/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.text.TextAttribute;

import dwt.dwthelper.utils;


import dwt.DWT;
import dwt.graphics.Color;
import dwt.graphics.Font;


/**
 * Description of textual attributes such as color and style. Text attributes
 * are considered value objects.
 * <p>
 * Clients usually instantiate object of the class.</p>
 */
public class TextAttribute {

    /**
     * Text attribute for strikethrough style.
     * (value <code>1 << 29</code>).
     * @since 3.1
     */
    public static final int STRIKETHROUGH= 1 << 29;

    /**
     * Text attribute for underline style.
     * (value <code>1 << 30</code>)
     * @since 3.1
     */
    public static final int UNDERLINE= 1 << 30;


    /** Foreground color */
    private Color foreground;

    /** Background color */
    private Color background;

    /** The text style */
    private int style;
    
    /**
     * The text font.
     * @since 3.3
     */
    private Font font;

    /**
     * Cached hash code.
     * @since 3.3
     */
    private int fHashCode;

    /**
     * Creates a text attribute with the given colors and style.
     *
     * @param foreground the foreground color, <code>null</code> if none
     * @param background the background color, <code>null</code> if none
     * @param style the style
     */
    public TextAttribute(Color foreground, Color background, int style) {
        this.foreground= foreground;
        this.background= background;
        this.style= style;
    }
    
    /**
     * Creates a text attribute with the given colors and style.
     *
     * @param foreground the foreground color, <code>null</code> if none
     * @param background the background color, <code>null</code> if none
     * @param style the style
     * @param font the font, <code>null</code> if none
     * @since 3.3
     */
    public TextAttribute(Color foreground, Color background, int style, Font font) {
        this.foreground= foreground;
        this.background= background;
        this.style= style;
        this.font= font;
    }

    /**
     * Creates a text attribute for the given foreground color, no background color and
     * with the DWT normal style.
     *
     * @param foreground the foreground color, <code>null</code> if none
     */
    public TextAttribute(Color foreground) {
        this(foreground, null, DWT.NORMAL);
    }

    /*
     * @see Object#equals(Object)
     */
    public bool equals(Object object) {

        if (object is this)
            return true;

        if (!(object instanceof TextAttribute))
            return false;
        TextAttribute a= (TextAttribute)object;
        
        return (a.style is style && equals(a.foreground, foreground) && equals(a.background, background) && equals(a.font, font));
    }

    /**
     * Returns whether the two given objects are equal.
     *
     * @param o1 the first object, can be <code>null</code>
     * @param o2 the second object, can be <code>null</code>
     * @return <code>true</code> if the given objects are equals
     * @since 2.0
     */
    private bool equals(Object o1, Object o2) {
        if (o1 !is null)
            return o1.equals(o2);
        return (o2 is null);
    }

    /*
     * @see Object#hashCode()
     */
     public int hashCode() {
         if (fHashCode is 0) {
             int multiplier= 37; // some prime
             fHashCode= 13; // some random value
             fHashCode= multiplier * fHashCode + (font is null ? 0 : font.hashCode());
             fHashCode= multiplier * fHashCode + (background is null ? 0 : background.hashCode());
             fHashCode= multiplier * fHashCode + (foreground is null ? 0 : foreground.hashCode());
             fHashCode= multiplier * fHashCode + style;
         }
        return fHashCode;
     }

    /**
     * Returns the attribute's foreground color.
     *
     * @return the attribute's foreground color or <code>null</code> if not set
     */
    public Color getForeground() {
        return foreground;
    }

    /**
     * Returns the attribute's background color.
     *
     * @return the attribute's background color or <code>null</code> if not set
     */
    public Color getBackground() {
        return background;
    }

    /**
     * Returns the attribute's style.
     *
     * @return the attribute's style
     */
    public int getStyle() {
        return style;
    }
    
    /**
     * Returns the attribute's font.
     *
     * @return the attribute's font or <code>null</code> if not set
     * @since 3.3
     */
    public Font getFont() {
        return font;
    }
}