Java efficient overlay over transparent components

I have a custom JComponent that performs come complicated painting. It is set to non-opaque so that the background of its parent shows through the parts it does not paint.

I need an mouse overlay (a simple shape) that follows the mouse. It really shouldn't need to repaint the component below it every time the mouse 开发者_JS百科moves. So I'm thinking to buffer the JComponent but because it's non-opaque, calling .paint(buffer) will not paint the background of the parent.

Any ideas?

Thanks in advance.

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I have a custom JComponent that performs come complicated painting.

Maybe your complication painting can be done to a BufferedImage. Then the component just draws the image so you don't have to invoke the complicated code every time. The image would be recreated whenever properties affecting the image are changed.

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May me you can use JWindow. Just make it visible and change position of the JWindow on mouse move?