code511788465541441 code511788465541441 - 1 month ago 13
Android Question

How can I detect a click in an onTouch listener?

I have a

ViewPager
inside a
ScrollView
. I need to be able to scroll horizontally as well as vertically. In order to achieve this had to disable the vertical scrolling whenever my
ViewPager
is touched (
v.getParent().requestDisallowInterceptTouchEvent(true);
), so that it can be scrolled horizontally.

But at the same time I need to be able to click the viewPager to open it in full screen mode.

The problem is that onTouch gets called before onClick and my OnClick is never called.

How can I implement both on touch an onClick?

viewPager.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
System.out.println("TOUCHED ");
if(event.getAction() == MotionEvent.???){
//open fullscreen activity
}
v.getParent().requestDisallowInterceptTouchEvent(true); //This cannot be removed
return false;
}
});

viewPager.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
System.out.println("CLICKED ");
Intent fullPhotoIntent = new Intent(context, FullPhotoActivity.class);
fullPhotoIntent.putStringArrayListExtra("imageUrls", imageUrls);
startActivity(fullPhotoIntent);
}
});

Answer

Masoud Dadashi's answer helped me figure it out.

here is how it looks in the end.

viewPager.setOnTouchListener(new OnTouchListener() {
            private float startX;
            private float startY;
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    startX = event.getX();
                    startY = event.getY();
                    break;
                case MotionEvent.ACTION_UP: {
                    float endX = event.getX();
                    float endY = event.getY();
                    if (isAClick(startX, endX, startY, endY)) { 
                        launchFullPhotoActivity(imageUrls);// WE HAVE A CLICK!!
                    }
                    break;
                }
                }
                v.getParent().requestDisallowInterceptTouchEvent(true); //specific to my project
                return false; //specific to my project
            }

.

private boolean isAClick(float startX, float endX, float startY, float endY) {
    float differenceX = Math.abs(startX - endX);
    float differenceY = Math.abs(startY - endY);
    if (differenceX > C.CLICK_ACTION_THRESHHOLD/* =5 */ || differenceY > C.CLICK_ACTION_THRESHHOLD) {
      return false;
    }
   return true;
} 
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