Question

I am trying to have my program break out of a while loop when a button on the gui is pressed.

I have a thread which launches the GUI thread and the waits until an apply button is pressed.
Here is the code:

public void run() {     

        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }           
        });

        // Wait until apply button clicked and set team
        while(true) {

            applyClicked = gui.getApplyClicked();
            if (applyClicked == true) {
                teamYellow = gui.getTeam();
                break;
            }   
        }

However even when I click apply and the applyClicked becomes true within the GUI it does not execute that if statement.

However if I add a print line underneath the while true it works ok.

I also debugged it running line by line and the variables set correctly and it works.

Why doesn’t this work when I don’t have a println? Is it something to do with threads?

Thanks

Answer 1

You’re executing a busy-wait loop, which will I guess take all of your cpu power.
You should instead add an actionListener on your apply-button and do your stuff in the actionPerformed method.