Android-视频播放实例之手势控制音乐、亮度

﹏ヽ暗。殇╰゛Y 2022-08-01 00:12 254阅读 0赞

手势控制视频播放是现在视频播放软件的主要控制手段之一，本文主要讲解下如何实现在android平台下如何实现通过手势控制。

## 一、GestureDetector ##

通常我们要实现检测用户对控件的检测都需要用到View.OnTouchListener这个方法，过重写他onTouch(View v, MotionEvent event)方法，但是这个方法所实现的手势比较简单，当我们需要一些比较复杂的手势的时候它就不能满足我们的需求了，但是google公司考虑的比较充分，Android sdk给我们提供GestureDetector（Gesture：手势Detector：识别）类，通过这个类我们可以识别很多的手势，主要是通过他的onTouchEvent(event)方法完成了不同手势的识别。虽然他能识别手势，但是不同的手势要怎么处理，应该是提供给程序员实现的。
    GestureDetector里面实现了一些常用的手势接口，如：
     1.   onDown(MotionEvent e)：down事件；
     2.   onSingleTapUp(MotionEvent e)：一次点击up事件；在touch down后又没有滑动（onScroll），又没有长按（onLongPress），然后Touchup时触发。 点击一下非常快的（不滑动）Touchup：onDown->onSingleTapUp->onSingleTapConfirmed 点击一下稍微慢点的（不滑动）Touchup：onDown->onShowPress->onSingleTapUp->onSingleTapConfirmed
     3.   onShowPress(MotionEvent e)：down事件发生而move或则up还没发生前触发该事件；Touch了还没有滑动时触发（与onDown，onLongPress）比较onDown只要Touch down一定立刻触发。而Touchdown后过一会没有滑动先触发onShowPress再是onLongPress。所以Touchdown后一直不滑动按照onDown->onShowPress->onLongPress这个顺序触发。 
     4.   onLongPress(MotionEvent e)：长按事件；Touch了不移动一直Touch down时触发 
     5.   onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)：滑动手势事件；Touch了滑动一点距离后，在ACTION_UP时才会触发    参数：e1 第1个ACTION_DOWN MotionEvent 并且只有一个；e2 最后一个ACTION_MOVE MotionEvent ；velocityX X轴上的移动速度，像素/秒 ；velocityY Y轴上的移动速度，像素/秒.触发条件：X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒
     6.   onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)：在屏幕上拖动事件。无论是用手拖动view，或者是以抛的动作滚动，都会多次触发,这个方法在ACTION_MOVE动作发生时就会触发

## 二、音量和亮度控制具体代码实现： ##

public class PlayActivity extends Activity {
    private static final String TAG = "MediaPlayerDemo";
    private int mVideoWidth;
    private int mVideoHeight;
    private VideoView mVideoView;
    private String path;;
    private View mVolumeBrightnessLayout;
    private ImageView mOperationBg;
    private ImageView mOperationPercent;
    private AudioManager mAudioManager;
    /** 最大声音 */
    private int mMaxVolume;
    /** 当前声音 */
    private int mVolume = -1;
    /** 当前亮度 */
    private float mBrightness = -1f;
    /** 当前缩放模式 */
    private int mLayout = VideoView.VIDEO_LAYOUT_ZOOM;
    private GestureDetector mGestureDetector;
     private MediaController mMediaController;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO 自动生成的方法存根
        super.onCreate(savedInstanceState);
        if (!LibsChecker.checkVitamioLibs(this))
            return;
        //全屏
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams. FLAG_FULLSCREEN ,
                  WindowManager.LayoutParams. FLAG_FULLSCREEN);
        setContentView(R.layout.activity_play);
        path=Environment.getExternalStorageDirectory()+ "/317.mp4";
         mVolumeBrightnessLayout = findViewById(R.id.operation_volume_brightness);
         mOperationBg = (ImageView) findViewById(R.id.operation_bg);
         mOperationPercent = (ImageView) findViewById(R.id.operation_percent);
         mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
         mMaxVolume = mAudioManager
                 .getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        mVideoView=(VideoView) findViewById(R.id.play_view);
        mVideoView.setVideoPath(path);
        mMediaController = new MediaController(this);
        mVideoView.setMediaController(mMediaController);
        mVideoView.requestFocus();
        mVideoView.start();
    
        mGestureDetector = new GestureDetector(this, new MyGestureListener());
    }
    protected void onResume() {
         /**
          * 设置为横屏
          */
         if(getRequestedOrientation()!=ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE){
          setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
         }
         super.onResume();
        }
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (mGestureDetector.onTouchEvent(event))
             return true;
    
         // 处理手势结束
         switch (event.getAction() & MotionEvent.ACTION_MASK) {
         case MotionEvent.ACTION_UP:
             endGesture();
             break;
         }
    
         return super.onTouchEvent(event);
     }
    
     /** 手势结束 */
     private void endGesture() {
         mVolume = -1;
         mBrightness = -1f;
    
         // 隐藏
         mDismissHandler.removeMessages(0);
         mDismissHandler.sendEmptyMessageDelayed(0, 500);
     }
    
     private class MyGestureListener extends SimpleOnGestureListener {
    
         /** 双击 */
         @Override
         public boolean onDoubleTap(MotionEvent e) {
             if (mLayout == VideoView.VIDEO_LAYOUT_ZOOM)
                 mLayout = VideoView.VIDEO_LAYOUT_ORIGIN;
             else
                 mLayout++;
             if (mVideoView != null)
                 mVideoView.setVideoLayout(mLayout, 0);
             return true;
         }
    
         /** 滑动 */
         @Override
         public boolean onScroll(MotionEvent e1, MotionEvent e2,
                 float distanceX, float distanceY) {
             float mOldX = e1.getX(), mOldY = e1.getY();
             int y = (int) e2.getRawY();
             Display disp = getWindowManager().getDefaultDisplay();
             int windowWidth = disp.getWidth();
             int windowHeight = disp.getHeight();
    
             if (mOldX > windowWidth * 4.0 / 5)// 右边滑动
                 onVolumeSlide((mOldY - y) / windowHeight);
             else if (mOldX < windowWidth / 5.0)// 左边滑动
                 onBrightnessSlide((mOldY - y) / windowHeight);
    
             return super.onScroll(e1, e2, distanceX, distanceY);
         }
     }
    
     /** 定时隐藏 */
     private Handler mDismissHandler = new Handler() {
         @Override
         public void handleMessage(Message msg) {
             mVolumeBrightnessLayout.setVisibility(View.GONE);
         }
     };
    
     /**
      * 滑动改变声音大小
      * 
      * @param percent
      */
     private void onVolumeSlide(float percent) {
         if (mVolume == -1) {
             mVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
             if (mVolume < 0)
                 mVolume = 0;
    
             // 显示
             mOperationBg.setImageResource(R.drawable.video_volumn_bg);
             mVolumeBrightnessLayout.setVisibility(View.VISIBLE);
         }
    
         int index = (int) (percent * mMaxVolume) + mVolume;
         if (index > mMaxVolume)
             index = mMaxVolume;
         else if (index < 0)
             index = 0;
    
         // 变更声音
         mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, index, 0);
    
         // 变更进度条
         ViewGroup.LayoutParams lp = mOperationPercent.getLayoutParams();
         lp.width = findViewById(R.id.operation_full).getLayoutParams().width
                 * index / mMaxVolume;
         mOperationPercent.setLayoutParams(lp);
     }
    
     /**
      * 滑动改变亮度
      * 
      * @param percent
      */
     private void onBrightnessSlide(float percent) {
         if (mBrightness < 0) {
             mBrightness = getWindow().getAttributes().screenBrightness;
             if (mBrightness <= 0.00f)
                 mBrightness = 0.50f;
             if (mBrightness < 0.01f)
                 mBrightness = 0.01f;
    
             // 显示
             mOperationBg.setImageResource(R.drawable.video_brightness_bg);
             mVolumeBrightnessLayout.setVisibility(View.VISIBLE);
         }
         WindowManager.LayoutParams lpa = getWindow().getAttributes();
         lpa.screenBrightness = mBrightness + percent;
         if (lpa.screenBrightness > 1.0f)
             lpa.screenBrightness = 1.0f;
         else if (lpa.screenBrightness < 0.01f)
             lpa.screenBrightness = 0.01f;
         getWindow().setAttributes(lpa);
    
         ViewGroup.LayoutParams lp = mOperationPercent.getLayoutParams();
         lp.width = (int) (findViewById(R.id.operation_full).getLayoutParams().width * lpa.screenBrightness);
         mOperationPercent.setLayoutParams(lp);
     }
    
     @Override
     public void onConfigurationChanged(Configuration newConfig) {
         if (mVideoView != null)
             mVideoView.setVideoLayout(mLayout, 0);
         super.onConfigurationChanged(newConfig);
             }
    }

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