Layering two Images with transparency

Question

Ok, so I have my own JComponent, and for the painting I have two Images.
The main one which contains all the stuff I want to paint, and the overlay which contains temporary thing I want on top of the main one.
To make this work, I need overlay to be transparent as it is drawn on top of the main one.
But for some reason I can not get this to work, the pixels in the overlay (and possibly the main) are completely opaque!
Here's the relevant code:
public void addNotify() {
          super.addNotify();
          Color trans = new Color(0, 0, 0, 0);
          image = createImage(WIDTH, HEIGHT);
          graphics = image.getGraphics();
          graphics.setPaintMode();
          graphics.setColor(trans);
          graphics.fillRect(0, 0, WIDTH, HEIGHT);
          overlay = createImage(WIDTH, HEIGHT);
          overlayGraphics = overlay.getGraphics();
          overlayGraphics.setPaintMode();
          overlayGraphics.setColor(trans);
          overlayGraphics.fillRect(0, 0, WIDTH, HEIGHT);
          setBackground(Color.WHITE);
public void paint(Graphics g) {
          g.drawImage(image, 0, 0, this);
          g.drawImage(overlay, 0, 0, this);
}Can anyone help me get this to work?

Answer 1

1. For custom painting in JComponent, override paintComponent(...), not paint(...)
2. Painting a transparent rectangle over an opaque background isn't going to automagically make the overlay image transparent. You have omitted to post the most relevant part of your code, namely the createImage(...) method, so we don't even know whether you have an Image type that supports transparency.
db