/*
 * $Id$
 *
 * Copyright 1999, 2000, 2001, 2002 by Bruno Lowagie.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or 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.
 *
 * 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/
 */

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@ugent.be
 */

public final 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'] = "\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
            if (character < 256) {
                buffer.append(htmlCode[character]);
            }
            else {
                // Improvement posted by Joachim Eyrich
                buffer.append("&#").append((int)character).append(';');
            }
        }
        return buffer.toString();
    }
    
/**
 * 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:
            case Element.ALIGN_JUSTIFIED_ALL:
                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 "";
        }
    }
}