/*
 * $Id: HtmlEncoder.java,v 1.12 2001/12/10 13:53:21 blowagie Exp $
 * $Name:  $
 *
 * Copyright 1999, 2000, 2001 by Bruno Lowagie.
 *
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or any
 * later version.
 *
 * This library 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 Library general Public License for more
 * details.
 *
 * You should have received a copy of the GNU Library General Public License along
 * with this library; if not, write to the Free Foundation, Inc., 59 Temple Place,
 * Suite 330, Boston, MA 02111-1307 USA.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 *
 * ir-arch Bruno Lowagie,
 * Adolf Baeyensstraat 121
 * 9040 Sint-Amandsberg
 * BELGIUM
 * tel. +32 (0)9 228.10.97
 * bruno@lowagie.com
 *
 * Very special thanks to my colleague at the University of Ghent,
 * Mario Maccarini (mario.maccarini@rug.ac.be); he made some very
 * useful HTML-classes.
 */

package com.lowagie.text.html;

import java.awt.Color;

import com.lowagie.text.Element;

/**
 * This class converts a <CODE>String</CODE> to the HTML-format of a String.
 * <P>
 * To convert the <CODE>String</CODE>, each character is examined:
 * <UL>
 * <LI>ASCII-characters from 000 till 031 are represented as &amp;#xxx;<BR>
 *     (with xxx = the value of the character)
 * <LI>ASCII-characters from 032 t/m 127 are represented by the character itself, except for:
 *     <UL>
 *     <LI>'\n'	becomes &lt;BR&gt;\n
 *     <LI>&quot; becomes &amp;quot;
 *     <LI>&amp; becomes &amp;amp;
 *     <LI>&lt; becomes &amp;lt;
 *     <LI>&gt; becomes &amp;gt;
 *     </UL>
 * <LI>ASCII-characters from 128 till 255 are represented as &amp;#xxx;<BR>
 *     (with xxx = the value of the character)
 * </UL>
 * <P>
 * Example:
 * <P><BLOCKQUOTE><PRE>
 *    String htmlPresentation = HtmlEncoder.encode("Marie-Th&#233;r&#232;se S&#248;rensen");
 * </PRE></BLOCKQUOTE><P>
 * for more info: see O'Reilly; "HTML: The Definitive Guide" (page 164)
 *
 * @author  mario.maccarini@rug.ac.be
 */

public class HtmlEncoder {
    
    // membervariables
    
/** List with the HTML translation of all the characters. */
    private static final String[] htmlCode = new String[256];
    
    static {
        for (int i = 0; i < 10; i++) {
            htmlCode[i] = "&#00" + i + ";";
        }
        
        for (int i = 10; i < 32; i++) {
            htmlCode[i] = "&#0" + i + ";";
        }
        
        for (int i = 32; i < 128; i++) {
            htmlCode[i] = String.valueOf((char)i);
        }
        
        // Special characters
        htmlCode['\t'] = "";
        htmlCode['\n'] = "<" + HtmlTags.NEWLINE + " />\n";
        htmlCode['\"'] = "&quot;"; // double quote
        htmlCode['&'] = "&amp;"; // ampersand
        htmlCode['<'] = "&lt;"; // lower than
        htmlCode['>'] = "&gt;"; // greater than
        
        for (int i = 128; i < 256; i++) {
            htmlCode[i] = "&#" + i + ";";
        }
    }
    
    
    // constructors
    
/**
 * This class will never be constructed.
 * <P>
 * HtmlEncoder only contains static methods.
 */
    
    private HtmlEncoder () { }
    
    // methods
    
/**
 * Converts a <CODE>String</CODE> to the HTML-format of this <CODE>String</CODE>.
 *
 * @param	string	The <CODE>String</CODE> to convert
 * @return	a <CODE>String</CODE>
 */
    
    public static String encode(String string) {
        int n = string.length();
        char character;
        StringBuffer buffer = new StringBuffer();
        // loop over all the characters of the String.
        for (int i = 0; i < n; i++) {
            character = string.charAt(i);
            // the Htmlcode of these characters are added to a StringBuffer one by one
            try {
                buffer.append(htmlCode[character]);
            }
            catch(ArrayIndexOutOfBoundsException aioobe) {
                buffer.append(character);
            }
        }
        return buffer.toString().trim();
    }
    
/**
 * Converts a <CODE>Color</CODE> into a HTML representation of this <CODE>Color</CODE>.
 *
 * @param	color	the <CODE>Color</CODE> that has to be converted.
 * @return	the HTML representation of this <COLOR>Color</COLOR>
 */
    
    public static String encode(Color color) {
        StringBuffer buffer = new StringBuffer("#");
        if (color.getRed() < 16) {
            buffer.append('0');
        }
        buffer.append(Integer.toString(color.getRed(), 16));
        if (color.getGreen() < 16) {
            buffer.append('0');
        }
        buffer.append(Integer.toString(color.getGreen(), 16));
        if (color.getBlue() < 16) {
            buffer.append('0');
        }
        buffer.append(Integer.toString(color.getBlue(), 16));
        return buffer.toString();
    }
    
/**
 * Translates the alignment value.
 *
 * @param   alignment   the alignment value
 * @return  the translated value
 */
    
    public static String getAlignment(int alignment) {
        switch(alignment) {
            case Element.ALIGN_LEFT:
                return HtmlTags.ALIGN_LEFT;
            case Element.ALIGN_CENTER:
                return HtmlTags.ALIGN_CENTER;
            case Element.ALIGN_RIGHT:
                return HtmlTags.ALIGN_RIGHT;
            case Element.ALIGN_JUSTIFIED:
                return HtmlTags.ALIGN_JUSTIFIED;
            case Element.ALIGN_TOP:
                return HtmlTags.ALIGN_TOP;
            case Element.ALIGN_MIDDLE:
                return HtmlTags.ALIGN_MIDDLE;
            case Element.ALIGN_BOTTOM:
                return HtmlTags.ALIGN_BOTTOM;
            case Element.ALIGN_BASELINE:
                return HtmlTags.ALIGN_BASELINE;
                default:
                    return "";
        }
    }
}