Changing The Underlying Background Color Of A Swing Window

Question

As discussed here, when resizing a Swing application in Vista (and Windows 7, which is what I\'m using) you get a black background in the right/bottom corner while Swing\'s

Answer 1

The frame is responsible for painting its background so you need to make sure you let it do its job.

You demonstrate this by setting:

System.setProperty("sun.awt.noerasebackground", "true");

This will cause the background to always be black on resize expansions. (So don't do it.)

The following worked for me:

1. (AWT only) Set up double buffering using createBufferStrategy(2) - wrapped in addNotify() otherwise you'll run into exceptions during Frame creation

   (Step 1 is only necessary in AWT as Swing is double buffered by default.)

2. Always (important) call super() in your Frame.paint() implementation

3. Set the background colour with setBackground() then the background should always be the same colour when expanding the frame

Sample code:

    class InnerFrame extends Frame {
        public void addNotify() {
            super.addNotify();
            // Buffer
            createBufferStrategy(2);           
            strategy = getBufferStrategy();
        }

        public void paint(Graphics g) {
            super(g);
            //...
        }
        //...
     }