出处：
炎之铠邮箱：yanzhikai_yjk@qq.com
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: yanzhikai_yjk@qq.com
*/
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: yanzhikai_yjk@qq.com
*/
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
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