JPanel size by inner components

Question

Is it possible to tell JPanel to set its size to fit all components that it contains? Something like pack() for JFrame.

edit: The trick with preferredSize d

Answer 1

The javax.swing mysteries reveal themselves only gradually, and only to those who are prepared to offer many libations (particularly torn out clumps of hair, hours burning the midnight oil, etc.) to the gods of Swing.

However, for this case in point I would suggest the following as a sort of Swiss army knife which usually does what you think the framework should do anyway:

myJPanel.getTopLevelAncestor().validate()

As the sacred text says, "Validates this container and all of its subcomponents." (Container.validate). NB getTopLevelAncestor() is a JComponent method.

Can't remember how JSplitPane fits into this: try it and you'll probably find that it validates both components (right and left, top and bottom), but I would be surprised if changing the divider doesn't do this for you anyway.