Need a timed panel.repaint();

Question

I want my code to paint a panel, wait 1 second. Edit the panel by executing the function nextGen(); and repaint the panel. I want this function to happen 5 times. The problem is, everytime I try to do a try/catch thing with thread.sleep(), it "skips" over repaint, does nextGen(); and sleeps. Please help!

button3.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                for(int i = 0;i<5;i++) {
                    try {
                        Thread.sleep(1000);
                        nextGen();
                        panel.repaint();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                //System.exit(0);
            }
        });

https://stackoverflow.com/a/182422/85421 ; https://stackoverflow.com/a/14074427/85421 ; https://stackoverflow.com/a/7217210/85421 ; https://stackoverflow.com/q/16404023/85421 ; ... — user85421, Dec 10 '19 at 06:24

score 0 · Accepted Answer · answered Dec 10 '19 at 06:05

0

Use a Swing Timer...

Timer timer = new Timer(1000, new ActionListener() {
    private int count;
    @Override
    public void actionPerformed(ActionEvent evt) {
        nextGen();
        panel.repaint();
        count++;
        if (count >= 5) {
            ((Timer)evt.getSource()).stop();
        }
    }
});
timer.start();

See Concurrency in Swing for more information about the reason why you're having this particular issue and How to Use Swing Timers for more details about Swing Timer

answered Dec 10 '19 at 06:05

MadProgrammer

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:/ Did you forget to import `javax.swing.Timer`? Did you read the linked docs? Did you look at the linked examples? – MadProgrammer Dec 10 '19 at 06:33
Thanks a lot, it really helped! but if I were to make it a start/stop button, how would I do it? – Kaushal Ramesh Dec 10 '19 at 06:42
You would need to make the reference to `Timer` an instance field, so I could be accessed in a large scope. Then you can simply call `start`/`stop` as needed – MadProgrammer Dec 10 '19 at 06:45
I still don't quite understand. – Kaushal Ramesh Dec 10 '19 at 06:56
[For example](https://stackoverflow.com/questions/50408678/adding-resume-function-to-stopwatch/50409049#50409049) – MadProgrammer Dec 10 '19 at 08:02

Need a timed panel.repaint();

1 Answers1