Learning Java - Chapter 6 : Basics

SimpleDraw1Applet.java

import java.applet.Applet;
import java.awt.Graphics;

/** Demonstrate basic AWT drawing with Graphics. **/
public class SimpleDraw1Applet extends Applet
{
  public void paint (Graphics g) {
   // Get the drawing area
   int dY = getSize ().height;
   int dX = getSize ().width;
   int midY = dY/2;
   int midX =d X/2;

   // Set current drawing color
   g.setColor (Color.red);
   // Draw a rectangle centered at the mid-point
   g.drawRect (midX-22,midY-22,44,44);
   // Set a new drawing color
   g.setColor (Color.green);
   // Fill a rectangle centered at the mid-point
   // Put it within the previous rectangle so that
   // border shows.
   g.fillRect (midX-21,midY-21,42,42);
   // Set a new drawing color
   g.setColor (Color.blue);
   // Draw a circle around the mid-point
   g.drawOval (midX-20,midY-21,40,40);
  } // paint
} // SimpleDraw1Applet

Note how we obtained the dimensions of the drawing area. The getSize() method returns an instance of the Dimension class, which provides direct access to its height and width variables. (As of Java 1.2, component includes the methods getHeight() and getWidth().)