Create a clear button that will clear a jpanel

Question

so i have two classes. One being a frame, and the other being a panel.
On the panel, i can draw various shapes with various colours etc. The frame contains the panel, and also a north panel containing various buttons to achieve this.
What i would i need to do is create a clear button that will clear the panel.
I know i can go and set it so it's draws a rectangle the same colour as the background but that would be cheating.
I will post a section of the paint just so you get an idea.
    public void paintComponent(Graphics gPanel) {
        if (this.buffer == null) {
            Dimension d = getSize();
            this.buffer = new BufferedImage(d.width, d.height,
                    BufferedImage.TYPE_INT_ARGB_PRE);
            myLineColour = new Color(0, 255, 0);     // initial colour for drawing
            this.g2Buffer = (Graphics2D) this.buffer.getGraphics();
            this.g2Buffer.setColor(Color.white);
            this.g2Buffer.fillRect(0, 0, d.width, d.height);
            // This time we'll draw with a broad pen 
        g2Buffer.setStroke(new BasicStroke(myLineWidth));
        if (myShapeFlag == 1){{
            this.g2Buffer.setColor(Color.white);
            g2Buffer.setXORMode(myLineColour); //go into the overwrite mode
            g2Buffer.drawLine(xStart, yStart, xOld, yOld); // undraw last
            g2Buffer.drawLine(xStart, yStart, xEnd, yEnd);     // draw new
            g2Buffer.setPaintMode();          // out of XOR overwrite mode
            xOld = xEnd;                    // store last end point
            yOld = yEnd;
        if(mouseReleased) {          // final time through
            g2Buffer.setColor(myLineColour);
            g2Buffer.drawLine(xStart, yStart, xEnd, yEnd);     // draw final
            mouseReleased = false;
        gPanel.drawImage(this.buffer, 0, 0, this); }Any help on this would be much appreciated

Answer 1

no idea how to do this.. sorry...
for the jbutton action listenener i'm not sure.
I think i'm on the right tracks with a method
    public void clearPanel(Graphics gPanel){
            g2Buffer.fillRect(100,100,100,100);     // draw final
            gPanel.drawImage(this.buffer, 0, 0, this);
}but again i think i'm way off the mark..