public void shiftLeft(boolean isJump){
		reDrawIndex = reDrawIndex - 5;
		if(reDrawIndex < 0){
			reDrawIndex = files.size() + reDrawIndex;
		}
		
		if(isJump){
			listPosition = listPosition - 5;
			if(listPosition < 0){
				listPosition = files.size() + listPosition;
			}
		}
	}