Java Swing

Image Utilities

The last category of utility classes to look at is image utilities. The Swing package contains a class that can come in handy for generating images.

The GrayFilter Class

The GrayFilter class is an extension of the java.awt.image.RGBImageFilter class. This class contains a static method that returns a “disabled” version of an image passed in. The image is converted to a grayscale version, and some lighter parts of the image are amplified to ensure the image is recognizable. All of the components that can display images use this class to present a default disabled version of the image if an explicit disabled image was not provided.

Constructors

public GrayFilter(boolean brighter, int percent)

Creates an instance of the GrayFilter class that you can use to do your own filtering. (Normally you don’t call this, but use createDisabledImage() instead.) Both the brighter and percent arguments are used to convert color pixels to appropriately shaded gray pixels.

Image Methods

public static Image createDisabledImage(Image i)

Use this method to retrieve a grayed-out version of the image i. This method creates an instance of the GrayFilter class with brighter turned on and a gray percent of 50.

public int filterRGB(int x, int y, int rgb)

Overrides the filterRGB() method in RGBImageFilter, converts the rgb pixel to a gray pixel, and returns that.

The Renderer Interface

The Swing package includes a Renderer interface with the following methods:

public Component getComponent()

Returns ...