Add exoplayer mediasession extension. Set player auto attributes.

app/build.gradle

@@ -77,6 +77,7 @@ dependencies {
     implementation 'com.google.android.exoplayer:exoplayer-dash:2.11.4'
     implementation 'com.google.android.exoplayer:exoplayer-ui:2.11.4'
     implementation 'com.google.android.exoplayer:extension-cast:2.11.4'
+    implementation 'com.google.android.exoplayer:extension-mediasession:2.11.4'
 
     implementation 'com.google.android:flexbox:2.0.1'
 

app/src/main/java/io/lbry/browser/MainActivity.java

@@ -7,6 +7,7 @@ import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.PictureInPictureParams;
 import android.content.BroadcastReceiver;
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
@@ -23,6 +24,7 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.provider.MediaStore;
+import android.support.v4.media.session.MediaSessionCompat;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.util.Base64;
@@ -40,6 +42,7 @@ import android.widget.Toast;
 
 import com.google.android.exoplayer2.SimpleExoPlayer;
 import com.google.android.exoplayer2.ext.cast.CastPlayer;
+import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector;
 import com.google.android.exoplayer2.ui.PlayerView;
 import com.google.android.exoplayer2.upstream.cache.Cache;
 import com.google.android.gms.cast.framework.CastContext;
@@ -67,6 +70,7 @@ import androidx.core.view.WindowInsetsCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
+import androidx.media.session.MediaButtonReceiver;
 import androidx.preference.PreferenceManager;
 import androidx.drawerlayout.widget.DrawerLayout;
 import androidx.appcompat.app.AppCompatActivity;
@@ -282,6 +286,7 @@ public class MainActivity extends AppCompatActivity implements SdkStatusListener
     private static boolean appStarted;
     private boolean serviceRunning;
     private CheckSdkReadyTask checkSdkReadyTask;
+    private MediaSessionCompat mediaSession;
     private boolean receivedStopService;
     private ActionBarDrawerToggle toggle;
     private SyncSetTask syncSetTask = null;
@@ -781,6 +786,9 @@ public class MainActivity extends AppCompatActivity implements SdkStatusListener
         if (dbHelper != null) {
             dbHelper.close();
         }
+        if (mediaSession != null) {
+            mediaSession.release();
+        }
         stopExoplayer();
         nowPlayingClaim = null;
         nowPlayingClaimUrl = null;
@@ -1413,6 +1421,14 @@ public class MainActivity extends AppCompatActivity implements SdkStatusListener
         initFloatingWalletBalance();
     }
 
+    public void initMediaSession() {
+        ComponentName mediaButtonReceiver = new ComponentName(getApplicationContext(), MediaButtonReceiver.class);
+        mediaSession = new MediaSessionCompat(getApplicationContext(), "LBRYMediaSession", mediaButtonReceiver, null);
+        MediaSessionConnector connector = new MediaSessionConnector(mediaSession);
+        connector.setPlayer(MainActivity.appPlayer);
+        mediaSession.setActive(true);
+    }
+
     public void showFloatingWalletBalance() {
         findViewById(R.id.floating_balance_main_container).setVisibility(View.VISIBLE);
     }

app/src/main/java/io/lbry/browser/ui/findcontent/FileViewFragment.java

@@ -3,6 +3,7 @@ package io.lbry.browser.ui.findcontent;
 import android.Manifest;
 import android.annotation.SuppressLint;
 import android.content.BroadcastReceiver;
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
@@ -12,6 +13,7 @@ import android.graphics.Color;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
+import android.support.v4.media.session.MediaSessionCompat;
 import android.text.format.DateUtils;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
@@ -32,6 +34,7 @@ import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.core.content.ContextCompat;
+import androidx.media.session.MediaButtonReceiver;
 import androidx.preference.PreferenceManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
@@ -42,7 +45,9 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.SimpleExoPlayer;
+import com.google.android.exoplayer2.audio.AudioAttributes;
 import com.google.android.exoplayer2.database.ExoDatabaseProvider;
+import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector;
 import com.google.android.exoplayer2.extractor.DefaultExtractorsFactory;
 import com.google.android.exoplayer2.source.MediaSource;
 import com.google.android.exoplayer2.source.ProgressiveMediaSource;
@@ -1213,8 +1218,20 @@ public class FileViewFragment extends BaseFragment implements
 
         Context context = getContext();
         if (MainActivity.appPlayer == null && context != null) {
+            AudioAttributes audioAttributes = new AudioAttributes.Builder()
+                    .setUsage(C.USAGE_MEDIA)
+                    .setContentType(C.CONTENT_TYPE_MOVIE)
+                    .build();
+
             MainActivity.appPlayer = new SimpleExoPlayer.Builder(context).build();
-            MainActivity.playerCache = new SimpleCache(context.getCacheDir(), new LeastRecentlyUsedCacheEvictor(1024 * 1024 * 256), new ExoDatabaseProvider(context));
+            MainActivity.appPlayer.setAudioAttributes(audioAttributes, true);
+            MainActivity.playerCache =
+                    new SimpleCache(context.getCacheDir(),
+                            new LeastRecentlyUsedCacheEvictor(1024 * 1024 * 256), new ExoDatabaseProvider(context));
+            if (context instanceof MainActivity) {
+                ((MainActivity) context).initMediaSession();
+            }
+
             newPlayerCreated = true;
         }