android - onLongPress 后继续 onScroll 事件

Question

有谁知道如何结合使用 onLongPress(MotionEvent e) 和 onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)？想法是从 onLongPress 开始，但继续滑动某些 View 。

我目前的代码:

private class CustomListener implements View.OnTouchListener {

    ImagePreviewer imagePreviewer = new ImagePreviewer();

    private GestureDetector gestureDetector = new GestureDetector(getActivity(), new GestureDetector.SimpleOnGestureListener() {

        ImageView currentImageView;

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {

            float x = e2.getX();
            float y = e2.getY() + mConstraintLayoutContainerCoordinates[1];

            currentImageView = getProperImage(mCurrentImagesNumberForPoll, (int) x, (int) y);

            if(currentImageView != null) {
                imagePreviewer.show(getActivity(), currentImageView);
            }

            return super.onScroll(e1, e2, distanceX, distanceY);
        }

        @Override
        public void onLongPress(MotionEvent e) {

            Log.d(TAG, "LONG PRESS");

            float x = e.getX();
            float y = e.getY() + mConstraintLayoutContainerCoordinates[1];
            currentImageView = getProperImage(mCurrentImagesNumberForPoll, (int) x, (int) y);
            if(currentImageView != null) {
                imagePreviewer.show(getActivity(), currentImageView);
            }

            super.onLongPress(e);
        }
    });

    @Override
    public boolean onTouch(View v, MotionEvent event) {

        if(event.getAction() == MotionEvent.ACTION_UP || event.getAction() == MotionEvent.ACTION_CANCEL) {
            Log.d("TAG", "DOWN  or CANCEL ");
            imagePreviewer.hide();
        }
        gestureDetector.onTouchEvent(event);
        return true;
    }
}

事情是 onScroll() 被调用(当我在 View 上滑动手指时)或 onLongPress()，但我想从 onLongPress 开始()，然后检测滑动，这样我就可以选择适当的 View 来相应地显示。

Answer 1

GestureDetectorCompat 在检测到 onLongPress 后阻止调用 onScroll。可以通过向检测器发送 ACTION_CANCEL 来取消阻止。

@Override
public void onLongPress(MotionEvent e) {
    isLongPressed = true;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    if (detector.onTouchEvent(event)) {
        return true;
    }

    switch (event.getActionMasked()) {
        case MotionEvent.ACTION_MOVE:
            if (isLongPressed) {
                isLongPressed = false;
                MotionEvent cancel = MotionEvent.obtain(event);
                cancel.setAction(MotionEvent.ACTION_CANCEL);
                detector.onTouchEvent(cancel);
            }
            break;
    }
    return super.onTouchEvent(event);
}