Java - Applet - Animation

Animation in an applet refers to the technique of displaying a series of images or frames in quick succession to create the illusion of motion. In Java applets, animation can be achieved using the Thread class and the repaint() method.

Here are the basic steps to create animation in a Java applet:

1. Create a class that extends the Applet class and implements the Runnable interface. This class will serve as the main applet class and will contain the code to draw the animation.
2. Declare and initialize a Thread object inside the init() method of the applet class. This thread will be used to update the animation periodically.
3. Override the run() method of the Runnable interface. This method should contain the code to update the animation and call the repaint() method to redraw the screen.
4. Override the paint() method of the applet class. This method should contain the code to draw the animation frame by frame.
5. Call the start() method of the thread object inside the init() method of the applet class to start the animation.

Here is an example code snippet that demonstrates how to create animation in a Java applet using the above steps:

import java.applet.*;
import java.awt.*;

public class MyAnimation extends Applet implements Runnable {

   private int x = 0;
   private int y = 50;
   private Thread thread;

   public void init() {
      thread = new Thread(this);
      thread.start();
   }

   public void run() {
      while(true) {
         x += 5;
         repaint();
         try {
            Thread.sleep(100);
         } catch(Exception e) {
            e.printStackTrace();
         }
      }
   }

   public void paint(Graphics g) {
      g.drawString("Moving text", x, y);
   }
}

This example creates an applet that displays a moving text on the screen. The run() method updates the x coordinate of the text and calls the repaint() method to redraw the screen. The paint() method draws the text at the updated x coordinate. The Thread.sleep(100) method is used to pause the animation for 100 milliseconds before updating the next frame.