bidiline.java

一个java操作pdf文件的开发包,很好用的.

/*
 *
 * Copyright 2002 Paulo Soares
 *
 * 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.pdf;

import java.util.ArrayList;
import java.awt.font.TextLayout;
import java.text.AttributedString;
import java.awt.font.TextAttribute;
import java.awt.font.FontRenderContext;
import java.awt.geom.AffineTransform;
import java.util.HashMap;
import com.lowagie.text.*;
import java.io.*;

/** Does all the line bidirectional processing with PdfChunk assembly.
 *
 * @author Paulo Soares ([e-mail])
 */
public class BidiLine {
    
    protected int runDirection;
    protected int pieceSize = 2048;
    protected char text[] = new char[pieceSize];
    protected PdfChunk detailChunks[] = new PdfChunk[pieceSize];
    protected int totalTextLength = 0;
    
    protected byte orderLevels[] = new byte[pieceSize];
    protected int indexChars[] = new int[pieceSize];
    
    protected ArrayList chunks = new ArrayList();
    protected int indexChunk = 0;
    protected int indexChunkChar = 0;
    protected int currentChar = 0;
    
    protected int storedRunDirection;
    protected char storedText[] = new char[0];
    protected PdfChunk storedDetailChunks[] = new PdfChunk[0];
    protected int storedTotalTextLength = 0;
    
    protected byte storedOrderLevels[] = new byte[0];
    protected int storedIndexChars[] = new int[0];
    
    protected int storedIndexChunk = 0;
    protected int storedIndexChunkChar = 0;
    protected int storedCurrentChar = 0;
    
    protected boolean shortStore;
    protected ArabicShaping arabic = new ArabicShaping(ArabicShaping.LETTERS_SHAPE | ArabicShaping.LENGTH_GROW_SHRINK | ArabicShaping.TEXT_DIRECTION_LOGICAL);
    protected static final IntHashtable mirrorChars = new IntHashtable();

    /** Creates new BidiLine */
    public BidiLine() {
    }
    
    public boolean isEmpty() {
        return (currentChar >= totalTextLength && indexChunk >= chunks.size());
    }
    
    public void clearChunks() {
        chunks.clear();
        totalTextLength = 0;
        currentChar = 0;
    }

    public boolean getParagraph(int runDirection) {
        this.runDirection = runDirection;
        currentChar = 0;
        totalTextLength = 0;
        boolean hasText = false;
        char c;
        for (; indexChunk < chunks.size(); ++indexChunk) {
            PdfChunk ck = (PdfChunk)chunks.get(indexChunk);
            String s = ck.toString();
            int len = s.length();
            for (; indexChunkChar < len; ++indexChunkChar) {
                c = s.charAt(indexChunkChar);
                if (c == '\r' || c == '\n') {
                    if (c == '\r' && indexChunkChar + 1 < len && s.charAt(indexChunkChar + 1) == '\n')
                        ++indexChunkChar;
                    ++indexChunkChar;
                    if (indexChunkChar >= len) {
                        indexChunkChar = 0;
                        ++indexChunk;
                    }
                    hasText = true;
                    if (totalTextLength == 0)
                        detailChunks[0] = ck;
                    break;
                }
                addPiece(c, ck);
            }
            if (hasText)
                break;
            indexChunkChar = 0;
        }
        if (totalTextLength == 0)
            return hasText;

        // remove trailing WS
        totalTextLength = trimRight(0, totalTextLength - 1) + 1;
        if (totalTextLength == 0)
            return true;
        
        if (runDirection == PdfWriter.RUN_DIRECTION_LTR || runDirection == PdfWriter.RUN_DIRECTION_RTL) {
            if (orderLevels.length < totalTextLength) {
                orderLevels = new byte[pieceSize];
                indexChars = new int[pieceSize];
            }

            HashMap attr = new HashMap();
            if (runDirection == PdfWriter.RUN_DIRECTION_LTR)
                attr.put(TextAttribute.RUN_DIRECTION, TextAttribute.RUN_DIRECTION_LTR);
            else
                attr.put(TextAttribute.RUN_DIRECTION, TextAttribute.RUN_DIRECTION_RTL);
            
            TextLayout t = new TextLayout(new String(text, 0, totalTextLength), attr, new FontRenderContext(new AffineTransform(), false, true));
            for (int k = 0; k < totalTextLength; ++k) {
                orderLevels[k] = t.getCharacterLevel(k);
                indexChars[k] = k;
            }
            doArabicShapping();
            mirrorGlyphs();
        }
        totalTextLength = trimRightEx(0, totalTextLength - 1) + 1;
        return true;
    }
    
    public void addChunk(PdfChunk chunk) {
        chunks.add(chunk);
    }
    
    public void addChunks(ArrayList chunks) {
        this.chunks.addAll(chunks);
    }
    
    public void addPiece(char c, PdfChunk chunk) {
        if (totalTextLength >= pieceSize) {
            char tempText[] = text;
            PdfChunk tempDetailChunks[] = detailChunks;
            pieceSize *= 2;
            text = new char[pieceSize];
            detailChunks = new PdfChunk[pieceSize];
            System.arraycopy(tempText, 0, text, 0, totalTextLength);
            System.arraycopy(tempDetailChunks, 0, detailChunks, 0, totalTextLength);
        }
        text[totalTextLength] = c;
        detailChunks[totalTextLength++] = chunk;
    }
    
    public void save() {
        if (indexChunk > 0) {
            if (indexChunk >= chunks.size())
                chunks.clear();
            else {
                for (--indexChunk; indexChunk >= 0; --indexChunk)
                    chunks.remove(indexChunk);
            }
            indexChunk = 0;
        }
        storedRunDirection = runDirection;
        storedTotalTextLength = totalTextLength;
        storedIndexChunk = indexChunk;
        storedIndexChunkChar = indexChunkChar;
        storedCurrentChar = currentChar;
        shortStore = (currentChar < totalTextLength);
        if (!shortStore) {
            // long save
            if (storedText.length < totalTextLength) {
                storedText = new char[totalTextLength];
                storedDetailChunks = new PdfChunk[totalTextLength];
            }
            System.arraycopy(text, 0, storedText, 0, totalTextLength);
            System.arraycopy(detailChunks, 0, storedDetailChunks, 0, totalTextLength);
        }
        if (runDirection == PdfWriter.RUN_DIRECTION_LTR || runDirection == PdfWriter.RUN_DIRECTION_RTL) {
            if (storedOrderLevels.length < totalTextLength) {
                storedOrderLevels = new byte[totalTextLength];
                storedIndexChars = new int[totalTextLength];
            }
            System.arraycopy(orderLevels, currentChar, storedOrderLevels, currentChar, totalTextLength - currentChar);
            System.arraycopy(indexChars, currentChar, storedIndexChars, currentChar, totalTextLength - currentChar);
        }
    }
    
    public void restore() {
        runDirection = storedRunDirection;
        totalTextLength = storedTotalTextLength;
        indexChunk = storedIndexChunk;
        indexChunkChar = storedIndexChunkChar;
        currentChar = storedCurrentChar;
        if (!shortStore) {
            // long restore
            System.arraycopy(storedText, 0, text, 0, totalTextLength);
            System.arraycopy(storedDetailChunks, 0, detailChunks, 0, totalTextLength);
        }
        if (runDirection == PdfWriter.RUN_DIRECTION_LTR || runDirection == PdfWriter.RUN_DIRECTION_RTL) {
            System.arraycopy(storedOrderLevels, currentChar, orderLevels, currentChar, totalTextLength - currentChar);
            System.arraycopy(storedIndexChars, currentChar, indexChars, currentChar, totalTextLength - currentChar);
        }
    }
    
    public void mirrorGlyphs() {
        for (int k = 0; k < totalTextLength; ++k) {
            if ((orderLevels[k] & 1) == 1) {
                int mirror = mirrorChars.get(text[k]);
                if (mirror != 0)
                    text[k] = (char)mirror;
            }
        }
    }
    
    public void doArabicShapping() {
        int src = 0;
        int dest = 0;
        for (;;) {
            while (src < totalTextLength) {
                char c = text[src];
                if (c >= 0x0600 && c <= 0x06ff)
                    break;
                if (src != dest) {
                    text[dest] = text[src];
                    detailChunks[dest] = detailChunks[src];
                    orderLevels[dest] = orderLevels[src];
                }
                ++src;
                ++dest;
            }
            if (src >= totalTextLength) {
                totalTextLength = dest;
                return;
            }
            int startArabicIdx = src;
            ++src;
            while (src < totalTextLength) {