Question

In my android application.I have a panorama view, in this view i want to avoid only vertical scrolling. So i disabled it using onTouchEvent(MotionEvent event) method.

Hear is the code.

    @Override
public boolean onTouchEvent(MotionEvent event) {
    if( event.getAction()==MotionEvent.ACTION_UP){
        Log.d(TAG, "onTouchEvent:ACTION_UP");
        return false;
    }else if(event.getAction()==MotionEvent.ACTION_DOWN){
        Log.d(TAG, "onTouchEvent:ACTION_DOWN");     
        return false;
    }else{
        Log.d(TAG, "onTouchEvent:ACTION_UNKWON");
        return super.onTouchEvent(event);
    }

}

but it disables scrolling horizontally also.How can i solve this??

Answer 1

I think you misunderstood the notion of ACTION_DOWN and ACTION_UP.

ACTION_DOWN means when your finger touches the touchscreen, ACTION_UP is when you lift your finger from the touchscreen.

That said, you can indicate in ACTION_DOWN that the motion event started, check in ACTION_MOVE the direction of the touch event from the coordinates and decide whether you want to block the movement or not, and reset your variables in ACTION_UP.

float startX
float startY;   

@Override
public boolean onTouchEvent(MotionEvent event) {

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        startX = event.getX();
        startY = event.getY();
        break;
    case MotionEvent.ACTION_MOVE:
        float currentX = event.getX();
        float currentY = event.getY();

        float diffX = Math.abs(currentX - startX);
        float diffY = Math.abs(currentY - startY);

        // The purpose of the +100 is to make sure that we have a big enough
        // difference between the 2 directions, eg. it's not diagonal
        if(diffY > diffX + 100){
            return false;
        }
        break;
    case MotionEvent.ACTION_POINTER_UP:

        break;
    }

    return true;
}