— Scott McNealy, Sun Microsystems Chairman, President and ceo

making a drawing 
panel
import java.awt.*;
import javax.swing.*;
class MyDrawPanel extends JPanel {

public void paintComponent(Graphics g) {
g.setColor(Color.orange);
g.fillRect(20,50,100,100);
}
}
you need both of these
Make a subclass of JPanel, a widget 
that you can add to a frame just like 
anything else. Except this one is your 
own customized widget.
This is the Big Important 
Graphics method. 
You will NEVER call this yourself. The 
system calls it and says, “Here’s a nice 
fresh drawing surface, of type Graphics, 
that you may paint on now.”.
Imagine that ‘g’ is a painting machine. You’re 
telling it what color to paint with and then 
what shape to paint (with coordinates for 
where it goes and how big it is)

---

getting 
gui
you are here
4
365
Let’s look at a few more things you can do in paintComponent(). 
The most fun, though, is when you start experimenting yourself. 
Try playing with the numbers, and check the API for class 
Graphics (later we’ll see that there’s even more you can do besides 
what’s in the Graphics class).
Fun things to do in paintComponent()
public void paintComponent(Graphics g) {
Image image = new ImageIcon(“catzilla.jpg”).getImage();
g.drawImage(image,3,4,this);

}
public void paintComponent(Graphics g) {

g.fillRect(0,0,this.getWidth(), this.getHeight());

int red = (int) (Math.random() * 255);
int green = (int) (Math.random() * 255);
int blue = (int) (Math.random() * 255);
Color randomColor = new Color(red, green, blue);