code: public void setItemSize(int columnWidth, int columnHeight) {
  
  		if (itemWidth == columnWidth) {
  			return;
  		}
  
  		itemWidth = columnWidth;
  		itemHeight = columnHeight;
  
  		itemLayoutParams = new GridView.LayoutParams(itemWidth, itemHeight);
  
  		notifyDataSetChanged();
  	}
docs: Reset colum size
  
  @param columnWidth