Copying panel contents to an image.

I'm trying to copy panel contents to an image I'm using the following code and the string "blah" gets drawen on the image. When I try and paint the image back onto the panel it paints an image with the same color as the panel background and also the text "blah"
The thing is I drawlines onto the panels graphics in another procedure but it doesn't seem to copy those lines to the image.
Anyone know why???

Originally posted by Archer DaPunk:

The thing is I drawlines onto the panels graphics in another procedure but it doesn't seem to copy those lines to the image.

What is this other procedure and when is it called?

. . . drawLine((Graphics2D) tPanel.getGraphics(), 50, 50, 100, 100, 4); . . . g2.drawImage(image, 100, 100, this);

What are you invoking drawLine() on? I think you may be writing your lines directly on the panel, then overwriting them with the g2.drawImage() call.

This is how I call the .drawline()
I send drawLine the Graphics i want to draw onto ie. tPanel.getGraphics()
I don't fully understand what all the sin and cos maths are for but it works. I got this code from my sample API for smartboards (electronic whiteboards)
I want to be able to copy these lines that i draw into an image so i can redraw it back onto the panel with an alpha channel and then still be able to draw on the panel with the smartboard.

public static JPanel tPanel = new JPanel();

public void mouseDragged(MouseEvent e) {
Graphics2D g = (Graphics2D) tPanel.getGraphics();
g.setColor(m_CurrentColor);
int thickness = m_penThick;
drawLine(g, lastPoint.x, lastPoint.y, e.getX(), e.getY(), thickness);
}
    public void drawLine(Graphics2D g, int x1, int y1,
                         int x2, int y2, int lineWidth) {
        double angle;
        double Delta_x = (double) (x2 - x1);
        double Delta_y = (double) (y2 - y1);
        double R = ((double) lineWidth) / 2.0;
        double cosAngle, sinAngle, Double_I;
        //Graphics2D g = (Graphics2D) tPanel.getGraphics();
        g.setStroke(currentStroke);
        if (x1 == x2) {
            angle = Math.PI;
        } else {
            angle = Math.atan(Delta_y / Delta_x) + Math.PI / 2;
        }
        cosAngle = Math.cos(angle);
        sinAngle = Math.sin(angle);
        x1 = x1 - (int) (R * cosAngle);
        x2 = x2 - (int) (R * cosAngle);
        y1 = y1 - (int) (R * sinAngle);
        y2 = y2 - (int) (R * sinAngle);
        for (int I = 0; I < lineWidth; I++) {
            Double_I = (double) I;
            g.drawLine(x1 + (int) (Double_I * cosAngle),
                    y1 + (int) (Double_I * sinAngle),
                    x2 + (int) (Double_I * cosAngle),
                    y2 + (int) (Double_I * sinAngle));
           if ((I + 1) < lineWidth) {
                g.drawLine(x1 + 1 + (int) (Double_I * cosAngle),
                        y1 + (int) (Double_I * sinAngle),
                        x2 + 1 + (int) (Double_I * cosAngle),
                        y2 + (int) (Double_I * sinAngle));
            }
        }
    }

[ October 13, 2003: Message edited by: Archer DaPunk ]