tree/demos/main/src/main/java/com/google/android/exoplayer2/demo/SampleChooserActivity.java - platform/external/exoplayer - Git at Google

 /*
  * Copyright (C) 2016 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.util.Assertions.checkNotNull;

 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.content.res.AssetManager;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.util.JsonReader;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.BaseExpandableListAdapter;
 import android.widget.ExpandableListView;
 import android.widget.ExpandableListView.OnChildClickListener;
 import android.widget.ImageButton;
 import android.widget.TextView;
 import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.MediaMetadata;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.RenderersFactory;
 import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSourceInputStream;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.DefaultDataSource;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;

 /** An activity for selecting from a list of media samples. */
 public class SampleChooserActivity extends AppCompatActivity
     implements DownloadTracker.Listener, OnChildClickListener {

   private static final String TAG = "SampleChooserActivity";
   private static final String GROUP_POSITION_PREFERENCE_KEY = "SAMPLE_CHOOSER_GROUP_POSITION";
   private static final String CHILD_POSITION_PREFERENCE_KEY = "SAMPLE_CHOOSER_CHILD_POSITION";

   private String[] uris;
   private boolean useExtensionRenderers;
   private DownloadTracker downloadTracker;
   private SampleAdapter sampleAdapter;
   private MenuItem preferExtensionDecodersMenuItem;
   private MenuItem randomAbrMenuItem;
   private MenuItem tunnelingMenuItem;
   private ExpandableListView sampleListView;

   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.sample_chooser_activity);
     sampleAdapter = new SampleAdapter();
     sampleListView = findViewById(R.id.sample_list);

     sampleListView.setAdapter(sampleAdapter);
     sampleListView.setOnChildClickListener(this);

     Intent intent = getIntent();
     String dataUri = intent.getDataString();
     if (dataUri != null) {
       uris = new String[] {dataUri};
     } else {
       ArrayList<String> uriList = new ArrayList<>();
       AssetManager assetManager = getAssets();
       try {
         for (String asset : assetManager.list("")) {
           if (asset.endsWith(".exolist.json")) {
             uriList.add("asset:///" + asset);
           }
         }
       } catch (IOException e) {
         Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
             .show();
       }
       uris = new String[uriList.size()];
       uriList.toArray(uris);
       Arrays.sort(uris);
     }

     DemoApplication application = (DemoApplication) getApplication();
     useExtensionRenderers = application.useExtensionRenderers();
     downloadTracker = application.getDownloadTracker();
     loadSample();

     // Start the download service if it should be running but it's not currently.
     // Starting the service in the foreground causes notification flicker if there is no scheduled
     // action. Starting it in the background throws an exception if the app is in the background too
     // (e.g. if device screen is locked).
     try {
       DownloadService.start(this, DemoDownloadService.class);
     } catch (IllegalStateException e) {
       DownloadService.startForeground(this, DemoDownloadService.class);
     }
   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
     MenuInflater inflater = getMenuInflater();
     inflater.inflate(R.menu.sample_chooser_menu, menu);
     preferExtensionDecodersMenuItem = menu.findItem(R.id.prefer_extension_decoders);
     preferExtensionDecodersMenuItem.setVisible(useExtensionRenderers);
     randomAbrMenuItem = menu.findItem(R.id.random_abr);
     tunnelingMenuItem = menu.findItem(R.id.tunneling);
     if (Util.SDK_INT < 21) {
       tunnelingMenuItem.setEnabled(false);
     }
     return true;
   }

   @Override
   public boolean onOptionsItemSelected(MenuItem item) {
     item.setChecked(!item.isChecked());
     return true;
   }

   @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();
   }

   @Override
   public void onRequestPermissionsResult(
       int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
     super.onRequestPermissionsResult(requestCode, permissions, grantResults);
     if (grantResults.length == 0) {
       // Empty results are triggered if a permission is requested while another request was already
       // pending and can be safely ignored in this case.
       return;
     }
     if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
       loadSample();
     } else {
       Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
           .show();
       finish();
     }
   }

   private void loadSample() {
     checkNotNull(uris);

     for (int i = 0; i < uris.length; i++) {
       Uri uri = Uri.parse(uris[i]);
       if (Util.maybeRequestReadExternalStoragePermission(this, uri)) {
         return;
       }
     }

     SampleListLoader loaderTask = new SampleListLoader();
     loaderTask.execute(uris);
   }

   private void onPlaylistGroups(final List<PlaylistGroup> groups, boolean sawError) {
     if (sawError) {
       Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
           .show();
     }
     sampleAdapter.setPlaylistGroups(groups);

     SharedPreferences preferences = getPreferences(MODE_PRIVATE);

     int groupPosition = -1;
     int childPosition = -1;
     try {
       groupPosition = preferences.getInt(GROUP_POSITION_PREFERENCE_KEY, /* defValue= */ -1);
       childPosition = preferences.getInt(CHILD_POSITION_PREFERENCE_KEY, /* defValue= */ -1);
     } catch (ClassCastException e) {
       Log.w(TAG, "Saved position is not an int. Will not restore position.", e);
     }
     if (groupPosition != -1 && childPosition != -1) {
       sampleListView.expandGroup(groupPosition); // shouldExpandGroup does not work without this.
       sampleListView.setSelectedChild(groupPosition, childPosition, /* shouldExpandGroup= */ true);
     }
   }

   @Override
   public boolean onChildClick(
       ExpandableListView parent, View view, int groupPosition, int childPosition, long id) {
     // Save the selected item first to be able to restore it if the tested code crashes.
     SharedPreferences.Editor prefEditor = getPreferences(MODE_PRIVATE).edit();
     prefEditor.putInt(GROUP_POSITION_PREFERENCE_KEY, groupPosition);
     prefEditor.putInt(CHILD_POSITION_PREFERENCE_KEY, childPosition);
     prefEditor.apply();

     PlaylistHolder playlistHolder = (PlaylistHolder) view.getTag();
     Intent intent = new Intent(this, PlayerActivity.class);
     intent.putExtra(
         IntentUtil.PREFER_EXTENSION_DECODERS_EXTRA,
         isNonNullAndChecked(preferExtensionDecodersMenuItem));
     String abrAlgorithm =
         isNonNullAndChecked(randomAbrMenuItem)
             ? IntentUtil.ABR_ALGORITHM_RANDOM
             : IntentUtil.ABR_ALGORITHM_DEFAULT;
     intent.putExtra(IntentUtil.ABR_ALGORITHM_EXTRA, abrAlgorithm);
     intent.putExtra(IntentUtil.TUNNELING_EXTRA, isNonNullAndChecked(tunnelingMenuItem));
     IntentUtil.addToIntent(playlistHolder.mediaItems, intent);
     startActivity(intent);
     return true;
   }

   private void onSampleDownloadButtonClicked(PlaylistHolder playlistHolder) {
     int downloadUnsupportedStringId = getDownloadUnsupportedStringId(playlistHolder);
     if (downloadUnsupportedStringId != 0) {
       Toast.makeText(getApplicationContext(), downloadUnsupportedStringId, Toast.LENGTH_LONG)
           .show();
     } else {
       RenderersFactory renderersFactory =
           ((DemoApplication) getApplication())
               .buildRenderersFactory(isNonNullAndChecked(preferExtensionDecodersMenuItem));
       downloadTracker.toggleDownload(
           getSupportFragmentManager(), playlistHolder.mediaItems.get(0), renderersFactory);
     }
   }

   private int getDownloadUnsupportedStringId(PlaylistHolder playlistHolder) {
     if (playlistHolder.mediaItems.size() > 1) {
       return R.string.download_playlist_unsupported;
     }
     MediaItem.PlaybackProperties playbackProperties =
         checkNotNull(playlistHolder.mediaItems.get(0).playbackProperties);
     if (playbackProperties.drmConfiguration != null) {
       return R.string.download_drm_unsupported;
     }
     if (((IntentUtil.Tag) checkNotNull(playbackProperties.tag)).isLive) {
       return R.string.download_live_unsupported;
     }
     if (playbackProperties.adTagUri != null) {
       return R.string.download_ads_unsupported;
     }
     String scheme = playbackProperties.sourceUri.getScheme();
     if (!("http".equals(scheme) || "https".equals(scheme))) {
       return R.string.download_scheme_unsupported;
     }
     return 0;
   }

   private static boolean isNonNullAndChecked(@Nullable MenuItem menuItem) {
     // Temporary workaround for layouts that do not inflate the options menu.
     return menuItem != null && menuItem.isChecked();
   }

   private final class SampleListLoader extends AsyncTask<String, Void, List<PlaylistGroup>> {

     private boolean sawError;

     @Override
     protected List<PlaylistGroup> doInBackground(String... uris) {
       List<PlaylistGroup> result = new ArrayList<>();
       Context context = getApplicationContext();
       String userAgent = Util.getUserAgent(context, "ExoPlayerDemo");
       DataSource dataSource =
           new DefaultDataSource(context, userAgent, /* allowCrossProtocolRedirects= */ false);
       for (String uri : uris) {
         DataSpec dataSpec = new DataSpec(Uri.parse(uri));
         InputStream inputStream = new DataSourceInputStream(dataSource, dataSpec);
         try {
           readPlaylistGroups(new JsonReader(new InputStreamReader(inputStream, "UTF-8")), result);
         } catch (Exception e) {
           Log.e(TAG, "Error loading sample list: " + uri, e);
           sawError = true;
         } finally {
           Util.closeQuietly(dataSource);
         }
       }
       return result;
     }

     @Override
     protected void onPostExecute(List<PlaylistGroup> result) {
       onPlaylistGroups(result, sawError);
     }

     private void readPlaylistGroups(JsonReader reader, List<PlaylistGroup> groups)
         throws IOException {
       reader.beginArray();
       while (reader.hasNext()) {
         readPlaylistGroup(reader, groups);
       }
       reader.endArray();
     }

     private void readPlaylistGroup(JsonReader reader, List<PlaylistGroup> groups)
         throws IOException {
       String groupName = "";
       ArrayList<PlaylistHolder> playlistHolders = new ArrayList<>();

       reader.beginObject();
       while (reader.hasNext()) {
         String name = reader.nextName();
         switch (name) {
           case "name":
             groupName = reader.nextString();
             break;
           case "samples":
             reader.beginArray();
             while (reader.hasNext()) {
               playlistHolders.add(readEntry(reader, false));
             }
             reader.endArray();
             break;
           case "_comment":
             reader.nextString(); // Ignore.
             break;
           default:
             throw new ParserException("Unsupported name: " + name);
         }
       }
       reader.endObject();

       PlaylistGroup group = getGroup(groupName, groups);
       group.playlists.addAll(playlistHolders);
     }

     private PlaylistHolder readEntry(JsonReader reader, boolean insidePlaylist) throws IOException {
       Uri uri = null;
       String extension = null;
       String title = null;
       boolean isLive = false;
       String sphericalStereoMode = null;
       ArrayList<PlaylistHolder> children = null;
       Uri subtitleUri = null;
       String subtitleMimeType = null;
       String subtitleLanguage = null;

       MediaItem.Builder mediaItem = new MediaItem.Builder();
       reader.beginObject();
       while (reader.hasNext()) {
         String name = reader.nextName();
         switch (name) {
           case "name":
             title = reader.nextString();
             break;
           case "uri":
             uri = Uri.parse(reader.nextString());
             break;
           case "extension":
             extension = reader.nextString();
             break;
           case "drm_scheme":
             mediaItem.setDrmUuid(Util.getDrmUuid(reader.nextString()));
             break;
           case "is_live":
             isLive = reader.nextBoolean();
             break;
           case "drm_license_url":
             mediaItem.setDrmLicenseUri(reader.nextString());
             break;
           case "drm_key_request_properties":
             Map<String, String> requestHeaders = new HashMap<>();
             reader.beginObject();
             while (reader.hasNext()) {
               requestHeaders.put(reader.nextName(), reader.nextString());
             }
             reader.endObject();
             mediaItem.setDrmLicenseRequestHeaders(requestHeaders);
             break;
           case "drm_session_for_clear_types":
             HashSet<Integer> drmSessionForClearTypes = new HashSet<>();
             reader.beginArray();
             while (reader.hasNext()) {
               drmSessionForClearTypes.add(toTrackType(reader.nextString()));
             }
             reader.endArray();
             mediaItem.setDrmSessionForClearTypes(new ArrayList<>(drmSessionForClearTypes));
             break;
           case "drm_multi_session":
             mediaItem.setDrmMultiSession(reader.nextBoolean());
             break;
           case "playlist":
             Assertions.checkState(!insidePlaylist, "Invalid nesting of playlists");
             children = new ArrayList<>();
             reader.beginArray();
             while (reader.hasNext()) {
               children.add(readEntry(reader, /* insidePlaylist= */ true));
             }
             reader.endArray();
             break;
           case "ad_tag_uri":
             mediaItem.setAdTagUri(reader.nextString());
             break;
           case "spherical_stereo_mode":
             Assertions.checkState(
                 !insidePlaylist, "Invalid attribute on nested item: spherical_stereo_mode");
             sphericalStereoMode = reader.nextString();
             break;
           case "subtitle_uri":
             subtitleUri = Uri.parse(reader.nextString());
             break;
           case "subtitle_mime_type":
             subtitleMimeType = reader.nextString();
             break;
           case "subtitle_language":
             subtitleLanguage = reader.nextString();
             break;
           default:
             throw new ParserException("Unsupported attribute name: " + name);
         }
       }
       reader.endObject();

       if (children != null) {
         List<MediaItem> mediaItems = new ArrayList<>();
         for (int i = 0; i < children.size(); i++) {
           mediaItems.addAll(children.get(i).mediaItems);
         }
         return new PlaylistHolder(title, mediaItems);
       } else {
         mediaItem
             .setSourceUri(uri)
             .setMediaMetadata(new MediaMetadata.Builder().setTitle(title).build())
             .setMimeType(IntentUtil.inferAdaptiveStreamMimeType(uri, extension))
             .setTag(new IntentUtil.Tag(isLive, sphericalStereoMode));
         if (subtitleUri != null) {
           MediaItem.Subtitle subtitle =
               new MediaItem.Subtitle(
                   subtitleUri,
                   checkNotNull(
                       subtitleMimeType, "subtitle_mime_type is required if subtitle_uri is set."),
                   subtitleLanguage);
           mediaItem.setSubtitles(Collections.singletonList(subtitle));
         }
         return new PlaylistHolder(title, Collections.singletonList(mediaItem.build()));
       }
     }

     private PlaylistGroup getGroup(String groupName, List<PlaylistGroup> groups) {
       for (int i = 0; i < groups.size(); i++) {
         if (Util.areEqual(groupName, groups.get(i).title)) {
           return groups.get(i);
         }
       }
       PlaylistGroup group = new PlaylistGroup(groupName);
       groups.add(group);
       return group;
     }

     private int toTrackType(String trackTypeString) {
       switch (Util.toLowerInvariant(trackTypeString)) {
         case "audio":
           return C.TRACK_TYPE_AUDIO;
         case "video":
           return C.TRACK_TYPE_VIDEO;
         default:
           throw new IllegalArgumentException("Invalid track type: " + trackTypeString);
       }
     }
   }

   private final class SampleAdapter extends BaseExpandableListAdapter implements OnClickListener {

     private List<PlaylistGroup> playlistGroups;

     public SampleAdapter() {
       playlistGroups = Collections.emptyList();
     }

     public void setPlaylistGroups(List<PlaylistGroup> playlistGroups) {
       this.playlistGroups = playlistGroups;
       notifyDataSetChanged();
     }

     @Override
     public PlaylistHolder getChild(int groupPosition, int childPosition) {
       return getGroup(groupPosition).playlists.get(childPosition);
     }

     @Override
     public long getChildId(int groupPosition, int childPosition) {
       return childPosition;
     }

     @Override
     public View getChildView(
         int groupPosition,
         int childPosition,
         boolean isLastChild,
         View convertView,
         ViewGroup parent) {
       View view = convertView;
       if (view == null) {
         view = getLayoutInflater().inflate(R.layout.sample_list_item, parent, false);
         View downloadButton = view.findViewById(R.id.download_button);
         downloadButton.setOnClickListener(this);
         downloadButton.setFocusable(false);
       }
       initializeChildView(view, getChild(groupPosition, childPosition));
       return view;
     }

     @Override
     public int getChildrenCount(int groupPosition) {
       return getGroup(groupPosition).playlists.size();
     }

     @Override
     public PlaylistGroup getGroup(int groupPosition) {
       return playlistGroups.get(groupPosition);
     }

     @Override
     public long getGroupId(int groupPosition) {
       return groupPosition;
     }

     @Override
     public View getGroupView(
         int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
       View view = convertView;
       if (view == null) {
         view =
             getLayoutInflater()
                 .inflate(android.R.layout.simple_expandable_list_item_1, parent, false);
       }
       ((TextView) view).setText(getGroup(groupPosition).title);
       return view;
     }

     @Override
     public int getGroupCount() {
       return playlistGroups.size();
     }

     @Override
     public boolean hasStableIds() {
       return false;
     }

     @Override
     public boolean isChildSelectable(int groupPosition, int childPosition) {
       return true;
     }

     @Override
     public void onClick(View view) {
       onSampleDownloadButtonClicked((PlaylistHolder) view.getTag());
     }

     private void initializeChildView(View view, PlaylistHolder playlistHolder) {
       view.setTag(playlistHolder);
       TextView sampleTitle = view.findViewById(R.id.sample_title);
       sampleTitle.setText(playlistHolder.title);

       boolean canDownload = getDownloadUnsupportedStringId(playlistHolder) == 0;
       boolean isDownloaded =
           canDownload && downloadTracker.isDownloaded(playlistHolder.mediaItems.get(0));
       ImageButton downloadButton = view.findViewById(R.id.download_button);
       downloadButton.setTag(playlistHolder);
       downloadButton.setColorFilter(
           canDownload ? (isDownloaded ? 0xFF42A5F5 : 0xFFBDBDBD) : 0xFF666666);
       downloadButton.setImageResource(
           isDownloaded ? R.drawable.ic_download_done : R.drawable.ic_download);
     }
   }

   private static final class PlaylistHolder {

     public final String title;
     public final List<MediaItem> mediaItems;

     private PlaylistHolder(String title, List<MediaItem> mediaItems) {
       Assertions.checkArgument(!mediaItems.isEmpty());
       this.title = title;
       this.mediaItems = Collections.unmodifiableList(new ArrayList<>(mediaItems));
     }
   }

   private static final class PlaylistGroup {

     public final String title;
     public final List<PlaylistHolder> playlists;

     public PlaylistGroup(String title) {
       this.title = title;
       this.playlists = new ArrayList<>();
     }
   }
 }
	/*
	* Copyright (C) 2016 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.util.Assertions.checkNotNull;

	import android.content.Context;
	import android.content.Intent;
	import android.content.SharedPreferences;
	import android.content.pm.PackageManager;
	import android.content.pm.ResolveInfo;
	import android.content.res.AssetManager;
	import android.net.Uri;
	import android.os.AsyncTask;
	import android.os.Bundle;
	import android.util.JsonReader;
	import android.view.Menu;
	import android.view.MenuInflater;
	import android.view.MenuItem;
	import android.view.View;
	import android.view.View.OnClickListener;
	import android.view.ViewGroup;
	import android.widget.BaseExpandableListAdapter;
	import android.widget.ExpandableListView;
	import android.widget.ExpandableListView.OnChildClickListener;
	import android.widget.ImageButton;
	import android.widget.TextView;
	import android.widget.Toast;
	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.appcompat.app.AppCompatActivity;
	import com.google.android.exoplayer2.C;
	import com.google.android.exoplayer2.MediaItem;
	import com.google.android.exoplayer2.MediaMetadata;
	import com.google.android.exoplayer2.ParserException;
	import com.google.android.exoplayer2.RenderersFactory;
	import com.google.android.exoplayer2.offline.DownloadService;
	import com.google.android.exoplayer2.upstream.DataSource;
	import com.google.android.exoplayer2.upstream.DataSourceInputStream;
	import com.google.android.exoplayer2.upstream.DataSpec;
	import com.google.android.exoplayer2.upstream.DefaultDataSource;
	import com.google.android.exoplayer2.util.Assertions;
	import com.google.android.exoplayer2.util.Log;
	import com.google.android.exoplayer2.util.Util;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;

	/** An activity for selecting from a list of media samples. */
	public class SampleChooserActivity extends AppCompatActivity
	implements DownloadTracker.Listener, OnChildClickListener {

	private static final String TAG = "SampleChooserActivity";
	private static final String GROUP_POSITION_PREFERENCE_KEY = "SAMPLE_CHOOSER_GROUP_POSITION";
	private static final String CHILD_POSITION_PREFERENCE_KEY = "SAMPLE_CHOOSER_CHILD_POSITION";

	private String[] uris;
	private boolean useExtensionRenderers;
	private DownloadTracker downloadTracker;
	private SampleAdapter sampleAdapter;
	private MenuItem preferExtensionDecodersMenuItem;
	private MenuItem randomAbrMenuItem;
	private MenuItem tunnelingMenuItem;
	private ExpandableListView sampleListView;

	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.sample_chooser_activity);
	sampleAdapter = new SampleAdapter();
	sampleListView = findViewById(R.id.sample_list);

	sampleListView.setAdapter(sampleAdapter);
	sampleListView.setOnChildClickListener(this);

	Intent intent = getIntent();
	String dataUri = intent.getDataString();
	if (dataUri != null) {
	uris = new String[] {dataUri};
	} else {
	ArrayList<String> uriList = new ArrayList<>();
	AssetManager assetManager = getAssets();
	try {
	for (String asset : assetManager.list("")) {
	if (asset.endsWith(".exolist.json")) {
	uriList.add("asset:///" + asset);
	}
	}
	} catch (IOException e) {
	Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
	.show();
	}
	uris = new String[uriList.size()];
	uriList.toArray(uris);
	Arrays.sort(uris);
	}

	DemoApplication application = (DemoApplication) getApplication();
	useExtensionRenderers = application.useExtensionRenderers();
	downloadTracker = application.getDownloadTracker();
	loadSample();

	// Start the download service if it should be running but it's not currently.
	// Starting the service in the foreground causes notification flicker if there is no scheduled
	// action. Starting it in the background throws an exception if the app is in the background too
	// (e.g. if device screen is locked).
	try {
	DownloadService.start(this, DemoDownloadService.class);
	} catch (IllegalStateException e) {
	DownloadService.startForeground(this, DemoDownloadService.class);
	}
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
	MenuInflater inflater = getMenuInflater();
	inflater.inflate(R.menu.sample_chooser_menu, menu);
	preferExtensionDecodersMenuItem = menu.findItem(R.id.prefer_extension_decoders);
	preferExtensionDecodersMenuItem.setVisible(useExtensionRenderers);
	randomAbrMenuItem = menu.findItem(R.id.random_abr);
	tunnelingMenuItem = menu.findItem(R.id.tunneling);
	if (Util.SDK_INT < 21) {
	tunnelingMenuItem.setEnabled(false);
	}
	return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
	item.setChecked(!item.isChecked());
	return true;
	}

	@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();
	}

	@Override
	public void onRequestPermissionsResult(
	int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
	super.onRequestPermissionsResult(requestCode, permissions, grantResults);
	if (grantResults.length == 0) {
	// Empty results are triggered if a permission is requested while another request was already
	// pending and can be safely ignored in this case.
	return;
	}
	if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
	loadSample();
	} else {
	Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
	.show();
	finish();
	}
	}

	private void loadSample() {
	checkNotNull(uris);

	for (int i = 0; i < uris.length; i++) {
	Uri uri = Uri.parse(uris[i]);
	if (Util.maybeRequestReadExternalStoragePermission(this, uri)) {
	return;
	}
	}

	SampleListLoader loaderTask = new SampleListLoader();
	loaderTask.execute(uris);
	}

	private void onPlaylistGroups(final List<PlaylistGroup> groups, boolean sawError) {
	if (sawError) {
	Toast.makeText(getApplicationContext(), R.string.sample_list_load_error, Toast.LENGTH_LONG)
	.show();
	}
	sampleAdapter.setPlaylistGroups(groups);

	SharedPreferences preferences = getPreferences(MODE_PRIVATE);

	int groupPosition = -1;
	int childPosition = -1;
	try {
	groupPosition = preferences.getInt(GROUP_POSITION_PREFERENCE_KEY, /* defValue= */ -1);
	childPosition = preferences.getInt(CHILD_POSITION_PREFERENCE_KEY, /* defValue= */ -1);
	} catch (ClassCastException e) {
	Log.w(TAG, "Saved position is not an int. Will not restore position.", e);
	}
	if (groupPosition != -1 && childPosition != -1) {
	sampleListView.expandGroup(groupPosition); // shouldExpandGroup does not work without this.
	sampleListView.setSelectedChild(groupPosition, childPosition, /* shouldExpandGroup= */ true);
	}
	}

	@Override
	public boolean onChildClick(
	ExpandableListView parent, View view, int groupPosition, int childPosition, long id) {
	// Save the selected item first to be able to restore it if the tested code crashes.
	SharedPreferences.Editor prefEditor = getPreferences(MODE_PRIVATE).edit();
	prefEditor.putInt(GROUP_POSITION_PREFERENCE_KEY, groupPosition);
	prefEditor.putInt(CHILD_POSITION_PREFERENCE_KEY, childPosition);
	prefEditor.apply();

	PlaylistHolder playlistHolder = (PlaylistHolder) view.getTag();
	Intent intent = new Intent(this, PlayerActivity.class);
	intent.putExtra(
	IntentUtil.PREFER_EXTENSION_DECODERS_EXTRA,
	isNonNullAndChecked(preferExtensionDecodersMenuItem));
	String abrAlgorithm =
	isNonNullAndChecked(randomAbrMenuItem)
	? IntentUtil.ABR_ALGORITHM_RANDOM
	: IntentUtil.ABR_ALGORITHM_DEFAULT;
	intent.putExtra(IntentUtil.ABR_ALGORITHM_EXTRA, abrAlgorithm);
	intent.putExtra(IntentUtil.TUNNELING_EXTRA, isNonNullAndChecked(tunnelingMenuItem));
	IntentUtil.addToIntent(playlistHolder.mediaItems, intent);
	startActivity(intent);
	return true;
	}

	private void onSampleDownloadButtonClicked(PlaylistHolder playlistHolder) {
	int downloadUnsupportedStringId = getDownloadUnsupportedStringId(playlistHolder);
	if (downloadUnsupportedStringId != 0) {
	Toast.makeText(getApplicationContext(), downloadUnsupportedStringId, Toast.LENGTH_LONG)
	.show();
	} else {
	RenderersFactory renderersFactory =
	((DemoApplication) getApplication())
	.buildRenderersFactory(isNonNullAndChecked(preferExtensionDecodersMenuItem));
	downloadTracker.toggleDownload(
	getSupportFragmentManager(), playlistHolder.mediaItems.get(0), renderersFactory);
	}
	}

	private int getDownloadUnsupportedStringId(PlaylistHolder playlistHolder) {
	if (playlistHolder.mediaItems.size() > 1) {
	return R.string.download_playlist_unsupported;
	}
	MediaItem.PlaybackProperties playbackProperties =
	checkNotNull(playlistHolder.mediaItems.get(0).playbackProperties);
	if (playbackProperties.drmConfiguration != null) {
	return R.string.download_drm_unsupported;
	}
	if (((IntentUtil.Tag) checkNotNull(playbackProperties.tag)).isLive) {
	return R.string.download_live_unsupported;
	}
	if (playbackProperties.adTagUri != null) {
	return R.string.download_ads_unsupported;
	}
	String scheme = playbackProperties.sourceUri.getScheme();
	if (!("http".equals(scheme) \|\| "https".equals(scheme))) {
	return R.string.download_scheme_unsupported;
	}
	return 0;
	}

	private static boolean isNonNullAndChecked(@Nullable MenuItem menuItem) {
	// Temporary workaround for layouts that do not inflate the options menu.
	return menuItem != null && menuItem.isChecked();
	}

	private final class SampleListLoader extends AsyncTask<String, Void, List<PlaylistGroup>> {

	private boolean sawError;

	@Override
	protected List<PlaylistGroup> doInBackground(String... uris) {
	List<PlaylistGroup> result = new ArrayList<>();
	Context context = getApplicationContext();
	String userAgent = Util.getUserAgent(context, "ExoPlayerDemo");
	DataSource dataSource =
	new DefaultDataSource(context, userAgent, /* allowCrossProtocolRedirects= */ false);
	for (String uri : uris) {
	DataSpec dataSpec = new DataSpec(Uri.parse(uri));
	InputStream inputStream = new DataSourceInputStream(dataSource, dataSpec);
	try {
	readPlaylistGroups(new JsonReader(new InputStreamReader(inputStream, "UTF-8")), result);
	} catch (Exception e) {
	Log.e(TAG, "Error loading sample list: " + uri, e);
	sawError = true;
	} finally {
	Util.closeQuietly(dataSource);
	}
	}
	return result;
	}

	@Override
	protected void onPostExecute(List<PlaylistGroup> result) {
	onPlaylistGroups(result, sawError);
	}

	private void readPlaylistGroups(JsonReader reader, List<PlaylistGroup> groups)
	throws IOException {
	reader.beginArray();
	while (reader.hasNext()) {
	readPlaylistGroup(reader, groups);
	}
	reader.endArray();
	}

	private void readPlaylistGroup(JsonReader reader, List<PlaylistGroup> groups)
	throws IOException {
	String groupName = "";
	ArrayList<PlaylistHolder> playlistHolders = new ArrayList<>();

	reader.beginObject();
	while (reader.hasNext()) {
	String name = reader.nextName();
	switch (name) {
	case "name":
	groupName = reader.nextString();
	break;
	case "samples":
	reader.beginArray();
	while (reader.hasNext()) {
	playlistHolders.add(readEntry(reader, false));
	}
	reader.endArray();
	break;
	case "_comment":
	reader.nextString(); // Ignore.
	break;
	default:
	throw new ParserException("Unsupported name: " + name);
	}
	}
	reader.endObject();

	PlaylistGroup group = getGroup(groupName, groups);
	group.playlists.addAll(playlistHolders);
	}

	private PlaylistHolder readEntry(JsonReader reader, boolean insidePlaylist) throws IOException {
	Uri uri = null;
	String extension = null;
	String title = null;
	boolean isLive = false;
	String sphericalStereoMode = null;
	ArrayList<PlaylistHolder> children = null;
	Uri subtitleUri = null;
	String subtitleMimeType = null;
	String subtitleLanguage = null;

	MediaItem.Builder mediaItem = new MediaItem.Builder();
	reader.beginObject();
	while (reader.hasNext()) {
	String name = reader.nextName();
	switch (name) {
	case "name":
	title = reader.nextString();
	break;
	case "uri":
	uri = Uri.parse(reader.nextString());
	break;
	case "extension":
	extension = reader.nextString();
	break;
	case "drm_scheme":
	mediaItem.setDrmUuid(Util.getDrmUuid(reader.nextString()));
	break;
	case "is_live":
	isLive = reader.nextBoolean();
	break;
	case "drm_license_url":
	mediaItem.setDrmLicenseUri(reader.nextString());
	break;
	case "drm_key_request_properties":
	Map<String, String> requestHeaders = new HashMap<>();
	reader.beginObject();
	while (reader.hasNext()) {
	requestHeaders.put(reader.nextName(), reader.nextString());
	}
	reader.endObject();
	mediaItem.setDrmLicenseRequestHeaders(requestHeaders);
	break;
	case "drm_session_for_clear_types":
	HashSet<Integer> drmSessionForClearTypes = new HashSet<>();
	reader.beginArray();
	while (reader.hasNext()) {
	drmSessionForClearTypes.add(toTrackType(reader.nextString()));
	}
	reader.endArray();
	mediaItem.setDrmSessionForClearTypes(new ArrayList<>(drmSessionForClearTypes));
	break;
	case "drm_multi_session":
	mediaItem.setDrmMultiSession(reader.nextBoolean());
	break;
	case "playlist":
	Assertions.checkState(!insidePlaylist, "Invalid nesting of playlists");
	children = new ArrayList<>();
	reader.beginArray();
	while (reader.hasNext()) {
	children.add(readEntry(reader, /* insidePlaylist= */ true));
	}
	reader.endArray();
	break;
	case "ad_tag_uri":
	mediaItem.setAdTagUri(reader.nextString());
	break;
	case "spherical_stereo_mode":
	Assertions.checkState(
	!insidePlaylist, "Invalid attribute on nested item: spherical_stereo_mode");
	sphericalStereoMode = reader.nextString();
	break;
	case "subtitle_uri":
	subtitleUri = Uri.parse(reader.nextString());
	break;
	case "subtitle_mime_type":
	subtitleMimeType = reader.nextString();
	break;
	case "subtitle_language":
	subtitleLanguage = reader.nextString();
	break;
	default:
	throw new ParserException("Unsupported attribute name: " + name);
	}
	}
	reader.endObject();

	if (children != null) {
	List<MediaItem> mediaItems = new ArrayList<>();
	for (int i = 0; i < children.size(); i++) {
	mediaItems.addAll(children.get(i).mediaItems);
	}
	return new PlaylistHolder(title, mediaItems);
	} else {
	mediaItem
	.setSourceUri(uri)
	.setMediaMetadata(new MediaMetadata.Builder().setTitle(title).build())
	.setMimeType(IntentUtil.inferAdaptiveStreamMimeType(uri, extension))
	.setTag(new IntentUtil.Tag(isLive, sphericalStereoMode));
	if (subtitleUri != null) {
	MediaItem.Subtitle subtitle =
	new MediaItem.Subtitle(
	subtitleUri,
	checkNotNull(
	subtitleMimeType, "subtitle_mime_type is required if subtitle_uri is set."),
	subtitleLanguage);
	mediaItem.setSubtitles(Collections.singletonList(subtitle));
	}
	return new PlaylistHolder(title, Collections.singletonList(mediaItem.build()));
	}
	}

	private PlaylistGroup getGroup(String groupName, List<PlaylistGroup> groups) {
	for (int i = 0; i < groups.size(); i++) {
	if (Util.areEqual(groupName, groups.get(i).title)) {
	return groups.get(i);
	}
	}
	PlaylistGroup group = new PlaylistGroup(groupName);
	groups.add(group);
	return group;
	}

	private int toTrackType(String trackTypeString) {
	switch (Util.toLowerInvariant(trackTypeString)) {
	case "audio":
	return C.TRACK_TYPE_AUDIO;
	case "video":
	return C.TRACK_TYPE_VIDEO;
	default:
	throw new IllegalArgumentException("Invalid track type: " + trackTypeString);
	}
	}
	}

	private final class SampleAdapter extends BaseExpandableListAdapter implements OnClickListener {

	private List<PlaylistGroup> playlistGroups;

	public SampleAdapter() {
	playlistGroups = Collections.emptyList();
	}

	public void setPlaylistGroups(List<PlaylistGroup> playlistGroups) {
	this.playlistGroups = playlistGroups;
	notifyDataSetChanged();
	}

	@Override
	public PlaylistHolder getChild(int groupPosition, int childPosition) {
	return getGroup(groupPosition).playlists.get(childPosition);
	}

	@Override
	public long getChildId(int groupPosition, int childPosition) {
	return childPosition;
	}

	@Override
	public View getChildView(
	int groupPosition,
	int childPosition,
	boolean isLastChild,
	View convertView,
	ViewGroup parent) {
	View view = convertView;
	if (view == null) {
	view = getLayoutInflater().inflate(R.layout.sample_list_item, parent, false);
	View downloadButton = view.findViewById(R.id.download_button);
	downloadButton.setOnClickListener(this);
	downloadButton.setFocusable(false);
	}
	initializeChildView(view, getChild(groupPosition, childPosition));
	return view;
	}

	@Override
	public int getChildrenCount(int groupPosition) {
	return getGroup(groupPosition).playlists.size();
	}

	@Override
	public PlaylistGroup getGroup(int groupPosition) {
	return playlistGroups.get(groupPosition);
	}

	@Override
	public long getGroupId(int groupPosition) {
	return groupPosition;
	}

	@Override
	public View getGroupView(
	int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
	View view = convertView;
	if (view == null) {
	view =
	getLayoutInflater()
	.inflate(android.R.layout.simple_expandable_list_item_1, parent, false);
	}
	((TextView) view).setText(getGroup(groupPosition).title);
	return view;
	}

	@Override
	public int getGroupCount() {
	return playlistGroups.size();
	}

	@Override
	public boolean hasStableIds() {
	return false;
	}

	@Override
	public boolean isChildSelectable(int groupPosition, int childPosition) {
	return true;
	}

	@Override
	public void onClick(View view) {
	onSampleDownloadButtonClicked((PlaylistHolder) view.getTag());
	}

	private void initializeChildView(View view, PlaylistHolder playlistHolder) {
	view.setTag(playlistHolder);
	TextView sampleTitle = view.findViewById(R.id.sample_title);
	sampleTitle.setText(playlistHolder.title);

	boolean canDownload = getDownloadUnsupportedStringId(playlistHolder) == 0;
	boolean isDownloaded =
	canDownload && downloadTracker.isDownloaded(playlistHolder.mediaItems.get(0));
	ImageButton downloadButton = view.findViewById(R.id.download_button);
	downloadButton.setTag(playlistHolder);
	downloadButton.setColorFilter(
	canDownload ? (isDownloaded ? 0xFF42A5F5 : 0xFFBDBDBD) : 0xFF666666);
	downloadButton.setImageResource(
	isDownloaded ? R.drawable.ic_download_done : R.drawable.ic_download);
	}
	}

	private static final class PlaylistHolder {

	public final String title;
	public final List<MediaItem> mediaItems;

	private PlaylistHolder(String title, List<MediaItem> mediaItems) {
	Assertions.checkArgument(!mediaItems.isEmpty());
	this.title = title;
	this.mediaItems = Collections.unmodifiableList(new ArrayList<>(mediaItems));
	}
	}

	private static final class PlaylistGroup {

	public final String title;
	public final List<PlaylistHolder> playlists;

	public PlaylistGroup(String title) {
	this.title = title;
	this.playlists = new ArrayList<>();
	}
	}
	}