Java Reference
In-Depth Information
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DVANCED
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OPIC
2.2: Applets
In the preceding section, you learned how to write a program that displays graphical
shapes. Some people prefer to use applets for learning about graphics programming.
Applets have two advantages. They don't need separate component and viewer
classes; you only implement a single class. And, more importantly, applets run
inside a web browser, allowing you to place your creations on a web page for all the
world to admire.
Applets are programs that run inside a web browser.
To implement an applet, use this code outline:
public class MyApplet extends JApplet
{
public void paint(Graphics g)
{
//
Recover
Graphics2D
Graphics2D g2 = (Graphics2D) g;
//
Drawing instructions go here
. . .
}
}
This is almost the same outline as for a component, with two minor differences:
1. You extend
JApplet
, not
JComponent
.
2. You place the drawing code inside the
paint
method, not inside
paintComponent
.
The following applet draws two rectangles:
ch02/applet/RectangleApplet.java
1
import
java.awt.Graphics;
2
import
java.awt.Graphics2D;
3
import
java.awt.Rectangle;
4
import
javax.swing.JApplet;
5
