ColorType.java

/*
 * Copyright 2002-2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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 */
package javax.swing.plaf.synth;

/**
 * A typesafe enumeration of colors that can be fetched from a style.
 * <p>
 * Each <code>SynthStyle</code> has a set of <code>ColorType</code>s that
 * are accessed by way of the
 * {@link SynthStyle#getColor(SynthContext, ColorType)} method.
 * <code>SynthStyle</code>'s <code>installDefaults</code> will install
 * the <code>FOREGROUND</code> color
 * as the foreground of
 * the Component, and the <code>BACKGROUND</code> color to the background of
 * the component (assuming that you have not explicitly specified a
 * foreground and background color). Some components
 * support more color based properties, for
 * example <code>JList</code> has the property
 * <code>selectionForeground</code> which will be mapped to
 * <code>FOREGROUND</code> with a component state of
 * <code>SynthConstants.SELECTED</code>.
 * <p>
 * The following example shows a custom <code>SynthStyle</code> that returns
 * a red Color for the <code>DISABLED</code> state, otherwise a black color.
 * <pre>
 * class MyStyle extends SynthStyle {
 *     private Color disabledColor = new ColorUIResource(Color.RED);
 *     private Color color = new ColorUIResource(Color.BLACK);
 *     protected Color getColorForState(SynthContext context, ColorType type){
 *         if (context.getComponentState() == SynthConstants.DISABLED) {
 *             return disabledColor;
 *         }
 *         return color;
 *     }
 * }
 * </pre>
 *
 * @since 1.5
 * @author Scott Violet
 */
public class ColorType {
    /**
     * ColorType for the foreground of a region.
     */
    public static final ColorType FOREGROUND = new ColorType("Foreground");

    /**
     * ColorType for the background of a region.
     */
    public static final ColorType BACKGROUND = new ColorType("Background");

    /**
     * ColorType for the foreground of a region.
     */
    public static final ColorType TEXT_FOREGROUND = new ColorType(
                                       "TextForeground");

    /**
     * ColorType for the background of a region.
     */
    public static final ColorType TEXT_BACKGROUND =new ColorType(
                                       "TextBackground");

    /**
     * ColorType for the focus.
     */
    public static final ColorType FOCUS = new ColorType("Focus");

    /**
     * Maximum number of <code>ColorType</code>s.
     */
    public static final int MAX_COUNT;

    private static int nextID;

    private String description;
    private int index;

    static {
        MAX_COUNT = Math.max(FOREGROUND.getID(), Math.max(
                                 BACKGROUND.getID(), FOCUS.getID())) + 1;
    }

    /**
     * Creates a new ColorType with the specified description.
     *
     * @param description String description of the ColorType.
     */
    protected ColorType(String description) {
        if (description == null) {
            throw new NullPointerException(
                          "ColorType must have a valid description");
        }
        this.description = description;
        synchronized(ColorType.class) {
            this.index = nextID++;
        }
    }

    /**
     * Returns a unique id, as an integer, for this ColorType.
     *
     * @return a unique id, as an integer, for this ColorType.
     */
    public final int getID() {
        return index;
    }

    /**
     * Returns the textual description of this <code>ColorType</code>.
     * This is the same value that the <code>ColorType</code> was created
     * with.
     *
     * @return the description of the string
     */
    public String toString() {
        return description;
    }
}