I'm trying to paint a JPanel using Graphics2D, and I'd like the drawing to happen in a SwingWorker's done() method, after some math in doInBackGround(), but this seems to not draw anything?
What is wrong in my code?
class MyJanel extends JPanel {
@Override
public Dimension getPreferredSize() {
return new Dimension(800, 600);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
MyExecutor worker = new MyExecutor(g2);
worker.execute();
}
class MyExecutor extends SwingWorker<Void,Void> {
Graphics2D gRef;
int result;
public MyExecutor(Graphics2D g2){
gRef = g2;
}
@Override
protected Void doInBackground() {
result = 100+100;
return null;
}
@Override
protected void done() {
gRef.drawLine(20, 20, result, result);
}
}
}