Android 手机影音 开发过程记录（六）

前一篇已经将音乐播放及切换的相关逻辑弄好了，今天主要理一下剩余的部分，包括：
1. 自定义通知栏的布局及逻辑处理
2. 滚动歌词的绘制
3. 歌词解析

效果图

通知栏

1. 自定义布局：

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:id="@+id/layout_notification" android:padding="10dp" >
   
       <ImageView  android:layout_width="40dp" android:layout_height="40dp" android:background="@mipmap/ic_launcher" />
   
       <LinearLayout  android:layout_width="0dp" android:layout_height="40dp" android:layout_weight="1" android:layout_marginLeft="10dp" android:orientation="vertical" >
   
           <TextView  android:layout_width="wrap_content" android:layout_height="wrap_content" android:singleLine="true" android:text="标题" android:id="@+id/tv_notification_title" android:textColor="@color/white" android:textSize="17sp" />
   
           <TextView  android:layout_width="wrap_content" android:layout_height="wrap_content" android:singleLine="true" android:text="艺术家" android:id="@+id/tv_notification_content" android:textColor="@color/gray_white" android:textSize="14sp" />
       </LinearLayout>
   
       <LinearLayout android:layout_width="0dp" android:layout_weight="1" android:gravity="center" android:orientation="horizontal" android:layout_height="40dp">
   
           <ImageView android:layout_width="30dp" android:layout_height="30dp" android:layout_marginRight="20dp" android:id="@+id/btn_notification_pre" android:background="@mipmap/icon_notification_pre"/>
   
           <ImageView android:layout_width="30dp" android:layout_height="30dp" android:id="@+id/btn_notification_next" android:background="@mipmap/icon_notification_next"/>
   
       </LinearLayout>
   
   </LinearLayout>

2. 通知栏的相关逻辑：

   1. 下一首
   2. 上一首
   3. 进入播放页

       /** * 发送自定义布局的通知 */
       private void sendNotification() {
           Notification.Builder builder = new Notification.Builder(AudioPlayerService.this);
           builder.setOngoing(true)
                   .setSmallIcon(R.mipmap.notification_music_playing)
                   .setTicker("正在播放:" + StringUtil.formatAudioName(audioList.get(currentPosition).getTitle()))
                   .setWhen(System.currentTimeMillis())
                   .setContent(getRemoteViews());
   
           startForeground(1, builder.build());
       }
   
       private RemoteViews getRemoteViews() {
           RemoteViews remoteViews = new RemoteViews(getPackageName(),
                   R.layout.layout_music_notification);
           remoteViews.setTextViewText(R.id.tv_notification_title, StringUtil.formatAudioName(audioList.get(currentPosition).getTitle()));
           remoteViews.setTextViewText(R.id.tv_notification_content, audioList.get(currentPosition).getArtist());
   
           remoteViews.setOnClickPendingIntent(R.id.btn_notification_pre, getPrePendingIntent());
           remoteViews.setOnClickPendingIntent(R.id.btn_notification_next, getNextPendingIntent());
           remoteViews.setOnClickPendingIntent(R.id.layout_notification, getContentPendingIntent());
   
           return remoteViews;
       }
   
       private PendingIntent getPrePendingIntent() {
           Intent intent = new Intent(AudioPlayerService.this, AudioPlayerService.class);
           intent.putExtra("viewAction", ACTION_NOTIFICATION_PRE);
           intent.putExtra("isFromNotification", true);
           PendingIntent pendingIntent = PendingIntent.getService(AudioPlayerService.this, 1, intent, PendingIntent.FLAG_UPDATE_CURRENT);
           return pendingIntent;
       }
   
       private PendingIntent getNextPendingIntent() {
           Intent intent = new Intent(AudioPlayerService.this, AudioPlayerService.class);
           intent.putExtra("viewAction", ACTION_NOTIFICATION_NEXT);
           intent.putExtra("isFromNotification", true);
           PendingIntent pendingIntent = PendingIntent.getService(AudioPlayerService.this, 2, intent, PendingIntent.FLAG_UPDATE_CURRENT);
           return pendingIntent;
       }
   
       private PendingIntent getContentPendingIntent() {
           Intent intent = new Intent(AudioPlayerService.this, AudioPlayerActivity.class);
           Bundle bundle = new Bundle();
           bundle.putInt("viewAction", ACTION_NOTIFICATION_LAYOUT);
           bundle.putBoolean("isFromNotification", true);
           intent.putExtras(bundle);
           PendingIntent pendingIntent = PendingIntent.getActivity(AudioPlayerService.this, 3, intent, PendingIntent.FLAG_UPDATE_CURRENT);
           return pendingIntent;
       }
   
   

   /*发送通知的方法应该在音乐准备完成和开始播放的时候调用*/
   
       private OnPreparedListener onPreparedListener = new OnPreparedListener() {
           @Override
           public void onPrepared(MediaPlayer mp) {
               mediaPlayer.start();
               notifyPrepared();
               sendNotification();
           }
       };
       public void start() {
           if (mediaPlayer != null) {
               mediaPlayer.start();
           }
           sendNotification();
       }
   
       //音乐准备暂停时移除通知
       public void pause() {
           if (mediaPlayer != null) {
               mediaPlayer.pause();
           }
           stopForeground(true);//移除通知
       }
   

歌词绘制

思路：自定义LyricView继承TextView，覆盖onSizeChanged(),onDraw()方法。

1. 绘制一行居中文本

   /** * 绘制水平居中的歌词文本 * * @param canvas 画布 * @param text 文本 * @param y 竖直方向的y坐标 * @param isLight 是否高亮 */
   private void drawCenterHorizontalText(Canvas canvas, String text, float y, boolean isLight) {
       paint.setColor(isLight ? LYRCI_HIGHLIGHT_COLOR : LYRIC_DEFAULT_COLOR);
       paint.setTextSize(isLight ?
               getResources().getDimension(R.dimen.lyric_highlight_textsize)
               : getResources().getDimension(R.dimen.lyric_default_textsize));
       float x = width / 2 - paint.measureText(text) / 2;
       canvas.drawText(text, x, y, paint);
   }
   

2. 绘制多行歌词

       /** * 绘制所有的歌词 * * @param canvas 画布 */
   private void drawLyricList(Canvas canvas) {
       Lyric lightLyric = lyricList.get(lightLyricIndex);
   
       //1.首先将高亮行的歌词绘制出来，作为一个参照物
       float lightLyricY = height / 2 + getTextHeight(lightLyric.getContent()) / 2;
       drawCenterHorizontalText(canvas, lightLyric.getContent(), lightLyricY, true);
       //2.遍历高亮行之前的歌词，并绘制出来
       for (int pre = 0; pre < lightLyricIndex; pre++) {
           Lyric lyric = lyricList.get(pre);
           float y = lightLyricY - (lightLyricIndex - pre) * LYRIC_ROW_HEIGHT;
           drawCenterHorizontalText(canvas, lyric.getContent(), y, false);
       }
       //3.遍历高亮行之后的歌词，并绘制出来
       for (int next = lightLyricIndex + 1; next < lyricList.size(); next++) {
           Lyric lyric = lyricList.get(next);
           float y = lightLyricY + (next - lightLyricIndex) * LYRIC_ROW_HEIGHT;
           drawCenterHorizontalText(canvas, lyric.getContent(), y, false);
       }
   
   }
   

   /** * 获取文本的高度 * * @param text 文本 * @return 文本的高度 */
   private float getTextHeight(String text) {
       Rect bounds = new Rect();
       paint.getTextBounds(text, 0, text.length(), bounds);
       return bounds.height();
   }

3. 滚动歌词

   /** * 滚动歌词 */
   public void roll(long currentPosition,long audioDuration){
       this.currentPosition = currentPosition;
       this.audioDuration = audioDuration;
       //1. 根据歌词播放的position，计算出高亮行的索引lightLyricIndex
       if(lyricList.size() != 0){
           //1.根据当前歌曲播放的位置去计算lightLyricIndex
           caculateLightLyricIndex();
       }
   
       //2. 拿到新的lightLyricIndex之后，更新view
       invalidate();
   }

   /** * 计算高亮歌词的索引值 * 只要当前音乐的position大于当前行的startPoint， * 并且小于下一行的startPoint，就是高亮行 */
   private void caculateLightLyricIndex() {
       for (int i = 0; i < lyricList.size(); i++) {
           long startPoint = lyricList.get(i).getStartPoint();
           if(i == lyricList.size() - 1){//最后一行
               if(currentPosition > startPoint){
                   lightLyricIndex = i;
               }
           }else{//不是最后一行
               Lyric next = lyricList.get(i + 1);
               if(currentPosition > startPoint && currentPosition < next.getStartPoint()){
                   lightLyricIndex = i;
               }
           }
   
       }
   }

4. 平滑滚动歌词

   /** * 绘制所有的歌词 * * @param canvas 画布 */
   private void drawLyricList(Canvas canvas) {
       Lyric lightLyric = lyricList.get(lightLyricIndex);
       //平滑移动歌词
       //1. 算出歌词的总的播放时间 即 下一行的startPoint - 当前的startPoint
       int totalDuration;
       if(lightLyricIndex==(lyricList.size()-1)){
           //如果最后一行是高亮行，则拿歌曲总时间减去当前的startPoint
           totalDuration = (int) (audioDuration - lightLyric.getStartPoint());
       }else {
           totalDuration = (int) (lyricList.get(lightLyricIndex+1).getStartPoint()-lightLyric.getStartPoint());
       }
       //2. 算出当前已经播放的秒数占总时间的百分比 currentAudioPosition - startPoint
       float offsetPosition = (int) (currentPosition - lightLyric.getStartPoint());
       float percent = offsetPosition/totalDuration;
       //3. 根据百分比算出应该移动的距离 percent * LYRIC_ROW_HEIGHT
       float dy = LYRIC_ROW_HEIGHT * percent;
       canvas.translate(0, -dy);
   
   
       //1.首先将高亮行的歌词绘制出来，作为一个参照物
       float lightLyricY = height / 2 + getTextHeight(lightLyric.getContent()) / 2;
       drawCenterHorizontalText(canvas, lightLyric.getContent(), lightLyricY, true);
       //2.遍历高亮行之前的歌词，并绘制出来
       for (int pre = 0; pre < lightLyricIndex; pre++) {
           Lyric lyric = lyricList.get(pre);
           float y = lightLyricY - (lightLyricIndex - pre) * LYRIC_ROW_HEIGHT;
           drawCenterHorizontalText(canvas, lyric.getContent(), y, false);
       }
       //3.遍历高亮行之后的歌词，并绘制出来
       for (int next = lightLyricIndex + 1; next < lyricList.size(); next++) {
           Lyric lyric = lyricList.get(next);
           float y = lightLyricY + (next - lightLyricIndex) * LYRIC_ROW_HEIGHT;
           drawCenterHorizontalText(canvas, lyric.getContent(), y, false);
       }
   
   }

5. 提供设置歌词的方法

       public void setLyricList(ArrayList<Lyric> lyricList){
           this.lyricList = lyricList;
           if(this.lyricList==null){
               hasNoLyric = true;
           }
       }

歌词解析

1. 读取每一行歌词文本
2. 解析每一行歌词

3. 对歌词集合进行排序

   /** * 歌词解析的工具类 */
   public class LyricParser {
       public static ArrayList<Lyric> parseLyricFromFile(File lyricFile){
           if(lyricFile==null || !lyricFile.exists())return null;
           ArrayList<Lyric> list = new ArrayList<Lyric>();
   
           try {
               //1.读取每一行歌词文本
               BufferedReader reader = new BufferedReader(new InputStreamReader
                       (new FileInputStream(lyricFile),"utf-8"));
               String line;
               while((line=reader.readLine())!=null){
                   //2.解析每一行歌词
                   //[00:04.05][00:24.05][01:24.05]北京北京 -> split("\\]")
                   //[00:04.05 [00:24.05 [01:24.05 北京北京
                   String[] arr = line.split("\\]");
                   for (int i = 0; i < arr.length-1; i++) {
                       Lyric lyric = new Lyric();
                       lyric.setContent(arr[arr.length-1]);//设置歌词内容
                       lyric.setStartPoint(formatStartPoint(arr[i]));
   
                       list.add(lyric);
                   }
               }
               //3.对歌词集合进行排序
               Collections.sort(list);//从小到大
           } catch (Exception e) {
               e.printStackTrace();
           }
   
           return list;
       }
   
       /** * 将[00:04.05转long类型的时间 * @param str * @return */
       private static long formatStartPoint(String str){
           str = str.substring(1);//00:04.05
           //1.先以冒号分割
           String[] arr1 = str.split("~i");//00 04.05
           String[] arr2 = arr1[1].split("\\.");//04 05
           int minute = Integer.parseInt(arr1[0]);//得到多少分钟
           int second = Integer.parseInt(arr2[0]);//得到多少秒
           int mills = Integer.parseInt(arr2[1]);//得到多少10毫秒
           return mills*10 + second*1000 + minute*60*1000;
       }
   
   }
   

   /**模拟歌词加载模块 * TODO：拿歌曲id去服务器请求对应的歌词文件 */
   public class LyricLoader {
   // private static final String LYRIC_DIR = Environment.getExternalStorageDirectory()+"/MIUI/music/lyric";
       private static final String LYRIC_DIR = Environment.getExternalStorageDirectory()+"/test/audio";
       public static File loadLyricFileByName(String audioName){
           File file = new File(LYRIC_DIR,StringUtil.formatAudioName(audioName)+".lrc");
           LogUtils.i(LYRIC_DIR);
           if(!file.exists()){
               file = new File(LYRIC_DIR,StringUtil.formatAudioName(audioName)+".txt");
           }
           return file;
       }
   }
   

好了，手机影音项目的整理就到这里。