Java Examples in a Nutshell, 3rd Edition

Filling Shapes with Paint

We’ve just seen that line drawing in Java 2D is defined in terms of the more fundamental operation of area filling. In previous examples, we’ve used the fill( ) method of Graphics2D to fill the interior of a Shape with whatever solid color was previously passed to the setColor( ) method. The Java 2D API generalizes the notion of color, however, and allows you to fill an area using any implementation of the Paint interface. The Paint implementation is responsible for specifying the colors to use in the area-filling (or line-drawing) operation. In Java 1.2 and later, the Color class implements the Paint method, allowing shapes to be filled with solid colors. Java 2D also defines two other Paint implementations: GradientPaint, which fills a shape with a color gradient, and TexturePaint, which fills a shape by tiling an image. These classes can be used to achieve some of the fill effects shown in Figure 12-8.

Figure 12-8. Filling shapes with Paint objects

Example 12-10 shows the code that generates Figure 12-8. In addition to using the GradientPaint and TexturePaint classes, this example demonstrates a variety of other Java 2D capabilities: translucent colors, font glyphs as Shape objects that create “text art,” an AffineTransform and a translucent color that produce a shadow effect, and a BufferedImage that performs off-screen drawing. Example ...