| /* |
| * Copyright 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.android.car.media.common.playback; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.media.MediaMetadata; |
| import android.media.session.MediaController; |
| |
| import androidx.lifecycle.LiveData; |
| |
| /** |
| * Watches the {@link MediaMetadata} for the session controlled by given a {@link MediaController}. |
| * |
| * @see MediaController#getMetadata() |
| */ |
| class MediaMetadataLiveData extends LiveData<MediaMetadata> { |
| |
| private final MediaController mMediaController; |
| private final MediaController.Callback mCallback = new MediaController.Callback() { |
| @Override |
| public void onMetadataChanged(@Nullable MediaMetadata metadata) { |
| setValue(metadata); |
| } |
| }; |
| |
| MediaMetadataLiveData(@NonNull MediaController mediaController) { |
| mMediaController = mediaController; |
| } |
| |
| @Override |
| protected void onActive() { |
| mMediaController.registerCallback(mCallback); |
| } |
| |
| @Override |
| protected void onInactive() { |
| mMediaController.unregisterCallback(mCallback); |
| } |
| } |