code: public void show(Activity activity, int x, int y, int gravity){
  		if(getParent() == null){
  			FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(mBackground.getIntrinsicWidth(), mBackground.getIntrinsicHeight());
  			updateParams(x, y, gravity, params);
  
  			activity.getWindow().addContentView(this, params);
  		}
  		else
  			updateLocation(x, y, gravity);
  	}
docs: Show this button at the specific location. If this button isn't attached to any parent view yet,
  it will be add to activity's root view. If not, it will just update the location.
  @param activity The activity that this button will be attached to.
  @param x The x value of anchor point.
  @param y The y value of anchor point.
  @param gravity The gravity apply with this button.
  
  @see Gravity