android - 检测自定义 View 上的长按？

Question

我有一个扩展 FrameLayout 并实现 ScaleGestureDetector.OnScaleGestureListener 的自定义 View 。正如类名所暗示的那样，这个 View 是可缩放 + 可平移的。这是自定义 View 类:https://gist.github.com/Orbyt/23c82ce9002df6c318d4

我一直在努力寻找一种方法来检测对此 View 的长按。我知道，通常我可以在 Activity 中做这样的事情:

GestureDetector mGestureDetector = new GestureDetector(this, this);

mZoomableLayout.setOnTouchListener(new View.OnTouchListener()
{
    @Override
    public boolean onTouch(View v, MotionEvent event)
    {
        return mGestureDetector.onTouchEvent(event);
    }
});

mGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener()
{
    @Override
    public void onLongPress(MotionEvent e)
    {
      // do tasks here
    }
});

使用它，View 不再是可缩放的，大概是因为它拦截了所有的 onTouch 事件，而不是 Views 类内部的实现。

所以我的问题是，检测此 View 上的长按最干净的方法是什么？

Answer 1

我有一个捏缩放圆圈，我在上面检测到正常点击和长按。下面给出了代码 fragment 。在此，我通过 MotionEvent.ACTION_DOWN 和 MotionEvent.ACTION_UP 之间的时间间隔检测到长按和正常点击。

希望对您有所帮助。

     private static final int MAX_CLICK_DURATION = 200;
     private float mScaleFactor = 1.0000000f;
     private long mStartClickTime;


     @Override
     public boolean onTouchEvent(MotionEvent event) {
     float x = event.getX();
     float y = event.getY();
     boolean right = x > (screenWidthPX / 2 + ((mLayoutHeight / 4) + 20) * mScaleFactor);
     boolean left = x < (screenWidthPX / 2 - ((mLayoutHeight / 4) + 20) * mScaleFactor);
     boolean top = y > (mLayoutHeight / 2 + ((mLayoutHeight / 4) + 20) * mScaleFactor);
     boolean bottom = y < (mLayoutHeight / 2 - ((mLayoutHeight / 4) + 20) * mScaleFactor);


     if (event.getPointerCount() > 1) {
        if (left || right || top || bottom) {
            //  You may not need this condtion, I needed this because I had custom view of pinch zoom circle and, this condition detects the touch at outer area of circle.             
        } else {
            mScaleGestureDetector.onTouchEvent(event);
        }
     } else {
        switch (event.getAction()) {

            case MotionEvent.ACTION_DOWN: {
                mStartClickTime = Calendar.getInstance().getTimeInMillis();

                break;
            }
            case MotionEvent.ACTION_UP: {
                long clickDuration = Calendar.getInstance().getTimeInMillis() - mStartClickTime;

                if (clickDuration < MAX_CLICK_DURATION) {
                    if (left || right || top || bottom) {

                    } else {
                        Toast.makeText(mContext, "Normal CLick Detected", Toast.LENGTH_SHORT).show();
                    }
                 } else {
                    Toast.makeText(mContext, "Long CLick Detected", Toast.LENGTH_SHORT).show();

                }
            }
        }
    }
    return true;
}