Java 2D Graphics Attributes and Operations (Java Foundation Classes)

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4.2. Java 2D Graphics Attributes and Operations

Java 2D dramatically expands the graphics capabilities of Java. It does this through the java.awt.Graphics2D subclass of java.awt.Graphics. In Java 2, you can simply cast any Graphics object you are given to a Graphics2D object, and then you can use the new features of Java 2D.

Table 4-5 and Table 4-6 summarize the new features of Java 2D by listing the graphics attributes and graphics operations supported by the Graphics2D class.

Table 4-5. Graphics Attributes of Java 2D

Attribute	Type	Description
Foreground color	`Color`	Inherited from `Graphics` but superseded by the fill style attribute and the `Paint` interface.
Background color	`Color`	Inherited from `Graphics` but can now be set and queried with `setBack- ground()` and `getBackground()`. This attribute is still used only by `clearRect()`.
Font	`Font`	Inherited from `Graphics`. All of the system fonts are now available to Java.
Clipping region	`Shape`	Inherited from `Graphics`. In Java 2D, however, arbitrary `Shape` objects may be used; the clipping region is no longer restricted to only rectangular shapes. A new method, which is called `clip()`, sets the clipping region to the intersection of the current region and a specified `Shape`.
Line style	`Stroke`	A `Stroke` object specifies how lines are drawn. The `BasicStroke` implementation supports line width, dash pattern, and other attributes, described in more detail later in the chapter. Set the current line style with `setStroke()`.
Fill style	`Paint`	A `Paint` object specifies how an area is filled. `Color` implements this interface and fills with a solid color, `java.awt.TexturePaint` fills with a tiled image, and `java.awt.Gra- dientPaint` fills with a color gradient. Set the current fill style with `setPaint()`.
Compositing	`Composite`	A `Composite` object controls how the color of a pixel is combined, or composited, with the color of the pixel on top of which it is drawn. The default compositing operation combines translucent pixels with the pixels they overlay, letting the overlaid colors "show through." The `AlphaComposite` class is an implementation of `Composite`; it performs various types of compositing, based on the alpha-transparency of the pixels involved.
Transform	`java.awt.geom.- AffineTransform`	Controls the translation, scaling, rotation, and shearing of the coordinate system. Set this attribute with `setTransform()`, or modify the current transform with `translate()`, `scale()`, `rotate()`, `shear()`, or `transform()`.
Hints	`RenderingHints`	A `RenderingHints` object allows a program to express preferences about various speed versus quality trade-offs made by Java 2D. Most notably, `RenderingHints` controls whether Java 2D performs antialiasing. Set with `setRenderingHints()`, `setRendering- Hint()`, or `addRenderingHints()`.

Table 4-6. Graphics Operations of Java 2D

Operation	Methods	Description
Drawing	`draw()`, inherited methods	`draw()` outlines an arbitrary `Shape`. Uses the clip, transform, stroke, paint, and composite attributes.
Filling	`fill()`, inherited methods	`fill()` fills an arbitrary `Shape`. Uses the clip, transform, paint, and composite attributes.
Hit detection	`hit()`	Tests whether a given rectangle (in device coordinates) intersects the interior or outline of an arbitrary `Shape`. Uses the clip, transform, and stroke attributes when testing the outline of a `Shape`.
Text drawing	`drawString()`, `drawGlyphVector()`, inherited methods	Java 2D defines text-drawing methods that take `String`, `java.text.AttributedCharacter- Iterator`, and `java.awt.font.- GlyphVector` arguments. Text drawing uses the clip, transform, font, paint, and composite attributes. Note, however, that `AttributedCharacterIterator` objects supply their own fonts.
Image drawing	`drawImage()`, `drawRenderableImage()`, `drawRenderedImage()`, inherited methods	Java 2D defines new image-drawing methods that draw special types of images. `java.awt.image.BufferedImage` is the most important new type. These methods use the clip, transform, and composite attributes.


4.1. Graphics Before Java 2D		4.3. The Coordinate System