How to make the main GUI thread 'wait' until a separate pop-up window is disappeared

Question

I have an object which is invoked from the main GUI thread and shows a separate JFrame for a number of seconds and then disappear (with the use of a timer). Now I want to make t

Answer 1

Don't use a separate JFrame for this is what modal dialogs were built for. Use either a JOptionPane or a modal JDialog.