How can I detect tap on the screen?

Question

More specific where do I attach OnGestureListener so that
I can detect onSingleTapUp everywhere on the screen,
even if an ImageView take up half the screen.

Now I have the Listener on the Activity that has an ImageView.
But the Listener only fire when I click outside the ImageView.

I read and try to understand this but cannot get it right.

this code is in the Activity.

 public boolean onSingleTapUp(MotionEvent e) {
    //addtext.setText("-" + "SINGLE TAP UP" + "-");
    //Log.d(TAG, "- + SINGLE TAP UP + - ***********************************************************************");  
    int btnsize = buttonSave.getHeight();
    int viewWidth = display.getWidth();
    int viewHeight = display.getHeight();

    // RIGHT SIDE SCREEN
    if(e.getX()> (viewWidth*0.7)){
        Log.d(TAG, "RIGHT SIDE");
        if(e.getY()> viewHeight*0.7){         
            Log.d(TAG, "right down on screen");
        }else if(e.getY()> (viewHeight*0.45)){ 
            Log.d(TAG, "right middle on screen   ");
        }
    }
    // LEFT SIDE SCREEN
    if(e.getX()< (viewWidth*0.3)){
        Log.d(TAG, "LEFT SIDE");
        if(e.getY()> viewHeight*0.7){ 
            Log.d(TAG, "Left middle on screen  ");
        }else if(e.getY()> (viewHeight*0.45)){
            Log.d(TAG, "Left down on screen ");
        }
    }
    return true;
}

Answer 1

I'm answering my own question. Thanks to the above @Jason. I have registered onTouchEvent to all views.
It works great.