Java pause program until a label-image is pressed

Question

I created a JFrame with some labels on it and i want my program to pause until a certain label is clicked. Here 's my code:

package test;

import java.awt.BorderLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;


public class GUI {


public GUI(){

}

private void createFrame(){
    JFrame frame=new JFrame("TEST");
    JLabel label1=new JLabel("LABEL1");
    JLabel label2=new JLabel("LABEL2");
    JLabel label3=new JLabel("LABEL3");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(500,500);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
    frame.add(label1,BorderLayout.PAGE_START);
    frame.add(label2,BorderLayout.CENTER);
    frame.add(label3,BorderLayout.PAGE_END);

    label1.addMouseListener(new MouseAdapter(){
        @Override
         public void mouseClicked(MouseEvent e) {
                //do something
            }
    });

    label2.addMouseListener(new MouseAdapter(){
        @Override
         public void mouseClicked(MouseEvent e) {
                //return to start()
            }
    });

    label3.addMouseListener(new MouseAdapter(){
        @Override
         public void mouseClicked(MouseEvent e) {
                //do something
            }
    });
}

public void start(){
    createFrame();
    System.out.println("DONE");
}
}

I don't want "DONE" to be printed before i click on label2. How can I make the program wait until label2 is clicked?

Answer 1

Add a flag in the listener, that toggles it on the click.

boolean clicked = false;
label2.addMouseListener(new MouseAdapter(){
        @Override
         public void mouseClicked(MouseEvent e) {
                //return to start()
                clicked = true;
            }
    });

And before printing "DONE", sleep on it.

while(clicked == false){
    try {
       Thread.sleep(200);
    } catch(InterruptedException e) {
    }
}

Make sure the flag is volatile