Java - Make corners of JWindow 100% transparent on MacOS (Snow leopard)

I am trying to make a small java application, and I need the corners of a JWindow to be 'cut' off, in a 45 degree angle.

I have tried using the AWTUtilities.setWindowShape, but apparently it is not supported by MacOS (snow leopard).

Does anyone know how to s开发者_如何转开发olve this problem?? Any help will be very appreciated.

How to Create Translucent and Shaped Windows

The link above should help you a lot, I used that tutorial once before. Made by Sun!