Re: How an I use a copy o
To: comp.lang.java.gui
djubre@myway.com wrote:
Knute Johnson wrote:
That is not how it works. The component's Graphics is used to draw on
it. Why don't you just put the JPanel with the drawing on it where you
want it to show up?
I need the Graphics2D instance to do some modifications. I can't change
the original renedering because it is not my code.
All I can do is obtain the Graphics2D instance with getGraphics(), and
hope I can do someting with it.
Can I make an image out of the Graphics2D instance.
I think of the Graphics2D instance as a drawing surface. Can I
transform it to an image? Can I use it somewhere else, after all the
drawings were done.
Extend the component that you want to draw on, call
super.paintComponent() from the new components paintComponent method and
then draw away. This isn't going to work if it is some sort of active
component like a button or something.
import java.awt.*;
import javax.swing.*;
public class test {
public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
class OriginalThing extends JPanel {
public OriginalThing() {
setPreferredSize(new Dimension(400,300));
}
public void paintComponent(Graphics g) {
g.setColor(Color.BLUE);
g.fillRect(0,0,getWidth(),getHeight());
}
}
class ThingIWantToDrawOnToo extends OriginalThing {
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawString("I drew this on the original!",20,30);
}
}
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new ThingIWantToDrawOnToo());
f.pack();
f.setVisible(true);
}
};
EventQueue.invokeLater(r);
}
}
--
Knute Johnson
email s/nospam/knute/
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