Java AWT Reference

15

Toolkit and Peers

In this chapter:

• Toolkit
• The Peer Interfaces

This chapter describes the Toolkit class and the purposes it serves. It also describes the java.awt.peer package of interfaces, along with how they fit in with the general scheme of things. The most important advice I can give you about the peer interfaces is not to worry about them. Unless you are porting Java to another platform, creating your own Toolkit, or adding any native component, you can ignore the peer interfaces.

15.1 Toolkit

The Toolkit object is an abstract class that provides an interface to platform-specific details like window size, available fonts, and printing. Every platform that supports Java must provide a concrete class that extends the Toolkit class. The Sun JDK provides a Toolkit for Windows NT/95 (sun.awt.win32.MToolkit [Java1.0] or sun.awt.windows.MToolkit [Java1.1]), Solaris/Motif (sun.awt.motif.MToolkit), and Macintosh (sun.awt.macos.MToolkit). Although the Toolkit is used frequently, both directly and behind the scenes, you would never create any of these objects directly. When you need a Toolkit, you ask for it with the static method getDefaultToolkit() or the Component.getToolkit() method.

You might use the Toolkit object if you need to fetch an image in an application (getImage()), get the font information provided with the Toolkit (getFontList() or getFontMetrics()), get the color model (getColorModel()), get the screen metrics (getScreenResolution() or getScreenSize()), get ...