source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/Style.java@ 25584

/*
 * 08/06/2004
 *
 * Style.java - A set of traits for a particular token type to use while
 * painting.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rsyntaxtextarea;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import javax.swing.JPanel;


/**
 * The color and style information for a token type.  Each token type in an
 * <code>RSyntaxTextArea</code> has a corresponding <code>Style</code>; this
 * <code>Style</code> tells us the following things:
 *
 * <ul>
 *   <li>What foreground color to use for tokens of this type.</li>
 *   <li>What background color to use.</li>
 *   <li>The font to use.</li>
 *   <li>Whether the token should be underlined.</li>
 * </ul>
 *
 * @author Robert Futrell
 * @version 0.6
 */
public class Style implements Cloneable {

    public static final Color DEFAULT_FOREGROUND    = Color.BLACK;
    public static final Color DEFAULT_BACKGROUND    = null;
    public static final Font DEFAULT_FONT           = null;

    public Color foreground;
    public Color background;
    public boolean underline;
    public Font font;

    FontMetrics fontMetrics;


    /**
     * Creates a new style defaulting to black foreground, no
     * background, and no styling.
     */
    public Style() {
        this(DEFAULT_FOREGROUND);
    }


    /**
     * Creates a new style with the specified foreground and no styling.
     *
     * @param fg The foreground color to use.
     */
    public Style(Color fg) {
        this(fg, DEFAULT_BACKGROUND);
    }


    /**
     * Creates a new style with the specified colors and no styling.
     *
     * @param fg The foreground color to use.
     * @param bg The background color to use.
     */
    public Style(Color fg, Color bg) {
        this(fg, bg, DEFAULT_FONT);
    }


    /**
     * Creates a new style.
     *
     * @param fg The foreground color to use.
     * @param bg The background color to use.
     * @param font The font for this syntax scheme.
     */
    public Style(Color fg, Color bg, Font font) {
        this(fg, bg, font, false);
    }


    /**
     * Creates a new style.
     *
     * @param fg The foreground color to use.
     * @param bg The background color to use.
     * @param font The font for this syntax scheme.
     * @param underline Whether or not to underline tokens with this style.
     */
    public Style(Color fg, Color bg, Font font, boolean underline) {
        foreground = fg;
        background = bg;
        this.font = font;
        this.underline = underline;
        this.fontMetrics = font==null ? null :
            new JPanel().getFontMetrics(font); // Default, no rendering hints!
    }


    /**
     * Returns whether or not two (possibly <code>null</code>) objects are
     * equal.
     */
    private boolean areEqual(Object o1, Object o2) {
        return (o1==null && o2==null) || (o1!=null && o1.equals(o2));
    }


    /**
     * Returns a deep copy of this object.
     *
     * @return The copy.
     */
    public Object clone() {
        Style clone = null;
        try {
            clone = (Style)super.clone();
        } catch (CloneNotSupportedException cnse) { // Never happens
            cnse.printStackTrace();
            return null;
        }
        clone.foreground = foreground;
        clone.background = background;
        clone.font = font;
        clone.underline = underline;
        clone.fontMetrics = fontMetrics;
        return clone;
    }


    /**
     * Returns whether or not two syntax schemes are equal.
     *
     * @param o2 The object with which to compare this syntax scheme.
     * @return Whether or not these two syntax schemes represent the same
     *         scheme.
     */
    public boolean equals(Object o2) {
        if (o2 instanceof Style) {
            Style ss2 = (Style)o2;
            if (this.underline==ss2.underline &&
                areEqual(foreground, ss2.foreground) &&
                areEqual(background, ss2.background) &&
                areEqual(font, ss2.font) &&
                areEqual(fontMetrics, ss2.fontMetrics))
                    return true;
        }
        return false;
    }


    /**
     * Computes the hash code to use when adding this syntax scheme to
     * hash tables.<p>
     *
     * This method is implemented, since {@link #equals(Object)} is implemented,
     * to keep FindBugs happy.
     *
     * @return The hash code.
     */
    public int hashCode() {
        int hashCode = underline ? 1 : 0;
        if (foreground!=null) {
            hashCode ^= foreground.hashCode();
        }
        if (background!=null) {
            hashCode ^= background.hashCode();
        } 
        return hashCode;
    }


    /**
     * Returns a string representation of this style.
     *
     * @return A string representation of this style.
     */
    public String toString() {
        return "[Style: foreground: " + foreground +
              ", background: " + background + ", underline: " +
              underline + ", font: " + font + "]";
    }


}