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Java graphics Graphics methods are part of the AWT. Important AWT graphics classes include:
Because a Java program may be sharing the computer screen with any number of other programs, graphics methods are directed to specific AWT components. There is not, nor should there ever be, any procedure to draw directly to the screen. This means that when specifying the position of a shape or image, we specify it relative to the component in which it is drawn. Although it is possible to draw graphics directly to a Window or Frame object, this is a bad practice. Doing this makes it difficult to re-use the graphics code in new programs (because one would have to separate out the graphics parts from the part that handles window events). The correct procedure is to create a subclass of Canvas or Panel and make it draw itself by over-riding the ‘paint’ method. In Java, as in most programming languages that support a graphical user interface, the graphics methods are volatile (you will also see the term `non-persistent' used). This means that the graphical information that is displayed on the screen will not be retained if the program's display is over-written. This happens if, for example, your program is hidden `behind' another program on the screen. When this happens, your program must be ready to re-draw its display whenever it is `raised' to the top again. Java makes this quite straightforward. Every user interface component has a method called paint(). This method is called whenever the system detects that the component needs to be re-painted. It is not the job of the programmer to manage the re-painting of the screen.
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