using System;
using System.Collections;

/*
 * Copyright 1999, 2000, 2001, 2002 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/
 */

namespace iTextSharp.text.pdf {

    /**
    * <CODE>PdfTextArray</CODE> defines an array with displacements and <CODE>PdfString</CODE>-objects.
    * <P>
    * A <CODE>TextArray</CODE> is used with the operator <VAR>TJ</VAR> in <CODE>PdfText</CODE>.
    * The first object in this array has to be a <CODE>PdfString</CODE>;
    * see reference manual version 1.3 section 8.7.5, pages 346-347.
    *       OR
    * see reference manual version 1.6 section 5.3.2, pages 378-379.
    */

    public class PdfTextArray{
        ArrayList arrayList = new ArrayList();
        
        // To emit a more efficient array, we consolidate
        // repeated numbers or strings into single array entries.
        // "add( 50 ); Add( -50 );" will REMOVE the combined zero from the array.
        // the alternative (leaving a zero in there) was Just Weird.
        // --Mark Storer, May 12, 2008
        private String lastStr;
        private float lastNum = float.NaN;
        
        // constructors
        public PdfTextArray(String str) {
            Add(str);
        }
        
        public PdfTextArray() {
        }
        
        /**
        * Adds a <CODE>PdfNumber</CODE> to the <CODE>PdfArray</CODE>.
        *
        * @param  number   displacement of the string
        */
        public void Add(PdfNumber number) {
            Add((float)number.DoubleValue);
        }
        
        public void Add(float number) {
            if (number != 0) {
                if (!float.IsNaN(lastNum)) {
                    lastNum += number;
                    if (lastNum != 0) {
                        ReplaceLast(lastNum);
                    } else {
                        arrayList.RemoveAt(arrayList.Count - 1);
                    }
                } else {
                    lastNum = number;
                    arrayList.Add(lastNum);
                }
                lastStr = null;
            }
            // adding zero doesn't modify the TextArray at all
        }
        
        public void Add(String str) {
            if (str.Length > 0) {
                if (lastStr != null) {
                    lastStr = lastStr + str;
                    ReplaceLast(lastStr);
                } else {
                    lastStr = str;
                    arrayList.Add(lastStr);
                }
                lastNum = float.NaN;
            }
            // adding an empty string doesn't modify the TextArray at all
        }
        
        internal ArrayList ArrayList {
            get {
                return arrayList;
            }
        }
        
        private void ReplaceLast(Object obj) {
            // deliberately throw the IndexOutOfBoundsException if we screw up.
            arrayList[arrayList.Count - 1] = obj;
        }
    }
}