I intend to use a JInternalFrame as a modal JDialog in full-screen mode, however, it is not currently being shown when it gets called. Do I need to add it to some container? I tried adding it to a JOptionPane.showInternalMessage(…), but since I want to make the dialog to go away automatically after 3 seconds, this would not work, as the the JOptionPane dialog would just stay there until someone clicks OK.
Any idea? Many thanks.
Yes you have to add it to a container in which you want it to be ‘internal’.
Below you have an example which shows you this behaviour. You can notice here that the internal frame (which will appear/hide on mouse press inside the frame) is not painted over the EAST panel, as it is clipped when it goes outside the borders of its parent.