How to make JFrame wait for input before the user can proceed?

Question

I'm making a question and answer game. The user must first pick a category in a JFrame then another Jframe would pop up with the question. What i want is to prevent the user from choosing another category without first answering the question.

Answer 1

Instead of using JFrame either use a JDialog or JOptionPane

See How to use dialogs for more details

Answer 2

You could make the second frame modal so that no category could be picked if the second frame is not closed first.

Answer 3

Disable the parent frame(Category) before showing the question frame

parentFrame.disable();
//Display yours Question Frame

Then you can add enable the category frame when user answers the question. use action Listeners for this. Also add a action lintener for close window button. In all these scenarios set visibility of your question frame to false and enable your categories frame.

parentFrame.enable();