android开发之GestureDetector手势识别（调节音量、亮度、快进和后退）

大家好，又见面了，我是全栈君。

这里写图片描写叙述

写UI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="match_parent" android:fitsSystemWindows="true" android:orientation="vertical" >

    <include  android:id="@+id/root_layout" android:layout_width="match_parent" android:layout_height="200dp" layout="@layout/video_layout" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" >

    <com.zanelove.gesturedetectordemo.views.MyVideoView  android:id="@+id/tv_pro_play" android:layout_width="match_parent" android:layout_height="match_parent" />

    <LinearLayout  android:id="@+id/ll_player_controller" android:layout_width="match_parent" android:layout_height="50dp" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" android:background="#c0000000" android:gravity="center" android:orientation="horizontal" android:visibility="gone">

        <ImageView  android:id="@+id/iv_play_pause" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="15dp" android:src="@drawable/btn_pause" />

        <TextView  android:id="@+id/tv_playing_time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="15dp" android:text="00:00" android:textColor="@android:color/darker_gray" android:textSize="15sp" />

        <SeekBar  android:id="@+id/sb_video_progress" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginLeft="5dp" android:layout_weight="2" />

        <TextView  android:id="@+id/tv_total_time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="5dp" android:text="00:00" android:textColor="@android:color/darker_gray" android:textSize="15sp" />

        <ImageView  android:id="@+id/iv_full_screen" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="15dp" android:padding="15dp" android:src="@drawable/btn_full_screen" />
    </LinearLayout>

    <RelativeLayout  android:id="@+id/gesture_volume_layout" android:layout_width="120dip" android:layout_height="100dip" android:layout_centerInParent="true" android:background="@drawable/souhu_player_gesture_bg" android:gravity="center" android:visibility="gone" >

        <ImageView  android:id="@+id/gesture_iv_player_volume" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:src="@drawable/souhu_player_volume" />

        <TextView  android:id="@+id/geture_tv_volume_percentage" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/gesture_iv_player_volume" android:layout_centerHorizontal="true" android:gravity="right" android:text="80%" android:textColor="#ffececec" />
    </RelativeLayout>

    <RelativeLayout  android:id="@+id/gesture_bright_layout" android:layout_width="120dip" android:layout_height="100dip" android:layout_centerInParent="true" android:background="@drawable/souhu_player_gesture_bg" android:gravity="center" android:visibility="gone" >

        <ImageView  android:id="@+id/gesture_iv_player_bright" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:src="@drawable/souhu_player_bright" />

        <TextView  android:id="@+id/geture_tv_bright_percentage" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/gesture_iv_player_bright" android:layout_centerHorizontal="true" android:gravity="right" android:text="80%" android:textColor="#ffececec" />
    </RelativeLayout>

    <RelativeLayout  android:id="@+id/gesture_progress_layout" android:layout_width="120dip" android:layout_height="100dip" android:layout_centerInParent="true" android:background="@drawable/souhu_player_gesture_bg" android:gravity="center" android:visibility="gone">

        <ImageView  android:id="@+id/gesture_iv_progress" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:src="@drawable/souhu_player_backward" />

        <TextView  android:id="@+id/geture_tv_progress_time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/gesture_iv_progress" android:layout_centerHorizontal="true" android:gravity="right" android:text="00:35/24:89" android:textColor="#ffececec" />
    </RelativeLayout>

</RelativeLayout>

以上将UI布局给大伙粘贴上来了。大家依照各自的需求改吧改吧…就可以

那么。就下来我将首先给大家分析分析怎样通过手势识别来调节音量、亮度、快键和后退需求！

一提到手势识别。大伙第一反应绝对是Google提供给我们的GestureDetector类，没错今天我们就使用使用这个类来给大家完毕以上的需求！

第一：将主逻辑代码类继承FragmentActivity类并实现OnGestureListener监听和OnTouchListener监听，同一时候在onCreate方法中创建GestureDetector对象，这时须要传递两个对象，这也是为啥我要继承和实现了！

GestureDetector gestureDetector = new GestureDetector(this, this);

第二：获取UI布局中定义的控件

这些你全然能够使用xUtils第三方工具的注解来完毕下面操作：

@ViewInject(R.id.gesture_bright_layout)
RelativeLayout gesture_bright_layout;

ViewUtils.inject(this);

也能够通过findViewById方法：

// 视频播放控件
tv_pro_play = (MyVideoView) findViewById(R.id.tv_pro_play);

/* iv_full_screen = (ImageView) findViewById(R.id.iv_full_screen); iv_play_pause = (ImageView) findViewById(R.id.iv_play_pause); ll_player_controller = (LinearLayout) findViewById(R.id.ll_player_controller); iv_play_pause = (ImageView) findViewById(R.id.iv_play_pause); sb_video_progress = (SeekBar) findViewById(R.id.sb_video_progress); iv_full_screen = (ImageView) findViewById(R.id.iv_full_screen); tv_playing_time = (TextView) findViewById(R.id.tv_playing_time); tv_total_time = (TextView) findViewById(R.id.tv_total_time);*/

// ****************音量/进度/亮度*********************

root_layout = (RelativeLayout) findViewById(R.id.root_layout);
gesture_volume_layout = (RelativeLayout) findViewById(R.id.gesture_volume_layout);
gesture_bright_layout = (RelativeLayout) findViewById(R.id.gesture_bright_layout);
gesture_progress_layout = (RelativeLayout) findViewById(R.id.gesture_progress_layout);
geture_tv_progress_time = (TextView) findViewById(R.id.geture_tv_progress_time);
geture_tv_volume_percentage = (TextView) findViewById(R.id.geture_tv_volume_percentage);
geture_tv_bright_percentage = (TextView) findViewById(R.id.geture_tv_bright_percentage);
gesture_iv_progress = (ImageView) findViewById(R.id.gesture_iv_progress);
gesture_iv_player_volume = (ImageView) findViewById(R.id.gesture_iv_player_volume);
gesture_iv_player_bright = (ImageView) findViewById(R.id.gesture_iv_player_bright);
gestureDetector = new GestureDetector(this, this); //须要实现OnGestureListener监听
root_layout.setLongClickable(true);
gestureDetector.setIsLongpressEnabled(true);
root_layout.setOnTouchListener(this);//须要实现OnTouchListener监听
audiomanager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
maxVolume = audiomanager.getStreamMaxVolume(AudioManager.STREAM_MUSIC); // 获取系统最大音量
currentVolume = audiomanager.getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值

第三：获取视频播放窗体的尺寸，推断触发的视频播放窗体位置来识别不同的操作和需求：

/** 获取视频播放窗体的尺寸 */
ViewTreeObserver viewObserver = root_layout.getViewTreeObserver();
viewObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        root_layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
        playerWidth = root_layout.getWidth();
        playerHeight = root_layout.getHeight();
    }
});

第四：当你实现OnGestureListener监听和OnTouchListener监听时是须要您实现其方法的。各自是：

当你实现了OnTouchListener监听须要覆写其方法：
@Override
public boolean onTouch(View v, MotionEvent event) {
    return false;
}

当你实现了OnGestureListener监听须要覆写一下方法：
// 用户轻触触摸屏，由1个MotionEvent ACTION_DOWN触发 
@Override
public boolean onDown(MotionEvent e) {
    return false;
}

// 用户按下触摸屏，并拖动，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE触发
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
    return false;
}

// 用户（轻触触摸屏后）松开，由1个MotionEvent ACTION_UP触发
@Override
public boolean onSingleTapUp(MotionEvent e) {
    return false;
}

// 用户按下触摸屏、高速移动后松开，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE, 1个ACTION_UP触发
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
    return false;
}

// 用户长按触摸屏，由多个MotionEvent ACTION_DOWN触发
@Override
public void onLongPress(MotionEvent e) {}

// 用户轻触触摸屏，尚未松开或拖动，由1个MotionEvent ACTION_DOWN触发, 注意和onDown()的差别，强调的是没有松开或者拖动的状态
@Override
public void onShowPress(MotionEvent e) {}

能够看到OnTouchListener仅仅能监听到三种触摸事件，即按下。移动，松开，假设想要监听到双击、滑动、长按等复杂的手势操作，这个时候就必须得用到OnGestureListener了。

因此在onTouch()方法中，我们要进行例如以下的处理：

@Override
public boolean onTouch(View v, MotionEvent event) {
    // 手势里除了singleTapUp，没有其它检測up的方法
    if (event.getAction() == MotionEvent.ACTION_UP) {
        GESTURE_FLAG = 0;// 手指离开屏幕后，重置调节音量或进度的标志
        gesture_volume_layout.setVisibility(View.GONE);
        gesture_bright_layout.setVisibility(View.GONE);
        gesture_progress_layout.setVisibility(View.GONE);
    }
    return gestureDetector.onTouchEvent(event);//假设想要监听到双击、滑动、长按等复杂的手势操作，这个时候就必须得用到OnGestureListener了
}

同一时候点击屏幕时触发的onDown()方法中：

@Override
public boolean onDown(MotionEvent e) {
    firstScroll = true;// 设定是触摸屏幕后第一次scroll的标志
    return false;
}

通过在onTouch()方法中调用gestureDetector.onTouchEvent(event)方法时，它会去调用onScroll()方法，这样在该方法中通过手势识别来完毕调节音量、亮度、快键和后退操作：

@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
    float mOldX = e1.getX(), mOldY = e1.getY();
    int y = (int) e2.getRawY();
    if (firstScroll) {// 以触摸屏幕后第一次滑动为标准，避免在屏幕上操作切换混乱
        // 横向的距离变化大则调整进度，纵向的变化大则调整音量
        if (Math.abs(distanceX) >= Math.abs(distanceY)) {
            gesture_progress_layout.setVisibility(View.VISIBLE);
            gesture_volume_layout.setVisibility(View.GONE);
            gesture_bright_layout.setVisibility(View.GONE);
            GESTURE_FLAG = GESTURE_MODIFY_PROGRESS;
        } else {
            if (mOldX > playerWidth * 3.0 / 5) {// 音量
                gesture_volume_layout.setVisibility(View.VISIBLE);
                gesture_bright_layout.setVisibility(View.GONE);
                gesture_progress_layout.setVisibility(View.GONE);
                GESTURE_FLAG = GESTURE_MODIFY_VOLUME;
            } else if (mOldX < playerWidth * 2.0 / 5) {// 亮度
                gesture_bright_layout.setVisibility(View.VISIBLE);
                gesture_volume_layout.setVisibility(View.GONE);
                gesture_progress_layout.setVisibility(View.GONE);
                GESTURE_FLAG = GESTURE_MODIFY_BRIGHT;
            }
        }
    }

    // 假设每次触摸屏幕后第一次scroll是调节进度。那之后的scroll事件都处理音量进度，直到离开屏幕运行下一次操作
    if (GESTURE_FLAG == GESTURE_MODIFY_PROGRESS) {
        // distanceX=lastScrollPositionX-currentScrollPositionX，因此为正时是快进
        if (Math.abs(distanceX) > Math.abs(distanceY)) {// 横向移动大于纵向移动
            if (distanceX >= DensityUtil.dip2px(this, STEP_PROGRESS)) {// 快退，用步长控制改变速度。可微调
                gesture_iv_progress.setImageResource(R.drawable.souhu_player_backward);
                if (playingTime > 3) {// 避免为负
                    playingTime -= 3;// scroll方法运行一次快退3秒
                } else {
                    playingTime = 0;
                }
            } else if (distanceX <= -DensityUtil.dip2px(this, STEP_PROGRESS)) {// 快进
                gesture_iv_progress.setImageResource(R.drawable.souhu_player_forward);
                if (playingTime < videoTotalTime - 16) {// 避免超过总时长
                    playingTime += 3;// scroll运行一次快进3秒
                } else {
                    playingTime = videoTotalTime - 10;
                }
            }
            if (playingTime < 0) {
                playingTime = 0;
            }
            tv_pro_play.seekTo(playingTime);
            geture_tv_progress_time.setText(DateTools.getTimeStr(playingTime) + "/" + DateTools.getTimeStr(videoTotalTime));
        }
    }

    // 假设每次触摸屏幕后第一次scroll是调节音量，那之后的scroll事件都处理音量调节。直到离开屏幕运行下一次操作
    else if (GESTURE_FLAG == GESTURE_MODIFY_VOLUME) {
        currentVolume = audiomanager.getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值
        if (Math.abs(distanceY) > Math.abs(distanceX)) {// 纵向移动大于横向移动
            if (distanceY >= DensityUtil.dip2px(this, STEP_VOLUME)) {// 音量调大,注意横屏时的坐标体系,虽然左上角是原点，但横向向上滑动时distanceY为正
                if (currentVolume < maxVolume) {// 为避免调节过快，distanceY应大于一个设定值
                    currentVolume++;
                }
                gesture_iv_player_volume.setImageResource(R.drawable.souhu_player_volume);
            } else if (distanceY <= -DensityUtil.dip2px(this, STEP_VOLUME)) {// 音量调小
                if (currentVolume > 0) {
                    currentVolume--;
                    if (currentVolume == 0) {// 静音，设定静音独有的图片
                        gesture_iv_player_volume.setImageResource(R.drawable.souhu_player_silence);
                    }
                }
            }
            int percentage = (currentVolume * 100) / maxVolume;
            geture_tv_volume_percentage.setText(percentage + "%");
            audiomanager.setStreamVolume(AudioManager.STREAM_MUSIC,currentVolume, 0);
        }
    }

    // 假设每次触摸屏幕后第一次scroll是调节亮度，那之后的scroll事件都处理亮度调节。直到离开屏幕运行下一次操作
    else if (GESTURE_FLAG == GESTURE_MODIFY_BRIGHT) {
        gesture_iv_player_bright.setImageResource(R.drawable.souhu_player_bright);
        if (mBrightness < 0) {
            mBrightness = getWindow().getAttributes().screenBrightness;
            if (mBrightness <= 0.00f)
                mBrightness = 0.50f;
            if (mBrightness < 0.01f)
                mBrightness = 0.01f;
        }
        WindowManager.LayoutParams lpa = getWindow().getAttributes();
        lpa.screenBrightness = mBrightness + (mOldY - y) / playerHeight;
        if (lpa.screenBrightness > 1.0f)
            lpa.screenBrightness = 1.0f;
        else if (lpa.screenBrightness < 0.01f)
            lpa.screenBrightness = 0.01f;
        getWindow().setAttributes(lpa);
        geture_tv_bright_percentage.setText((int) (lpa.screenBrightness * 100) + "%");
    }

    firstScroll = false;// 第一次scroll运行完毕，改动标志
    return false;
}