for changes in the tracked downloads. */
+  public interface Listener {
+
+    /** Called when the tracked downloads changed. */
+    void onDownloadsChanged();
+  }
+
+  private static final String TAG = "DownloadTracker";
+
+  private final Context context;
+  private final DataSource.Factory dataSourceFactory;
+  private final TrackNameProvider trackNameProvider;
+  private final CopyOnWriteArraySet<Listener> listeners;
+  private final HashMap<Uri, DownloadAction> trackedDownloadStates;
+  private final ActionFile actionFile;
+  private final Handler actionFileWriteHandler;
+
+  public DownloadTracker(
+      Context context,
+      DataSource.Factory dataSourceFactory,
+      File actionFile,
+      DownloadAction.Deserializer[] deserializers) {
+    this.context = context.getApplicationContext();
+    this.dataSourceFactory = dataSourceFactory;
+    this.actionFile = new ActionFile(actionFile);
+    trackNameProvider = new DefaultTrackNameProvider(context.getResources());
+    listeners = new CopyOnWriteArraySet<>();
+    trackedDownloadStates = new HashMap<>();
+    HandlerThread actionFileWriteThread = new HandlerThread("DownloadTracker");
+    actionFileWriteThread.start();
+    actionFileWriteHandler = new Handler(actionFileWriteThread.getLooper());
+    loadTrackedActions(deserializers);
+  }
+
+  public void addListener(Listener listener) {
+    listeners.add(listener);
+  }
+
+  public void removeListener(Listener listener) {
+    listeners.remove(listener);
+  }
+
+  public boolean isDownloaded(Uri uri) {
+    return trackedDownloadStates.containsKey(uri);
+  }
+
+  @SuppressWarnings("unchecked")
+  public <K> List<K> getOfflineStreamKeys(Uri uri) {
+    if (!trackedDownloadStates.containsKey(uri)) {
+      return Collections.emptyList();
+    }
+    DownloadAction action = trackedDownloadStates.get(uri);
+    if (action instanceof SegmentDownloadAction) {
+      return ((SegmentDownloadAction) action).keys;
+    }
+    return Collections.emptyList();
+  }
+
+  public void toggleDownload(Activity activity, String name, Uri uri, String extension) {
+    if (isDownloaded(uri)) {
+      DownloadAction removeAction =
+          getDownloadHelper(uri, extension).getRemoveAction(Util.getUtf8Bytes(name));
+      addDownloadAction(removeAction);
+    } else {
+      StartDownloadDialogHelper helper =
+          new StartDownloadDialogHelper(activity, getDownloadHelper(uri, extension), name);
+      helper.prepare();
+    }
+  }
+
+  // DownloadManager.Listener
+
+  @Override
+  public void onTaskStateChanged(DownloadManager downloadManager, TaskState taskState) {
+    DownloadAction action = taskState.action;
+    Uri uri = action.uri;
+    if ((action.isRemoveAction && taskState.state == TaskState.STATE_COMPLETED)
+        || (!action.isRemoveAction && taskState.state == TaskState.STATE_FAILED)) {
+      // A download has been removed, or has failed. Stop tracking it.
+      if (trackedDownloadStates.remove(uri) != null) {
+        handleTrackedDownloadStatesChanged();
+      }
+    }
+  }
+
+  @Override
+  public void onIdle(DownloadManager downloadManager) {
+    // Do nothing.
+  }
+
+  // Internal methods
+
+  private void loadTrackedActions(DownloadAction.Deserializer[] deserializers) {
+    try {
+      DownloadAction[] allActions = actionFile.load(deserializers);
+      for (DownloadAction action : allActions) {
+        trackedDownloadStates.put(action.uri, action);
+      }
+    } catch (IOException e) {
+      Log.e(TAG, "Failed to load tracked actions", e);
+    }
+  }
+
+  private void handleTrackedDownloadStatesChanged() {
+    for (Listener listener : listeners) {
+      listener.onDownloadsChanged();
+    }
+    final DownloadAction[] actions = trackedDownloadStates.values().toArray(new DownloadAction[0]);
+    actionFileWriteHandler.post(
+        new Runnable() {
+          @Override
+          public void run() {
+            try {
+              actionFile.store(actions);
+            } catch (IOException e) {
+              Log.e(TAG, "Failed to store tracked actions", e);
+            }
+          }
+        });
+  }
+
+  private void startDownload(DownloadAction action) {
+    if (trackedDownloadStates.containsKey(action.uri)) {
+      // This content is already being downloaded. Do nothing.
+      return;
+    }
+    trackedDownloadStates.put(action.uri, action);
+    handleTrackedDownloadStatesChanged();
+    addDownloadAction(action);
+  }
+
+  private void addDownloadAction(DownloadAction action) {
+    DownloadService.addDownloadAction(context, DemoDownloadService.class, action);
+  }
+
+  private DownloadHelper getDownloadHelper(Uri uri, String extension) {
+    int type = Util.inferContentType(uri, extension);
+    switch (type) {
+      case C.TYPE_DASH:
+        return new DashDownloadHelper(uri, dataSourceFactory);
+      case C.TYPE_SS:
+        return new SsDownloadHelper(uri, dataSourceFactory);
+      case C.TYPE_HLS:
+        return new HlsDownloadHelper(uri, dataSourceFactory);
+      case C.TYPE_OTHER:
+        return new ProgressiveDownloadHelper(uri);
+      default:
+        throw new IllegalStateException("Unsupported type: " + type);
+    }
+  }
+
+  private final class StartDownloadDialogHelper
+      implements DownloadHelper.Callback, DialogInterface.OnClickListener {
+
+    private final DownloadHelper downloadHelper;
+    private final String name;
+
+    private final AlertDialog.Builder builder;
+    private final View dialogView;
+    private final List<TrackKey> trackKeys;
+    private final ArrayAdapter<String> trackTitles;
+    private final ListView representationList;
+
+    public StartDownloadDialogHelper(
+        Activity activity, DownloadHelper downloadHelper, String name) {
+      this.downloadHelper = downloadHelper;
+      this.name = name;
+      builder =
+          new AlertDialog.Builder(activity)
+              .setTitle(R.string.exo_download_description)
+              .setPositiveButton(android.R.string.ok, this)
+              .setNegativeButton(android.R.string.cancel, null);
+
+      // Inflate with the builder's context to ensure the correct style is used.
+      LayoutInflater dialogInflater = LayoutInflater.from(builder.getContext());
+      dialogView = dialogInflater.inflate(R.layout.start_download_dialog, null);
+
+      trackKeys = new ArrayList<>();
+      trackTitles =
+          new ArrayAdapter<>(
+              builder.getContext(), android.R.layout.simple_list_item_multiple_choice);
+      representationList = dialogView.findViewById(R.id.representation_list);
+      representationList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
+      representationList.setAdapter(trackTitles);
+    }
+
+    public void prepare() {
+      downloadHelper.prepare(this);
+    }
+
+    @Override
+    public void onPrepared(DownloadHelper helper) {
+      for (int i = 0; i < downloadHelper.getPeriodCount(); i++) {
+        TrackGroupArray trackGroups = downloadHelper.getTrackGroups(i);
+        for (int j = 0; j < trackGroups.length; j++) {
+          TrackGroup trackGroup = trackGroups.get(j);
+          for (int k = 0; k < trackGroup.length; k++) {
+            trackKeys.add(new TrackKey(i, j, k));
+            trackTitles.add(trackNameProvider.getTrackName(trackGroup.getFormat(k)));
+          }
+        }
+        if (!trackKeys.isEmpty()) {
+          builder.setView(dialogView);
+        }
+        builder.create().show();
+      }
+    }
+
+    @Override
+    public void onPrepareError(DownloadHelper helper, IOException e) {
+      Toast.makeText(
+              context.getApplicationContext(), R.string.download_start_error, Toast.LENGTH_LONG)
+          .show();
+    }
+
+    @Override
+    public void onClick(DialogInterface dialog, int which) {
+      ArrayList<TrackKey> selectedTrackKeys = new ArrayList<>();
+      for (int i = 0; i < representationList.getChildCount(); i++) {
+        if (representationList.isItemChecked(i)) {
+          selectedTrackKeys.add(trackKeys.get(i));
+        }
+      }
+      if (!selectedTrackKeys.isEmpty() || trackKeys.isEmpty()) {
+        // We have selected keys, or we're dealing with single stream content.
+        DownloadAction downloadAction =
+            downloadHelper.getDownloadAction(Util.getUtf8Bytes(name), selectedTrackKeys);
+        startDownload(downloadAction);
+      }
+    }
+  }
+}

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

@@ -21,7 +21,6 @@ import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Bundle;
-import android.os.Parcelable;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.util.Pair;
@@ -83,7 +82,6 @@ import com.google.android.exoplayer2.upstream.DefaultBandwidthMeter;
 import com.google.android.exoplayer2.upstream.HttpDataSource;
 import com.google.android.exoplayer2.util.ErrorMessageProvider;
 import com.google.android.exoplayer2.util.EventLogger;
-import com.google.android.exoplayer2.util.ParcelableArray;
 import com.google.android.exoplayer2.util.Util;
 import java.lang.reflect.Constructor;
 import java.net.CookieHandler;
@@ -104,13 +102,11 @@ public class PlayerActivity extends Activity
 
   public static final String ACTION_VIEW = "com.google.android.exoplayer.demo.action.VIEW";
   public static final String EXTENSION_EXTRA = "extension";
-  public static final String MANIFEST_FILTER_EXTRA = "manifest_filter";
 
   public static final String ACTION_VIEW_LIST =
       "com.google.android.exoplayer.demo.action.VIEW_LIST";
   public static final String URI_LIST_EXTRA = "uri_list";
   public static final String EXTENSION_LIST_EXTRA = "extension_list";
-  public static final String MANIFEST_FILTER_LIST_EXTRA = "manifest_filter_list";
 
   public static final String AD_TAG_URI_EXTRA = "ad_tag_uri";
 
@@ -313,11 +309,9 @@ public class PlayerActivity extends Activity
       String action = intent.getAction();
       Uri[] uris;
       String[] extensions;
-      Parcelable[] manifestFilters;
       if (ACTION_VIEW.equals(action)) {
         uris = new Uri[] {intent.getData()};
         extensions = new String[] {intent.getStringExtra(EXTENSION_EXTRA)};
-        manifestFilters = new Parcelable[] {intent.getParcelableExtra(MANIFEST_FILTER_EXTRA)};
       } else if (ACTION_VIEW_LIST.equals(action)) {
         String[] uriStrings = intent.getStringArrayExtra(URI_LIST_EXTRA);
         uris = new Uri[uriStrings.length];
@@ -328,10 +322,6 @@ public class PlayerActivity extends Activity
         if (extensions == null) {
           extensions = new String[uriStrings.length];
         }
-        manifestFilters = intent.getParcelableArrayExtra(MANIFEST_FILTER_LIST_EXTRA);
-        if (manifestFilters == null) {
-          manifestFilters = new Parcelable[uriStrings.length];
-        }
       } else {
         showToast(getString(R.string.unexpected_intent_action, action));
         finish();
@@ -413,9 +403,7 @@ public class PlayerActivity extends Activity
 
       MediaSource[] mediaSources = new MediaSource[uris.length];
       for (int i = 0; i < uris.length; i++) {
-        ParcelableArray<?> manifestFilter = (ParcelableArray<?>) manifestFilters[i];
-        List<?> filter = manifestFilter != null ? manifestFilter.asList() : null;
-        mediaSources[i] = buildMediaSource(uris[i], extensions[i], filter);
+        mediaSources[i] = buildMediaSource(uris[i], extensions[i]);
       }
       mediaSource =
           mediaSources.length == 1 ? mediaSources[0] : new ConcatenatingMediaSource(mediaSources);
@@ -445,12 +433,11 @@ public class PlayerActivity extends Activity
   }
 
   private MediaSource buildMediaSource(Uri uri) {
-    return buildMediaSource(uri, null, null);
+    return buildMediaSource(uri, null);
   }
 
   @SuppressWarnings("unchecked")
-  private MediaSource buildMediaSource(
-      Uri uri, @Nullable String overrideExtension, @Nullable List<?> manifestFilter) {
+  private MediaSource buildMediaSource(Uri uri, @Nullable String overrideExtension) {
     @ContentType int type = Util.inferContentType(uri, overrideExtension);
     switch (type) {
       case C.TYPE_DASH:
@@ -459,7 +446,7 @@ public class PlayerActivity extends Activity
                 buildDataSourceFactory(false))
             .setManifestParser(
                 new FilteringManifestParser<>(
-                    new DashManifestParser(), (List<RepresentationKey>) manifestFilter))
+                    new DashManifestParser(), (List<RepresentationKey>) getOfflineStreamKeys(uri)))
             .createMediaSource(uri);
       case C.TYPE_SS:
         return new SsMediaSource.Factory(
@@ -467,13 +454,13 @@ public class PlayerActivity extends Activity
                 buildDataSourceFactory(false))
             .setManifestParser(
                 new FilteringManifestParser<>(
-                    new SsManifestParser(), (List<StreamKey>) manifestFilter))
+                    new SsManifestParser(), (List<StreamKey>) getOfflineStreamKeys(uri)))
             .createMediaSource(uri);
       case C.TYPE_HLS:
         return new HlsMediaSource.Factory(mediaDataSourceFactory)
             .setPlaylistParser(
                 new FilteringManifestParser<>(
-                    new HlsPlaylistParser(), (List<RenditionKey>) manifestFilter))
+                    new HlsPlaylistParser(), (List<RenditionKey>) getOfflineStreamKeys(uri)))
             .createMediaSource(uri);
       case C.TYPE_OTHER:
         return new ExtractorMediaSource.Factory(mediaDataSourceFactory).createMediaSource(uri);
@@ -483,6 +470,10 @@ public class PlayerActivity extends Activity
     }
   }
 
+  private List<?> getOfflineStreamKeys(Uri uri) {
+    return ((DemoApplication) getApplication()).getDownloadTracker().getOfflineStreamKeys(uri);
+  }
+
   private DefaultDrmSessionManager<FrameworkMediaCrypto> buildDrmSessionManagerV18(
       UUID uuid, String licenseUrl, String[] keyRequestPropertiesArray, boolean multiSession)
       throws UnsupportedDrmException {

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

@@ -24,7 +24,6 @@ import android.os.AsyncTask;
 import android.os.Bundle;
 import android.util.JsonReader;
 import android.util.Log;
-import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
@@ -47,17 +46,27 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 /** An activity for selecting from a list of media samples. */
-public class SampleChooserActivity extends Activity {
+public class SampleChooserActivity extends Activity
+    implements DownloadTracker.Listener, OnChildClickListener {
 
   private static final String TAG = "SampleChooserActivity";
 
+  private DownloadTracker downloadTracker;
+  private SampleAdapter sampleAdapter;
+
   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.sample_chooser_activity);
+    sampleAdapter = new SampleAdapter();
+    ExpandableListView sampleListView = findViewById(R.id.sample_list);
+    sampleListView.setAdapter(sampleAdapter);
+    sampleListView.setOnChildClickListener(this);
+
     Intent intent = getIntent();
     String dataUri = intent.getDataString();
     String[] uris;
@@ -80,10 +89,30 @@ public class SampleChooserActivity extends Activity {
       uriList.toArray(uris);
       Arrays.sort(uris);
     }
+
+    downloadTracker = ((DemoApplication) getApplication()).getDownloadTracker();
+    startDownloadServiceForeground();
+
     SampleListLoader loaderTask = new SampleListLoader();
     loaderTask.execute(uris);
+  }
 
-    startDownloadServiceForeground();
+  @Override
+  public void onStart() {
+    super.onStart();
+    downloadTracker.addListener(this);
+    sampleAdapter.notifyDataSetChanged();
+  }
+
+  @Override
+  public void onStop() {
+    downloadTracker.removeListener(this);
+    super.onStop();
+  }
+
+  @Override
+  public void onDownloadsChanged() {
+    sampleAdapter.notifyDataSetChanged();
   }
 
   private void startDownloadServiceForeground() {
@@ -96,28 +125,44 @@ public class SampleChooserActivity extends Activity {
       Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
           .show();
     }
-    ExpandableListView sampleList = findViewById(R.id.sample_list);
-    sampleList.setAdapter(new SampleAdapter(this, groups));
-    sampleList.setOnChildClickListener(
-        new OnChildClickListener() {
+    sampleAdapter.setSampleGroups(groups);
+  }
+
   @Override
   public boolean onChildClick(
       ExpandableListView parent, View view, int groupPosition, int childPosition, long id) {
-            onSampleClicked(groups.get(groupPosition).samples.get(childPosition));
-            return true;
-          }
-        });
-  }
-
-  private void onSampleClicked(Sample sample) {
+    Sample sample = (Sample) view.getTag();
     startActivity(sample.buildIntent(this));
+    return true;
   }
 
   private void onSampleDownloadButtonClicked(Sample sample) {
-    Intent intent = new Intent(this, DownloadActivity.class);
-    intent.putExtra(DownloadActivity.SAMPLE_NAME, sample.name);
-    intent.putExtra(DownloadActivity.PLAYER_INTENT, sample.buildIntent(this));
-    startActivity(intent);
+    int downloadUnsupportedStringId = getDownloadUnsupportedStringId(sample);
+    if (downloadUnsupportedStringId != 0) {
+      Toast.makeText(getApplicationContext(), downloadUnsupportedStringId, Toast.LENGTH_LONG)
+          .show();
+    } else {
+      UriSample uriSample = (UriSample) sample;
+      downloadTracker.toggleDownload(this, sample.name, uriSample.uri, uriSample.extension);
+    }
+  }
+
+  private int getDownloadUnsupportedStringId(Sample sample) {
+    if (sample instanceof PlaylistSample) {
+      return R.string.download_playlist_unsupported;
+    }
+    UriSample uriSample = (UriSample) sample;
+    if (uriSample.drmInfo != null) {
+      return R.string.download_drm_unsupported;
+    }
+    if (uriSample.adTagUri != null) {
+      return R.string.download_ads_unsupported;
+    }
+    String scheme = uriSample.uri.getScheme();
+    if (!("http".equals(scheme) || "https".equals(scheme))) {
+      return R.string.download_scheme_unsupported;
+    }
+    return 0;
   }
 
   private final class SampleListLoader extends AsyncTask<String, Void, List<SampleGroup>> {
@@ -296,12 +341,15 @@ public class SampleChooserActivity extends Activity {
 
   private final class SampleAdapter extends BaseExpandableListAdapter implements OnClickListener {
 
-    private final Context context;
-    private final List<SampleGroup> sampleGroups;
+    private List<SampleGroup> sampleGroups;
 
-    public SampleAdapter(Context context, List<SampleGroup> sampleGroups) {
-      this.context = context;
+    public SampleAdapter() {
+      sampleGroups = Collections.emptyList();
+    }
+
+    public void setSampleGroups(List<SampleGroup> sampleGroups) {
       this.sampleGroups = sampleGroups;
+      notifyDataSetChanged();
     }
 
     @Override
@@ -319,7 +367,7 @@ public class SampleChooserActivity extends Activity {
         View convertView, ViewGroup parent) {
       View view = convertView;
       if (view == null) {
-        view = LayoutInflater.from(context).inflate(R.layout.sample_list_item, parent, false);
+        view = getLayoutInflater().inflate(R.layout.sample_list_item, parent, false);
         View downloadButton = view.findViewById(R.id.download_button);
         downloadButton.setOnClickListener(this);
         downloadButton.setFocusable(false);
@@ -348,8 +396,9 @@ public class SampleChooserActivity extends Activity {
         ViewGroup parent) {
       View view = convertView;
       if (view == null) {
-        view = LayoutInflater.from(context).inflate(android.R.layout.simple_expandable_list_item_1,
-            parent, false);
+        view =
+            getLayoutInflater()
+                .inflate(android.R.layout.simple_expandable_list_item_1, parent, false);
       }
       ((TextView) view).setText(getGroup(groupPosition).title);
       return view;
@@ -376,24 +425,18 @@ public class SampleChooserActivity extends Activity {
     }
 
     private void initializeChildView(View view, Sample sample) {
+      view.setTag(sample);
       TextView sampleTitle = view.findViewById(R.id.sample_title);
       sampleTitle.setText(sample.name);
+
+      boolean canDownload = getDownloadUnsupportedStringId(sample) == 0;
+      boolean isDownloaded = canDownload && downloadTracker.isDownloaded(((UriSample) sample).uri);
       ImageButton downloadButton = view.findViewById(R.id.download_button);
       downloadButton.setTag(sample);
-      downloadButton.setColorFilter(0xFFBBBBBB);
-      downloadButton.setVisibility(canDownload(sample) ? View.VISIBLE : View.GONE);
-    }
-
-    private boolean canDownload(Sample sample) {
-      if (!(sample instanceof UriSample)) {
-        return false;
-      }
-      UriSample uriSample = (UriSample) sample;
-      if (uriSample.drmInfo != null || uriSample.adTagUri != null) {
-        return false;
-      }
-      String scheme = uriSample.uri.getScheme();
-      return "http".equals(scheme) || "https".equals(scheme);
+      downloadButton.setColorFilter(
+          canDownload ? (isDownloaded ? 0xFF42A5F5 : 0xFFBDBDBD) : 0xFFEEEEEE);
+      downloadButton.setImageResource(
+          isDownloaded ? R.drawable.ic_download_done : R.drawable.ic_download);
     }
   }
 

demos/main/src/main/res/layout/downloader_activity.xml

@@ -1,51 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2017 The Android Open Source Project
-
-     Licensed under the Apache License, Version 2.0 (the "License");
-     you may not use this file except in compliance with the License.
-     You may obtain a copy of the License at
-
-          http://www.apache.org/licenses/LICENSE-2.0
-
-     Unless required by applicable law or agreed to in writing, software
-     distributed under the License is distributed on an "AS IS" BASIS,
-     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     See the License for the specific language governing permissions and
-     limitations under the License.
--->
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/activity_downloader"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:orientation="vertical">
-
-  <LinearLayout
-      android:layout_width="match_parent"
-      android:layout_height="wrap_content"
-      android:orientation="horizontal">
-
-    <Button android:id="@+id/download_button"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:onClick="onClick"
-        android:text="@string/exo_download_description"/>
-
-    <Button android:id="@+id/remove_all_button"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:onClick="onClick"
-        android:text="@string/download_remove_all"/>
-
-    <Button android:id="@+id/play_button"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:onClick="onClick"
-        android:text="@string/exo_controls_play_description"/>
-
-  </LinearLayout>
-
-  <ListView android:id="@+id/representation_list"
-      android:layout_width="match_parent"
-      android:layout_height="match_parent"/>
-
-</LinearLayout>

demos/main/src/main/res/layout/sample_list_item.xml

@@ -33,7 +33,6 @@
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:contentDescription="@string/exo_download_description"
-      android:background="@android:color/transparent"
-      android:src="@drawable/ic_offline_pin_white_36dp"/>
+      android:background="@android:color/transparent"/>
 
 </LinearLayout>

demos/main/src/main/res/layout/start_download_dialog.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2018 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<ListView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/representation_list"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"/>

demos/main/src/main/res/values/strings.xml

@@ -47,8 +47,14 @@
 
   <string name="ima_not_loaded">Playing sample without ads, as the IMA extension was not loaded</string>
 
-  <string name="download_manifest_load_error">Failed to download manifest</string>
+  <string name="download_start_error">Failed to start download</string>
 
-  <string name="download_remove_all">Remove all</string>
+  <string name="download_playlist_unsupported">This demo app does not support downloading playlists</string>
+
+  <string name="download_drm_unsupported">This demo app does not support downloading protected content</string>
+
+  <string name="download_scheme_unsupported">This demo app only supports downloading http streams</string>
+
+  <string name="download_ads_unsupported">IMA does not support offline ads</string>
 
 </resources>

library/core/src/main/java/com/google/android/exoplayer2/util/ParcelableArray.java

@@ -1,64 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.google.android.exoplayer2.util;
-
-import android.os.Parcel;
-import android.os.Parcelable;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-
-/** A {@link android.os.Parcelable} wrapper around an array. */
-public final class ParcelableArray<V extends Parcelable> implements Parcelable {
-
-  @SuppressWarnings("rawtypes") // V cannot be obtained from static context
-  public static final Creator<ParcelableArray> CREATOR =
-      new Creator<ParcelableArray>() {
-        @SuppressWarnings("unchecked")
-        @Override
-        public ParcelableArray createFromParcel(Parcel in) {
-          ClassLoader classLoader = ParcelableArray.class.getClassLoader();
-          Parcelable[] elements = in.readParcelableArray(classLoader);
-          return new ParcelableArray(elements);
-        }
-
-        @Override
-        public ParcelableArray[] newArray(int size) {
-          return new ParcelableArray[size];
-        }
-      };
-
-  private final V[] elements;
-
-  public ParcelableArray(V[] elements) {
-    this.elements = elements;
-  }
-
-  /** Returns an unmodifiable list containing all elements. */
-  public List<V> asList() {
-    return Collections.unmodifiableList(Arrays.asList(elements));
-  }
-
-  @Override
-  public int describeContents() {
-    return 0;
-  }
-
-  @Override
-  public void writeToParcel(Parcel dest, int flags) {
-    dest.writeParcelableArray(elements, flags);
-  }
-}

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/RepresentationKey.java

@@ -15,15 +15,11 @@
  */
 package com.google.android.exoplayer2.source.dash.manifest;
 
-import android.os.Parcel;
-import android.os.Parcelable;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
-/**
- * Uniquely identifies a {@link Representation} in a {@link DashManifest}.
- */
-public final class RepresentationKey implements Parcelable, Comparable<RepresentationKey> {
+/** Uniquely identifies a {@link Representation} in a {@link DashManifest}. */
+public final class RepresentationKey implements Comparable<RepresentationKey> {
 
   public final int periodIndex;
   public final int adaptationSetIndex;
@@ -77,31 +73,4 @@ public final class RepresentationKey implements Parcelable, Comparable<Represent
     return result;
   }
 
-  // Parcelable implementation.
-
-  @Override
-  public int describeContents() {
-    return 0;
-  }
-
-  @Override
-  public void writeToParcel(Parcel dest, int flags) {
-    dest.writeInt(periodIndex);
-    dest.writeInt(adaptationSetIndex);
-    dest.writeInt(representationIndex);
-  }
-
-  public static final Creator<RepresentationKey> CREATOR =
-      new Creator<RepresentationKey>() {
-        @Override
-        public RepresentationKey createFromParcel(Parcel in) {
-          return new RepresentationKey(in.readInt(), in.readInt(), in.readInt());
-        }
-
-        @Override
-        public RepresentationKey[] newArray(int size) {
-          return new RepresentationKey[size];
-        }
-      };
-
 }

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/RenditionKey.java

@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.source.hls.playlist;
 
-import android.os.Parcel;
-import android.os.Parcelable;
 import android.support.annotation.IntDef;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -24,7 +22,7 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
 /** Uniquely identifies a rendition in an {@link HlsMasterPlaylist}. */
-public final class RenditionKey implements Parcelable, Comparable<RenditionKey> {
+public final class RenditionKey implements Comparable<RenditionKey> {
 
   /** Types of rendition. */
   @Retention(RetentionPolicy.SOURCE)
@@ -78,30 +76,4 @@ public final class RenditionKey implements Parcelable, Comparable<RenditionKey>
     }
     return result;
   }
-
-  // Parcelable implementation.
-
-  @Override
-  public int describeContents() {
-    return 0;
-  }
-
-  @Override
-  public void writeToParcel(Parcel dest, int flags) {
-    dest.writeInt(type);
-    dest.writeInt(trackIndex);
-  }
-
-  public static final Creator<RenditionKey> CREATOR =
-      new Creator<RenditionKey>() {
-        @Override
-        public RenditionKey createFromParcel(Parcel in) {
-          return new RenditionKey(in.readInt(), in.readInt());
-        }
-
-        @Override
-        public RenditionKey[] newArray(int size) {
-          return new RenditionKey[size];
-        }
-      };
 }

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/manifest/StreamKey.java

@@ -15,13 +15,11 @@
  */
 package com.google.android.exoplayer2.source.smoothstreaming.manifest;
 
-import android.os.Parcel;
-import android.os.Parcelable;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 /** Uniquely identifies a track in a {@link SsManifest}. */
-public final class StreamKey implements Parcelable, Comparable<StreamKey> {
+public final class StreamKey implements Comparable<StreamKey> {
 
   public final int streamElementIndex;
   public final int trackIndex;
@@ -66,30 +64,4 @@ public final class StreamKey implements Parcelable, Comparable<StreamKey> {
     }
     return result;
   }
-
-  // Parcelable implementation.
-
-  @Override
-  public int describeContents() {
-    return 0;
-  }
-
-  @Override
-  public void writeToParcel(Parcel dest, int flags) {
-    dest.writeInt(streamElementIndex);
-    dest.writeInt(trackIndex);
-  }
-
-  public static final Creator<StreamKey> CREATOR =
-      new Creator<StreamKey>() {
-        @Override
-        public StreamKey createFromParcel(Parcel in) {
-          return new StreamKey(in.readInt(), in.readInt());
-        }
-
-        @Override
-        public StreamKey[] newArray(int size) {
-          return new StreamKey[size];
-        }
-      };
 }

library/ui/src/main/res/values-hi/strings.xml

@@ -23,13 +23,13 @@
   <string name="exo_track_selection_title_text">लेख</string>
   <string name="exo_track_selection_none">कोई नहीं</string>
   <string name="exo_track_selection_auto">अपने आप</string>
-  <string name="exo_track_unknown">Unknown</string>
+  <string name="exo_track_unknown">अज्ञात</string>
   <string name="exo_track_resolution">%1$d × %2$d</string>
-  <string name="exo_track_mono">Mono</string>
-  <string name="exo_track_stereo">Stereo</string>
-  <string name="exo_track_surround">Surround sound</string>
-  <string name="exo_track_surround_5_point_1">5.1 surround sound</string>
-  <string name="exo_track_surround_7_point_1">7.1 surround sound</string>
-  <string name="exo_track_bitrate">%1$.2f Mbps</string>
+  <string name="exo_track_mono">मोनो साउंड</string>
+  <string name="exo_track_stereo">स्टीरियो साउंड</string>
+  <string name="exo_track_surround">सराउंड साउंड</string>
+  <string name="exo_track_surround_5_point_1">5.1 सराउंड साउंड</string>
+  <string name="exo_track_surround_7_point_1">7.1 सराउंड साउंड</string>
+  <string name="exo_track_bitrate">%1$.2f एमबीपीएस</string>
   <string name="exo_item_list">%1$s, %2$s</string>
 </resources>