Question:
Is there any way I can make a JFrame look like JInternalFrame? It looks bad at runtime when you change the look-and-feel, but the main
frame doesn't change.
Answer:
This is currently a deficiency in the Swing classes. A top level
window is forced to assume the look-and-feel of the native window
system. There is no technical reason why it would not be possible
to make a borderless frame part of the standard classes. It could
provide its own titlebar, border, and other decorations.
However, doing this would disable the native window manager operations, such
as right-clicking on the titlebar in Windows 95/98/NT. This appears
to be why it wasn't done.