CODEWITHSUNDEEP
javaswingtimertimertask
Claudiga
Claudiga

Reputation: 437

How to stop timer in a swing application

I wrote a little code to change the colours of a few buttons to stimulate a random sequence offlashing colours. i have set a timer to do this for me but i just dont know how to stop it

Heres my code 

          Timer timer = new Timer(100, new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        int buttons[] = new int[9];

                        for (int j = 0; j < buttons.length; j++) {

                        //  System.out.println("times");
                            Component button = frame.getContentPane().getComponent(j);
                            int Red = new Random().nextInt(255 - 1) + 1;
                            int Green = new Random().nextInt(255 - 1) + 1;
                            int Blue = new Random().nextInt(255 - 1) + 1;

                            button.setBackground(new Color(Red, Green, Blue));

                            SwingUtilities.updateComponentTreeUI(button);

                        }

                    }// }

                }); timer.start();

Upvotes: 2

Views: 645

Answers (1)

d.j.brown
d.j.brown

Reputation: 1842

There's a few ways you can do it, here's a couple of quick approaches.

One method is by utilising System.currentTimeMillis():

private Timer timer;
private final int DELAY = 100;
private final int DURATION = 10_000;
private long startTime;

public void timerExample() {
    timer = new Timer(DELAY, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (System.currentTimeMillis() >= startTime + DURATION) {
                System.out.println("Done");
                timer.stop();
            } else {
                System.out.println("Tick");
            }
        }
    });
    startTime = System.currentTimeMillis();
    timer.start();
}

This one will stop the Timer if the current time is greater than the startTime + DURATION.

Another method is this use of a counter:

private Timer timer;
private final int DELAY = 100;
private final int DURATION = 10_000;
private final int TOTAL_TICKS = DURATION / DELAY;
private int tickCounter = 0;

public void timerExample() {
    timer = new Timer(DELAY, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (++tickCounter == TOTAL_TICKS) {
                System.out.println("Done");
                timer.stop();
            } else {
                System.out.println("Tick");
            }
        }
    });
    timer.start();
}

With DELAY as 100ms and DURATION as 10,000ms you can calculate the total number of Timer ticks required e.g. 10,000 / 100 = 100 ticks.

Each time action listener is fired, it checks if the total number of ticks are reached, and if so stops the timer.

Upvotes: 2

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