PaintComponent help

Question

I guess my confusion comes from not really understanding when paintComponent method is called. I am trying to draw a polygon on an image(in a JLabel) AFTER the image is displayed. I wrote the following small extension to JLabel(notice the I call paintComponent from drawRegion):
class NVOImageMap extends JLabel {
public int raLength;
public int decLength;
final Color bg = Color.yellow;
final Color fg = Color.yellow;
public void NVOImageMap() {
setBackground(bg);
setForeground(fg);
public void drawRegion(int [] x, int [] y){
Graphics g = this.getGraphics();
// g.setColor(Color.yellow);
// g.drawPolygon(x, y, x.length);
this.paintComponents(g,x,y);
public void paintComponents(Graphics g,int [] x, int[] y) {
super.paintComponent(g); //clears the background
g.setColor(Color.yellow);
g.drawPolygon(x, y, x.length);
and in my main program I have
backGround.setIcon("background.gif");
<code to get some region>
backGround.drawRegion(x,y);
what happens when this method is invoked is the polygon appears for a split second and then disappears. Can someone explain to me why this is happening?.

Answer 1

Seems weird. Just some ideas:
You must never call 'paintComponent' by yourself. Just overwrite that method like:
public void paintCompoenent( Graphics g ) {
super.paintComponent ( g );
myDraw ();
to force a redraw just call 'repaint ();' in your main program. The Swing renderer will then call 'paintComponent' recursively down all children of 'contentPane'