@Override
	public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
		int height = 10;
		int count = getComponentCount();
		if (count > 0) {
			count = Math.min(getStep(), count);
			for (int i = 0; i < count; i++) {
				int tmp = getComponent(i).getHeight();
				if (tmp > height) {
					height = tmp;
				}
			}
		}
		return height;
	}