Remember that Sun led by example.
com.sun.java.swing.plaf.nimbus.InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonPainter, anyone?
http://javadoc.bugaco.com/com/sun/java/swing/plaf/nimbus/Int...
com.sun.java.swing.plaf.nimbus.InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonPainter, anyone?
http://javadoc.bugaco.com/com/sun/java/swing/plaf/nimbus/Int...
I don't really see that class as a problem.