I want my panel to fit the frame when I show/hide fields. How could I notify to the parent frame to revalidate?
I thought about pass the frame to my panel's constructor, but I think may have a way this is already done. I remember that there was a protected attribute in JPanel, but there isn't.. maybe i remembering the wrong component.
I need show/hide some fields of my panel, and I want the panel to fit the frame.
You mean like a summary/details view and you want the frame size to change? Then try:
SwingUtilities.windowForComponent(...).pack();