Android视频播放器的手势控制实现

出处：
炎之铠邮箱：[e-mail]
博客地址：http://blog.csdn.net/totond
本文原创，转载请注明本出处！
本项目GitHub地址：https://github.com/totond/GestureTest

前言

　　现在很多全屏的视频播放器现在都有这样的功能：左边上下滑动调节亮度，右边上下滑动调节音量，左右滑动调节快进快退，双击控制暂停播放。实现这样的功能并不难，本文分享一下实现经验。

实现

　　本实现采用GestureDetector来处理输入的手势，它的介绍可以看我的GestureDetector全面分析，在这里就不详细讲它的用法了。对于GestureDetector的回调，我们还要把它封装才能区分出那些上下左右的手势，所以这里继承一个RelativeLayout来封装它们。下面只介绍了具体实现思路，想开具体细节的可以进入demo查看。

对GestureDetector的封装

　　主要是把onScroll()滑动回调分成3个部分：音量、手势和快进快退，所以最后开放给外部的接口是这样的：

    /**     * 用于提供给外部实现的视频手势处理接口     */    public interface VideoGestureListener {        //亮度手势，手指在Layout左半部上下滑动时候调用        public void onBrightnessGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY);        //音量手势，手指在Layout右半部上下滑动时候调用        public void onVolumeGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY);        //快进快退手势，手指在Layout左右滑动的时候调用        public void onFF_REWGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY);        //单击手势，确认是单击的时候调用        public void onSingleTapGesture(MotionEvent e);        //双击手势，确认是双击的时候调用        public void onDoubleTapGesture(MotionEvent e);        //按下手势，第一根手指按下时候调用        public void onDown(MotionEvent e);        //快进快退执行后的松开时候调用        public void onEndFF_REW(MotionEvent e);    }

　　为了给onScroll()分成3个部分，这里采用一个小小的状态模式，给它定义4个状态：NONE,VOLUME,BRIGHTNESS,FF_REW。只有NONE状态才能进入其他状态，其它状态一旦进入了不可切换，这样就保证了用户划着音量的时候不会突然就平移就改变了进度：

public class VideoPlayerOnGestureListener extends GestureDetector.SimpleOnGestureListener {//...        @Override        public boolean onDown(MotionEvent e) {            Log.d(TAG, "onDown: ");            //每次按下都重置为NONE            mScrollMode = NONE;            if (mVideoGestureListener != null) {                mVideoGestureListener.onDown(e);            }            return true;        }        @Override        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {            Log.d(TAG, "onScroll: e1:" + e1.getX() + "," + e1.getY());            Log.d(TAG, "onScroll: e2:" + e2.getX() + "," + e2.getY());            Log.d(TAG, "onScroll: X:" + distanceX + "  Y:" + distanceY);            switch (mScrollMode) {                case NONE:                    Log.d(TAG, "NONE: ");                    //offset是让快进快退不要那么敏感的值                    if (Math.abs(distanceX) - Math.abs(distanceY) > offsetX) {                        mScrollMode = FF_REW;                    } else {                        if (e1.getX() < getWidth() / 2) {                            mScrollMode = BRIGHTNESS;                        } else {                            mScrollMode = VOLUME;                        }                    }                    break;                case VOLUME:                    if (mVideoGestureListener != null) {                        mVideoGestureListener.onVolumeGesture(e1, e2, distanceX, distanceY);                    }                    Log.d(TAG, "VOLUME: ");                    break;                case BRIGHTNESS:                    if (mVideoGestureListener != null) {                        mVideoGestureListener.onBrightnessGesture(e1, e2, distanceX, distanceY);                    }                    Log.d(TAG, "BRIGHTNESS: ");                    break;                case FF_REW:                    if (mVideoGestureListener != null) {                        mVideoGestureListener.onFF_REWGesture(e1, e2, distanceX, distanceY);                    }                    hasFF_REW = true;                    Log.d(TAG, "FF_REW: ");                    break;            }            return true;        }//...}

　　然后在RelativeLayout里面使用这个VideoPlayerOnGestureListener，就让它们绑定了，只要在Activity里面使用这个RelativeLayout，就可以使用前面的VideoGestureListener接口的回调了。

public class VideoGestureRelativeLayout extends RelativeLayout {//...    public VideoGestureRelativeLayout(Context context) {        super(context);        init(context);    }    public VideoGestureRelativeLayout(Context context, AttributeSet attrs) {        super(context, attrs);        init(context);    }    private void init(Context context){        mOnGestureListener = new VideoPlayerOnGestureListener(this);        mGestureDetector = new GestureDetector(context,mOnGestureListener);        //取消长按，不然会影响滑动        mGestureDetector.setIsLongpressEnabled(false);        setOnTouchListener(new OnTouchListener() {            @Override            public boolean onTouch(View v, MotionEvent event) {                //实现快进快退松开时候的回调                if (event.getAction() == MotionEvent.ACTION_UP){                    if (hasFF_REW){                        if (mVideoGestureListener != null) {                            mVideoGestureListener.onEndFF_REW(event);                        }                        hasFF_REW = false;                    }                }                //监听触摸事件                return mGestureDetector.onTouchEvent(event);            }        });    }//...}

　　由于GestureDetector没有滑动之后松开的回调，这里在onTouch()方补一个回调。

具体控制实现

　　来到这里，接口已经做好了，用户的手势我们都收到相应的回调了，然后我们要做的是定义收到这些回调的时候的操作。

中间显示框

　　在这里我做了一个比较丑的中间显示框，里面包含着一个ImageView和一个ProgressBar，默认延时一秒后消失：

/** * Author: yanzhikai * Description: 中间用于显示状态的Layout * Email: [e-mail] */public class ShowChangeLayout extends RelativeLayout {    private static final String TAG = "gesturetest";    private ImageView iv_center;    private ProgressBar pb;    private HideRunnable mHideRunnable;    private int duration = 1000;    public ShowChangeLayout(Context context) {        super(context);        init(context);    }    public ShowChangeLayout(Context context, AttributeSet attrs) {        super(context, attrs);        init(context);    }    private void init(Context context){        LayoutInflater.from(context).inflate(R.layout.show_change_layout,this);        iv_center = (ImageView) findViewById(R.id.iv_center);        pb = (ProgressBar) findViewById(R.id.pb);        mHideRunnable = new HideRunnable();        ShowChangeLayout.this.setVisibility(GONE);    }    //显示    public void show(){        setVisibility(VISIBLE);        removeCallbacks(mHideRunnable);        postDelayed(mHideRunnable,duration);    }    //设置进度    public void setProgress(int progress){        pb.setProgress(progress);        Log.d(TAG, "setProgress: " +progress);    }    //设置持续时间    public void setDuration(int duration) {        this.duration = duration;    }    //设置显示图片    public void setImageResource(int resource){        iv_center.setImageResource(resource);    }    //隐藏自己的Runnable    private class HideRunnable implements Runnable{        @Override        public void run() {            ShowChangeLayout.this.setVisibility(GONE);        }    }}

亮度、音量、进度调节

　　首先是进行初始化：

public class MainActivity extends AppCompatActivity implements VideoGestureRelativeLayout.VideoGestureListener {    private final String TAG = "gesturetestm";    private VideoGestureRelativeLayout ly_VG;    private ShowChangeLayout scl;    private AudioManager mAudioManager;    private int maxVolume = 0;    private int oldVolume = 0;    private int newProgress = 0, oldProgress = 0;    private BrightnessHelper mBrightnessHelper;    private float brightness = 1;    private Window mWindow;    private WindowManager.LayoutParams mLayoutParams;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ly_VG = (VideoGestureRelativeLayout) findViewById(R.id.ly_VG);        ly_VG.setVideoGestureListener(this);        scl = (ShowChangeLayout) findViewById(R.id.scl);        //初始化获取音量属性        mAudioManager = (AudioManager)getSystemService(Service.AUDIO_SERVICE);        maxVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);        //初始化亮度调节        mBrightnessHelper = new BrightnessHelper(this);        //下面这是设置当前APP亮度的方法配置        mWindow = getWindow();        mLayoutParams = mWindow.getAttributes();        brightness = mLayoutParams.screenBrightness;    }    @Override    public void onDown(MotionEvent e) {        //每次按下的时候更新当前亮度和音量，还有进度        oldProgress = newProgress;        oldVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);        brightness = mLayoutParams.screenBrightness;        if (brightness == -1){            //一开始是默认亮度的时候，获取系统亮度，计算比例值            brightness = mBrightnessHelper.getBrightness() / 255f;        }    }//...}

　　每次onDown()都更新3个值的原因：onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)是每次Move事件位移大于1像素都会执行的（原因可看上一篇源码分析），distanceX和distanceY是两个MOVE之间的距离决定的，如果手指移动得比较慢，它们就会比较小，float转化成int很可能会被舍去小数点后的然后变成0，让用户不能慢慢通过滑动精准调控参数，所以要使用e2和e1的位移差来决定亮度等参数的变化大小，从而就要在onDown()获取旧数值来作为起始点了，详细逻辑请看代码：

//...    @Override    public void onVolumeGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {        int value = ly_VG.getHeight()/maxVolume ;        int newVolume = (int) ((e1.getY() - e2.getY())/value + oldVolume);        mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC,newVolume,AudioManager.FLAG_PLAY_SOUND);        //要强行转Float类型才能算出小数点，不然结果一直为0        int volumeProgress = (int) (newVolume/Float.valueOf(maxVolume) *100);        if (volumeProgress >= 50){            scl.setImageResource(R.drawable.volume_higher_w);        }else if (volumeProgress > 0){            scl.setImageResource(R.drawable.volume_lower_w);        }else {            scl.setImageResource(R.drawable.volume_off_w);        }        scl.setProgress(volumeProgress);        scl.show();    }    @Override    public void onBrightnessGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {        //下面这是设置当前APP亮度的方法        newBrightness += brightness;        if (newBrightness < 0){            newBrightness = 0;        }else if (newBrightness > 1){            newBrightness = 1;        }        mLayoutParams.screenBrightness = newBrightness;        mWindow.setAttributes(mLayoutParams);        scl.setProgress((int) (newBrightness * 100));        scl.setImageResource(R.drawable.brightness_w);        scl.show();    }    @Override    public void onEndFF_REW(MotionEvent e) {        makeToast("设置进度为" + newProgress);    }    @Override    public void onFF_REWGesture(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {        float offset = e2.getX() - e1.getX();        //根据移动的正负决定快进还是快退        if (offset > 0) {            scl.setImageResource(R.drawable.ff);            newProgress = (int) (oldProgress + offset/ly_VG.getWidth() * 100);            if (newProgress > 100){                newProgress = 100;            }        }else {            scl.setImageResource(R.drawable.fr);            newProgress = (int) (oldProgress + offset/ly_VG.getWidth() * 100);            if (newProgress < 0){                newProgress = 0;            }        }        scl.setProgress(newProgress);        scl.show();    }    @Override    public void onSingleTapGesture(MotionEvent e) {        makeToast("SingleTap");    }    @Override    public void onDoubleTapGesture(MotionEvent e) {        makeToast("DoubleTap");    }   private void makeToast(String str){        Toast.makeText(this,str,Toast.LENGTH_SHORT).show();    }//...

　　这里没有处理多点触控，所以实际效果是触控手指只看第一根，后面落下的手指动作都忽视。
　　最后贴出调节系统亮度的辅助类：

/** * Author: yanzhikai * Description: 用于辅助调节亮度的类 * Email: [e-mail] */public class BrightnessHelper {    private ContentResolver resolver;    private int maxBrightness = 255;    public BrightnessHelper(Context context){        resolver = context.getContentResolver();    }    /*     * 调整亮度范围     */    private int adjustBrightnessNumber(int brightness){        if (brightness < 0) {            brightness = 0;        } else if (brightness > 255) {            brightness = 255;        }        return brightness;    }    /*     * 关闭自动调节亮度     */    public void offAutoBrightness(){        try {            if(Settings.System.getInt(resolver, Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC)            {                Settings.System.putInt(resolver,                        Settings.System.SCREEN_BRIGHTNESS_MODE,                        Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);            }        } catch (Settings.SettingNotFoundException e) {            e.printStackTrace();        }    }    /*     * 获取系统亮度     */    public int getBrightness(){        return Settings.System.getInt(resolver, Settings.System.SCREEN_BRIGHTNESS, 255);    }    /*     * 设置系统亮度，如果有设置了自动调节，请先调用offAutoBrightness()方法关闭自动调节，否则会设置失败     */    public void setSystemBrightness(int newBrightness){        Settings.System.putInt(resolver, Settings.System.SCREEN_BRIGHTNESS                ,adjustBrightnessNumber(newBrightness));    }    public int getMaxBrightness() {        return maxBrightness;    }    /*     * 设置当前APP的亮度     */    public void setAppBrightness(float brightnessPercent, Activity activity){        Window window = activity.getWindow();        WindowManager.LayoutParams layoutParams = window.getAttributes();        layoutParams.screenBrightness = brightnessPercent;        window.setAttributes(layoutParams);    }}

　　上面调节亮度选择的是控制当前APP的亮度，不改变系统亮度。其实这些控制的实现是多种多样的，我这里只是给出一种封装GestureDetector的思路和实现方法，各个步骤都说得挺清楚了，具体的细节大家可以根据自己的需求改动。

后话

　　这篇博客是上一篇GestureDetector全面分析的后续，是GestureDetector的实践，原本是想合在一起的，结果发现太长了。经过GestureDetector的洗礼之后，感觉我对Android触摸事件输入的处理更加熟悉了，在这里分享出来我的经验，水平有限，如有错漏，敬请指正。
　　最后贴一下demo地址，喜欢的可以给个Star！
　　https://github.com/totond/GestureTest