Cannot change colors in Image

Question

Hi All,
I really don't know any further in that problem, it can only be a small thing, but I don't come behind:
I'm creating a JPanel component with its own paingComponent method so that I can draw some things within that component:
JPanel p = new JPanel() {
               Image baseIm;
               public void paintComponent(Graphics g) {
                    super.paintComponent(g);
                                Image im = createImage(getWidth()-10,getHeight()-10);
                                im.getGraphics().setColor(new Color(255,0,0));
                                im.getGraphics().drawLine(0,0,100,100); // as an example
                    g.drawImage(im,5,5,this);
          };This always produces me a line, but in black color instead of red!
I tried it also with setColor(Color.RED), and with fillRect, but it is everytime the same: Every color I set to the Image's Graphics component is interpreted as black.
Setting the color directly on the JPanel's Graphics class is working fine, but this is not that what I want.
Has anyone an idea?
thanks in advance
alex,

Answer 1

the "getGraphics" method creates a new graphics object and disposes of the old one. So when you call "getGraphics" make sure to retain the Graphics object returned and use it until you're finished.
On another note, you should probably not create a new image within the paintComponent method every time, just once, like this:JPanel p = new JPanel() {
               Image baseIm;
               public void paintComponent(Graphics g) {
                    super.paintComponent(g);
                    if (baseIm == null)
                         baseIm = createImage(getWidth()-10,getHeight()-10);
                    Graphics gImage = baseIm.getGraphics();
                                gImage.setColor(new Color(255,0,0));
                                gImage.drawLine(0,0,100,100); // as an example
                    g.drawImage(im,5,5,this);
          };