Android歌词秀设计思路（5）歌词播放服务(4)

        return mLyricAdapter.getLyric(index); 
    } 
     
    public long seekToLyric(int index){ 
        long position = mLyricAdapter.getLyricTime(index); 
        if(position != -1){ 
            return seek(position); 
        }else{ 
            return 0; 
        } 
    } 
     
    public void seekToPrevLyric(){ 
        int curLyric =  mLyricAdapter.getCurrentLyric(); 
        if(curLyric > 0){ 
            seekToLyric(curLyric - 1); 
        } 
    } 
     
    public void seekToNextLyric(){ 
        int curLyric =  mLyricAdapter.getCurrentLyric(); 
        if(curLyric < mLyricAdapter.getLyricCount() - 1){ 
            seekToLyric(curLyric + 1); 
        } 
    }
所剩不多了，重载onCompletion是想在这个时刻关闭Timer的同时，将这一变化通知个mLyricPlayerListener.
@Override
public void onCompletion(MediaPlayer mp) { 
    if(mLyricTimer.isRunging()){ 
        mLyricTimer.stopTimer(); 
    } 
    if(mLyricPlayerListener != null){ 
        mLyricPlayerListener.onStateChanged(); 
    } 
    super.onCompletion(mp); 
}  
最后是继承LyricAdapter.LyricListener需要的两个方法。将来自LyricAdapter的通知转送给已经登录的mLyricPlayerLister。之所以这样做是希望利用者在使用时可以简单一些。
@Override
    public void onLyricChanged(int lyric_index){ 
        if(mLyricPlayerListener != null){ 
            mLyricPlayerListener.onLyricChanged(lyric_index); 
        } 
    } 
     
    @Override
    public void onLyricLoaded(){