--- /dev/null
+/*
+ * Copyright 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.moiseum.wolnelektury.view.player.service;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.os.Bundle;
+import android.os.RemoteException;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.media.MediaBrowserCompat;
+import android.support.v4.media.MediaBrowserServiceCompat;
+import android.support.v4.media.MediaMetadataCompat;
+import android.support.v4.media.session.MediaControllerCompat;
+import android.support.v4.media.session.MediaControllerCompat.Callback;
+import android.support.v4.media.session.MediaSessionCompat;
+import android.support.v4.media.session.PlaybackStateCompat;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Helper class for a MediaBrowser that handles connecting, disconnecting,
+ * and basic browsing with simplified callbacks.
+ */
+public class MediaBrowserHelper {
+
+ private static final String TAG = MediaBrowserHelper.class.getSimpleName();
+
+ private final Context mContext;
+ private final Class<? extends MediaBrowserServiceCompat> mMediaBrowserServiceClass;
+
+ private final List<Callback> mCallbackList = new ArrayList<>();
+
+ private final MediaBrowserConnectionCallback mMediaBrowserConnectionCallback;
+ private final MediaControllerCallback mMediaControllerCallback;
+ private final MediaBrowserSubscriptionCallback mMediaBrowserSubscriptionCallback;
+
+ private MediaBrowserCompat mMediaBrowser;
+
+ @Nullable
+ private MediaControllerCompat mMediaController;
+
+ public MediaBrowserHelper(Context context,
+ Class<? extends MediaBrowserServiceCompat> serviceClass) {
+ mContext = context;
+ mMediaBrowserServiceClass = serviceClass;
+
+ mMediaBrowserConnectionCallback = new MediaBrowserConnectionCallback();
+ mMediaControllerCallback = new MediaControllerCallback();
+ mMediaBrowserSubscriptionCallback = new MediaBrowserSubscriptionCallback();
+ }
+
+ public void onStart() {
+ if (mMediaBrowser == null) {
+ mMediaBrowser =
+ new MediaBrowserCompat(
+ mContext,
+ new ComponentName(mContext, mMediaBrowserServiceClass),
+ mMediaBrowserConnectionCallback,
+ null);
+ mMediaBrowser.connect();
+ }
+ Log.d(TAG, "onStart: Creating MediaBrowser, and connecting");
+ }
+
+ public void onStop() {
+ if (mMediaController != null) {
+ mMediaController.unregisterCallback(mMediaControllerCallback);
+ mMediaController = null;
+ }
+ if (mMediaBrowser != null && mMediaBrowser.isConnected()) {
+ mMediaBrowser.disconnect();
+ mMediaBrowser = null;
+ }
+ resetState();
+ Log.d(TAG, "onStop: Releasing MediaController, Disconnecting from MediaBrowser");
+ }
+
+ /**
+ * Called after connecting with a {@link MediaBrowserServiceCompat}.
+ * <p>
+ * Override to perform processing after a connection is established.
+ *
+ * @param mediaController {@link MediaControllerCompat} associated with the connected
+ * MediaSession.
+ */
+ protected void onConnected(@NonNull MediaControllerCompat mediaController) {
+ }
+
+ /**
+ * Called after loading a browsable {@link MediaBrowserCompat.MediaItem}
+ *
+ * @param parentId The media ID of the parent item.
+ * @param children List (possibly empty) of child items.
+ */
+ protected void onChildrenLoaded(@NonNull String parentId,
+ @NonNull List<MediaBrowserCompat.MediaItem> children) {
+ }
+
+ /**
+ * Called when the {@link MediaBrowserServiceCompat} connection is lost.
+ */
+ protected void onDisconnected() {
+ }
+
+ @NonNull
+ protected final MediaControllerCompat getMediaController() {
+ if (mMediaController == null) {
+ throw new IllegalStateException("MediaController is null!");
+ }
+ return mMediaController;
+ }
+
+ /**
+ * The internal state of the app needs to revert to what it looks like when it started before
+ * any connections to the {@link AudiobookService} happens via the {@link MediaSessionCompat}.
+ */
+ private void resetState() {
+ performOnAllCallbacks(callback -> callback.onPlaybackStateChanged(null));
+ Log.d(TAG, "resetState: ");
+ }
+
+ public MediaControllerCompat.TransportControls getTransportControls() {
+ if (mMediaController == null) {
+ Log.d(TAG, "getTransportControls: MediaController is null!");
+ throw new IllegalStateException("MediaController is null!");
+ }
+ return mMediaController.getTransportControls();
+ }
+
+ public void registerCallback(Callback callback) {
+ if (callback != null) {
+ mCallbackList.add(callback);
+
+ // Update with the latest metadata/playback state.
+ if (mMediaController != null) {
+ final MediaMetadataCompat metadata = mMediaController.getMetadata();
+ if (metadata != null) {
+ callback.onMetadataChanged(metadata);
+ }
+
+ final PlaybackStateCompat playbackState = mMediaController.getPlaybackState();
+ if (playbackState != null) {
+ callback.onPlaybackStateChanged(playbackState);
+ }
+ }
+ }
+ }
+
+ private void performOnAllCallbacks(@NonNull CallbackCommand command) {
+ for (Callback callback : mCallbackList) {
+ if (callback != null) {
+ command.perform(callback);
+ }
+ }
+ }
+
+ /**
+ * Helper for more easily performing operations on all listening clients.
+ */
+ private interface CallbackCommand {
+ void perform(@NonNull Callback callback);
+ }
+
+ // Receives callbacks from the MediaBrowser when it has successfully connected to the
+ // MediaBrowserService (AudiobookService).
+ private class MediaBrowserConnectionCallback extends MediaBrowserCompat.ConnectionCallback {
+
+ // Happens as a result of onStart().
+ @Override
+ public void onConnected() {
+ try {
+ // Get a MediaController for the MediaSession.
+ mMediaController =
+ new MediaControllerCompat(mContext, mMediaBrowser.getSessionToken());
+ mMediaController.registerCallback(mMediaControllerCallback);
+
+ // Sync existing MediaSession state to the UI.
+ mMediaControllerCallback.onMetadataChanged(mMediaController.getMetadata());
+ mMediaControllerCallback.onPlaybackStateChanged(
+ mMediaController.getPlaybackState());
+
+ MediaBrowserHelper.this.onConnected(mMediaController);
+ } catch (RemoteException e) {
+ Log.d(TAG, String.format("onConnected: Problem: %s", e.toString()));
+ throw new RuntimeException(e);
+ }
+
+ mMediaBrowser.subscribe(mMediaBrowser.getRoot(), mMediaBrowserSubscriptionCallback);
+ }
+ }
+
+ // Receives callbacks from the MediaBrowser when the MediaBrowserService has loaded new media
+ // that is ready for playback.
+ public class MediaBrowserSubscriptionCallback extends MediaBrowserCompat.SubscriptionCallback {
+
+ @Override
+ public void onChildrenLoaded(@NonNull String parentId,
+ @NonNull List<MediaBrowserCompat.MediaItem> children) {
+ MediaBrowserHelper.this.onChildrenLoaded(parentId, children);
+ }
+ }
+
+ // Receives callbacks from the MediaController and updates the UI state,
+ // i.e.: Which is the current item, whether it's playing or paused, etc.
+ private class MediaControllerCallback extends MediaControllerCompat.Callback {
+
+ @Override
+ public void onMetadataChanged(final MediaMetadataCompat metadata) {
+ performOnAllCallbacks(callback -> callback.onMetadataChanged(metadata));
+ }
+
+ @Override
+ public void onPlaybackStateChanged(@Nullable final PlaybackStateCompat state) {
+ performOnAllCallbacks(callback -> callback.onPlaybackStateChanged(state));
+ }
+
+ @Override
+ public void onExtrasChanged(Bundle extras) {
+ performOnAllCallbacks(callback -> callback.onExtrasChanged(extras));
+ }
+
+ // This might happen if the AudiobookService is killed while the Activity is in the
+ // foreground and onStart() has been called (but not onStop()).
+ @Override
+ public void onSessionDestroyed() {
+ resetState();
+ onPlaybackStateChanged(null);
+
+ MediaBrowserHelper.this.onDisconnected();
+ }
+ }
+}
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fnp / wl-app.git / blobdiff