【问题标题】:Detect Single Tap on webview检测 webview 上的单击
【发布时间】:2017-03-14 12:08:08
【问题描述】:

我在 webview 中使用运动事件,所以我不能直接在 touchlistener 上使用

我正在使用以下方式

package com.example.webviewdemo;

public class OnSwipeTouchListener implements OnTouchListener {

private final GestureDetector gestureDetector;
private long touchDownMs;
private Handler handler;
private int numberOfTaps;
private long lastTapTimeMs;


public OnSwipeTouchListener(Context context) {
    gestureDetector = new GestureDetector(context, new GestureListener());
}

public void onSwipeLeft() {
}

public void onSwipeRight() {
}
public void newTouch(){

}
public boolean onTouch(View v, MotionEvent event) {
      gestureDetector.onTouchEvent(event);
      handler= new Handler();
     if(event.getAction()== MotionEvent.ACTION_MOVE)
     {
         return true;
     }



      if(event.getAction()== MotionEvent.ACTION_DOWN){

          touchDownMs = System.currentTimeMillis();
          return v.onTouchEvent(event);
     }
     else if(event.getAction()== MotionEvent.ACTION_UP){

          handler.removeCallbacksAndMessages(null);

          if ((System.currentTimeMillis() - touchDownMs) > ViewConfiguration.getTapTimeout()) {
              //it was not a tap

              numberOfTaps = 0;
              lastTapTimeMs = 0;

          }

          if (numberOfTaps > 0 
                  && (System.currentTimeMillis() - lastTapTimeMs) < ViewConfiguration.getDoubleTapTimeout()) {
              numberOfTaps += 1;
          } else {
              numberOfTaps = 1;
          }

          lastTapTimeMs = System.currentTimeMillis();

          if (numberOfTaps == 3) {
 //                  Toast.makeText(getApplicationContext(), "triple", Toast.LENGTH_SHORT).show();
              //handle triple tap
          } else if (numberOfTaps == 2) {
              handler.postDelayed(new Runnable() {
                  @Override
                  public void run() {
                      //handle double tap
                      newTouch();
//                          Toast.makeText(getApplicationContext(), "double", Toast.LENGTH_SHORT).show();
                  }
              }, ViewConfiguration.getDoubleTapTimeout());
          }
          return v.onTouchEvent(event);
     }
          else{
              return v.onTouchEvent(event);
             }


 }

private final class GestureListener extends SimpleOnGestureListener {

    private static final int SWIPE_DISTANCE_THRESHOLD = 100;
    private static final int SWIPE_VELOCITY_THRESHOLD = 100;

    @Override
    public boolean onDown(MotionEvent e) {
        return true;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        float distanceX = e2.getX() - e1.getX();
        float distanceY = e2.getY() - e1.getY();
        if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
            if (distanceX > 0)
                onSwipeRight();
            else
                onSwipeLeft();
            return true;
        }
        return false;
    }

}


}

在我的 webview 上实现

    webView.setOnTouchListener(new OnSwipeTouchListener(this) {
                        @Override
                        public void onSwipeLeft() {
                            // Whatever


                        }
                        @Override
                        public void onSwipeRight() {
                            // TODO Auto-generated method stub



                        }
                        @Override
                        public void newTouch() {
                            // TODO Auto-generated method stub

                        }

                    });

我可以从中获得双击和三次点击,但我只需要一次完整的点击,不仅是 ACTION_UP 或 ACTION_DOWN,而且两者都在毫秒间隙内。 如果在我的代码中我写了 numberOfTaps ==1 那么它正在检测 Action_Down 没有完成点击。我需要完成 1 次点击检测。 提前致谢

我已经看到 ThisThis 但没有工作

【问题讨论】:

    标签: android webview gesture-recognition


    【解决方案1】:
    package com.example.webviewdemo;
    
    public class OnSwipeTouchListener implements OnTouchListener {
    
    private final GestureDetector gestureDetector;
    private static final int MAX_CLICK_DURATION = 1000;
    private static final int MAX_CLICK_DISTANCE = 15;
    static Context mcontext;
    private long pressStartTime;
    private float pressedX;
    private float pressedY;
    private boolean stayedWithinClickDistance;
    
    public OnSwipeTouchListener(Context context) {
        gestureDetector = new GestureDetector(context, new GestureListener());
        this.mcontext=context;
    }
    
    public void onSwipeLeft() {
    }
    
    public void onSwipeRight() {
    }
    public void newTouch(){
    
    }
    public boolean onTouch(View v, MotionEvent event) {
          gestureDetector.onTouchEvent(event);
    
         if(event.getAction()== MotionEvent.ACTION_MOVE)
         {
              if (stayedWithinClickDistance && distance(pressedX, pressedY, event.getX(), event.getY()) > MAX_CLICK_DISTANCE) {
                  stayedWithinClickDistance = false;
              }
             return true;
         }
    
         else if (event.getAction()== MotionEvent.ACTION_DOWN) {
             pressStartTime = System.currentTimeMillis();                
             pressedX = event.getX();
             pressedY = event.getY();
             stayedWithinClickDistance = true;
    
             return v.onTouchEvent(event);
         }
         else if(event.getAction()== MotionEvent.ACTION_UP) {
    
             long pressDuration = System.currentTimeMillis() - pressStartTime;
             if (pressDuration < MAX_CLICK_DURATION && stayedWithinClickDistance) {
                newTouch();
             }
    
             return v.onTouchEvent(event);
         }
         else{
             return v.onTouchEvent(event);
         }
    
    }
    private static float distance(float x1, float y1, float x2, float y2) {
        float dx = x1 - x2;
        float dy = y1 - y2;
        float distanceInPx = (float) Math.sqrt(dx * dx + dy * dy);
        return pxToDp(distanceInPx);
    }
    
    private static float pxToDp(float px) {
        return px / mcontext.getResources().getDisplayMetrics().density;
    }
    
    
    private final class GestureListener extends SimpleOnGestureListener {
    
        private static final int SWIPE_DISTANCE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;
    
        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }
    
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            float distanceX = e2.getX() - e1.getX();
            float distanceY = e2.getY() - e1.getY();
            if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                if (distanceX > 0)
                    onSwipeRight();
                else
                    onSwipeLeft();
                return true;
            }
            return false;
        }
    
    }
    
    
    }
    

    用这个How to distinguish between move and click in onTouchEvent()?解决了它

    【讨论】:

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