Rounded popup for JCombobox

Question

I'm using nimbus as L&F, but I really like to have a rounded shape combobox dropdown like seaglass L&F. See following images.

Nimbus

Seaglass

How can I achieve that effect? Is overriding paint helpful here? What would a method be?

Answer 1

Nimbus can be customized by updating UIManager properties. Example:

UIManager.put("nimbusBase", new Color(...));
UIManager.put("nimbusBlueGrey", new Color(...));
UIManager.put("control", new Color(...));

Painters can be updated as well. For example, custom slider:

The actual approach:

sliderDefaults.put("Slider.thumbWidth", 20);
sliderDefaults.put("Slider.thumbHeight", 20);
sliderDefaults.put("Slider:SliderThumb.backgroundPainter", new Painter() {
  public void paint(Graphics2D g, JComponent c, int w, int h) {
     g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
     g.setStroke(new BasicStroke(2f));
     g.setColor(Color.RED);
     g.fillOval(1, 1, w-3, h-3);
     g.setColor(Color.WHITE);
     g.drawOval(1, 1, w-3, h-3);
   }
});

Resources:

• See complete example here: Skinning a slider with nimbus
• Nimbus defaults are listed here: Nimbus Defaults