Java AWT Reference

2

Simple Graphics

In this chapter:

• Graphics
• Point
• Dimension
• Shape
• Rectangle
• Polygon
• Image
• MediaTracker

This chapter digs into the meat of the AWT classes. After completing this chapter, you will be able to draw strings, images, and shapes via the Graphics class in your Java programs. We discuss geometry-related classes—Polygon, Rectangle, Point, and Dimension, and the Shape interface—you will see these throughout the remaining AWT objects. You will also learn several ways to do smooth animation by using double buffering and the MediaTracker.

After reading this chapter, you should be able to do simple animation and image manipulation with AWT. For most applications, this should be sufficient. If you want to look at AWT's more advanced graphics capabilities, be sure to take a look at Chapter 12, Image Processing.

2.1 Graphics

The Graphics class is an abstract class that provides the means to access different graphics devices. It is the class that lets you draw on the screen, display images, and so forth. Graphics is an abstract class because working with graphics requires detailed knowledge of the platform on which the program runs. The actual work is done by concrete classes that are closely tied to a particular platform. Your Java Virtual Machine vendor provides the necessary concrete classes for your environment. You never need to worry about the platform-specific classes; once you have a Graphics object, you can call all the methods of the Graphics class, confident that the ...