Custom Java Swing Meter Control

Question

I\'m trying to make a custom swing control that is a meter. Swing Meter http://dl.dropbox.com/u/2363305/Programming/Java/swing_meter.gif

The arrow will move up and d

Answer 1

You could use a JSlider and use setValue(int n) to set the value whenever you need. You can also change the default appearance, so you get an arrow and a gradient as you want.

Answer 2

In addition to @Jonas' example, you might like to look at the article How to Write a Custom Swing Component.

Addendum: On reflection, it looks a little intimidating, but you can extend BasicSliderUI and reuse some of your code in paintThumb() and paintTrack().

JSlider slider = new JSlider();
slider.setUI(new MySliderUI(slider));
...
private static class MySliderUI extends BasicSliderUI {

    public MySliderUI(JSlider b) {
        super(b);
    }

    @Override
    public void paintTrack(Graphics g) {
        Graphics2D g2d = (Graphics2D) g;
        Rectangle r = trackRect;
        g2d.setPaint(new GradientPaint(
            r.x, r.y, Color.red, r.x + r.width, r.y + r.height, Color.blue));
        g.fillRect(r.x, r.y, r.width, r.height);
    }

    @Override
    public void paintThumb(Graphics g) {
        super.paintThumb(g); // replace with your fill() 
    }
}