Make JSlider move constantly

Question

I have this piece of code:

Timer timer;
ActionListener listener;
listener = new ActionListener() {
    int counter = 0;

    public void actionPerformed(ActionEvent ae) {
        counter++;
        jSlider1.setValue(counter);
        jSlider2.setValue(counter);
        jSlider3.setValue(counter);
        jSlider4.setValue(counter);
        jSlider5.setValue(counter);
        jSlider6.setValue(counter);
        jSlider7.setValue(counter);
        jSlider8.setValue(counter);
        jSlider9.setValue(counter);
        jSlider10.setValue(counter);
    }
};
timer = new Timer(50, listener);
timer.start();

The JSLider moves automatically.

How to make the slider so that when it reaches the end, it goes back to the beginning?

1) ***Why?*** It sounds like you're trying to reinvent an indeterminate `JProgressBar`. 2) For better help sooner, post a [MCVE] or [Short, Self Contained, Correct Example](http://www.sscce.org/). — Andrew Thompson, May 10 '18 at 08:06
@chicoo Yes and no. Swing is NOT thread safe, so you shouldn't update the UI from outside the context of the Event Dispatching Thread. For that, you should be using a `SwingWorer` — MadProgrammer, May 11 '18 at 21:45

score 1 · Answer 1 · answered May 10 '18 at 00:25

reverse the counter

So, you need some value which dictates the amount to add/subtract from the counter on each tick. You probably also need to know the min/max range the counter can travel through.

To this end, a simple delta value, which gets added to the counter and which can be inverted (+/-) when the counter reaches either end of the available range.

Maybe something like...

listener = new ActionListener() {
    int counter = 0;
    int delta = 1;

    int min = 0;
    int max = 100;

    public void actionPerformed(ActionEvent ae) {
        counter += delta;
        if (counter < min || counter > max) {
            delta *= -1;
        }
        counter = Math.min(max, Math.max(min, counter));

        jSlider1.setValue(counter);
        jSlider2.setValue(counter);
        jSlider3.setValue(counter);
        jSlider4.setValue(counter);
        jSlider5.setValue(counter);
        jSlider6.setValue(counter);
        jSlider7.setValue(counter);
        jSlider8.setValue(counter);
        jSlider9.setValue(counter);
        jSlider10.setValue(counter);
    }

};

Make JSlider move constantly

1 Answers1