问题
I'm making a component (extending JComponent) which will have some decoration drawn over the top of it and partly outside its bounds.
I would like to know if there's a way of drawing outside the component using self-contained code (I don't want to have to do any drawing in the parent container, for example).
回答1:
AFAIK, there is no easy solution. One way to achieve this is to draw on the container's GlassPane, as shown here. IMHO, I would just modify the Graphics object of the component to change the "apparent" bounds, which will enable you to draw stuff that's "outside the bounds" on the component itself.
来源：https://stackoverflow.com/questions/7970938/drawing-outside-a-components-bounds