在Android“视图"上进行DoubleTap检测成分 [英] DoubleTap detection on Android "View" component

问题描述

我需要在这里实现如下 1)在PNG图像上叠加一个透明的点"；用户点击的位置. 2)当用户长时间按住触摸时，叠加一个透明的大圆圈". 3)在Doble中，单击清除屏幕"

What I need to achieve here is as following 1) superimpose a transperent "dot" on the PNG image ; where user has clicked. 2) superimpose a transperent "Big circle", when user is holding touch for long. 3) upon Doble click "Clear the screen"

主要是我将"onTouchEvent"用于单击事件检测...，将"geastureDetector"用于doubleTap检测...但未获得期望的结果.

Primarily I am using "onTouchEvent" for click-event detection... and "geastureDetector" for doubleTap detection... but not getting the desired result.

这些是我正在尝试的2种实现

These are the 2 implementations I am trying out

第一种方法效果很好...但是生成的点击事件存在一定的偏差...我的意思是说，捕获的点击事件在Y方向上始终偏移约50个像素....我无法弄清楚为什么会发生这种情况.

This first approach works fine ... But the click event generated is with some deviation... I mean to say the click event captured is always Offset by around 50 pixels in Y direction.... I am not able to figure out why this should happen..

class Tileview extends Activity implements GestureDetector.OnGestureListener,GestureDetector.OnDoubleTapListener {

onCreate(){
  //add the View Thing here.
}

@Override
public void onLongPress(MotionEvent e) {
   // "longPress Detected"
}

@Override
public boolean onDoubleTap(MotionEvent e) {
  // "longPress Detected"
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    final int action = event.getActionMasked();
    switch(action){
    case MotionEvent.ACTION_DOWN:           
        mClickX = event.getX();
        mClickY = event.getY();     

    }
    myTileView.invalidate();
    return mGestureDetector.onTouchEvent(event);
}



private class MyTileView extends View{

protected void onDraw(Canvas canvas){
   // Canvas & Paint stuff - for translucent cicle 
   c.drawCircle(mClickX, mClickY, 75.0f, p);
   }
}

另一种方法是在适当的位置适当地叠加图像；但是，当我在视图"而不是Activity中添加DoubleTap实现时，doubleTap/geastureListeners将永远不会触发.. 在那种情况下，我所做的唯一更改是获取了onTouchEvent()-并在"view"类中进行了相应的实现....

The other approach is able to superimpose the image propely at proper location; but when I add the DoubleTap implementation in the "View" instead of Activity .. the doubleTap / geastureListeners would never fire .... Only change I did in that case was to get the onTouchEvent() - and corrsponding implementation in "view" class....

class TileActivity extends Activity {

   OnCreate()
          { 
          // Bla Bla Bla       
          }

    private class TileView extends View implements OnDoubleTapListener, OnGestureListener{
            @override
            onTouchEvent(){
                    // get co-ordinates here from MotionEvent
            }

    @Override
    public boolean onDoubleTap(MotionEvent e) {

                  // THIS WON'T EVEN GET FIRED
                  // In this case the doubleTap detection is not working

        clearEntireScreen = true;
        return false;
    }
    }
}

推荐答案

现在已解决...！ 解决该问题的最佳方法似乎是创建gestureDetector类并实现"SimpleOnGestureListener"..

It is RESOLVED now...!! Seems the best way to tackle the issue was to create gestureDetector class and implement "SimpleOnGestureListener"..

我不得不稍微调整一下实现...但是最基本的代码与这篇博文中的解释非常相似... 在网格布局上翻转手势检测

I had to tweak the implementation a little bit... but the skeleton code is much more similar to what is explained here in this post... Fling gesture detection on grid layout

我必须重写LongPress/onDoubleTap/onSigleTapUp/onSingletap确认的方法才能获得所需的结果...

I had to override LongPress / onDoubleTap / onSigleTapUp / onSingletapconfirmed methods to achieve the desired results...

感谢您的帮助... !!

Thanks for the help... !!

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