columntext.java

一个java操作pdf文件的开发包,很好用的.

/*
 * $Id: ColumnText.java,v 1.28 2002/11/19 08:33:35 blowagie Exp $
 * $Name:  $
 *
 * Copyright 2001, 2002 by 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.util.Iterator;
import com.lowagie.text.Phrase;
import com.lowagie.text.Chunk;
import com.lowagie.text.Element;
import com.lowagie.text.DocumentException;

/**
 * Formats text in a columnwise form. The text is bound
 * on the left and on the right by a sequence of lines. This allows the column
 * to have any shape, not only rectangular.
 * <P>
 * Several parameters can be set like the first paragraph line indent and
 * extra space between paragraphs.
 * <P>
 * A call to the method <CODE>go</CODE> will return one of the following
 * situations: the column ended or the text ended.
 * <P>
 * I the column ended, a new column definition can be loaded with the method
 * <CODE>setColumns</CODE> and the method <CODE>go</CODE> can be called again.
 * <P>
 * If the text ended, more text can be loaded with <CODE>addText</CODE>
 * and the method <CODE>go</CODE> can be called again.<BR>
 * The only limitation is that one or more complete paragraphs must be loaded
 * each time.
 * <P>
 * Full bidirectional reordering is supported. If the run direction is
 * <CODE>PdfWriter.RUN_DIRECTION_RTL</CODE> the meaning of the horizontal
 * alignments and margins is mirrored.
 * @author Paulo Soares ([e-mail])
 */

public class ColumnText {
    
    protected int runDirection = PdfWriter.RUN_DIRECTION_DEFAULT;
    public static final float GLOBAL_SPACE_CHAR_RATIO = 0;
    
    /** Signals that there is no more text available. */
    public static final int NO_MORE_TEXT = 1;
    
    /** Signals that there is no more column. */
    public static final int NO_MORE_COLUMN = 2;
    
    /** The column is valid. */
    protected static final int LINE_STATUS_OK = 0;
    
    /** The line is out the column limits. */
    protected static final int LINE_STATUS_OFFLIMITS = 1;
    
    /** The line cannot fit this column position. */
    protected static final int LINE_STATUS_NOLINE = 2;
    
    /** Upper bound of the column. */
    protected float maxY;
    
    /** Lower bound of the column. */
    protected float minY;
    
    /** The column alignment. Default is left alignment. */
    protected int alignment = Element.ALIGN_LEFT;
    
    /** The left column bound. */
    protected ArrayList leftWall;
    
    /** The right column bound. */
    protected ArrayList rightWall;
    
    /** The chunks that form the text. */
//    protected ArrayList chunks = new ArrayList();
    protected BidiLine bidiLine = new BidiLine();
    
    /** The current y line location. Text will be written at this line minus the leading. */
    protected float yLine;
    
    /** The leading for the current line. */
    protected float currentLeading = 16;
    
    /** The fixed text leading. */
    protected float fixedLeading = 16;
    
    /** The text leading that is multiplied by the biggest font size in the line. */
    protected float multipliedLeading = 0;
    
    /** The <CODE>PdfContent</CODE> where the text will be written to. */
    protected PdfContentByte canvas;
    
    /** The line status when trying to fit a line to a column. */
    protected int lineStatus;
    
    /** The first paragraph line indent. */
    protected float indent = 0;
    
    /** The following paragraph lines indent. */
    protected float followingIndent = 0;
    
    /** The right paragraph lines indent. */
    protected float rightIndent = 0;
    
    /** The extra space between paragraphs. */
    protected float extraParagraphSpace = 0;
    
    /** Marks the chunks to be eliminated when the line is written. */
    protected int currentChunkMarker = -1;
    
    /** The chunk created by the splitting. */
    protected PdfChunk currentStandbyChunk;
    
    /** The chunk created by the splitting. */
    protected String splittedChunkText;
    
    /** The width of the line when the column is defined as a simple rectangle. */
    protected float rectangularWidth = -1;
    
    /** Holds value of property spaceCharRatio. */
    private float spaceCharRatio = GLOBAL_SPACE_CHAR_RATIO;

    private boolean lastWasNewline = true;
    /**
     * Creates a <CODE>ColumnText</CODE>.
     * @param canvas the place where the text will be written to. Can
     * be a template.
     */
    public ColumnText(PdfContentByte canvas) {
        this.canvas = canvas;
    }
    
    /**
     * Adds a <CODE>Phrase</CODE> to the current text array.
     * @param phrase the text
     */
    public void addText(Phrase phrase) {
        for (Iterator j = phrase.getChunks().iterator(); j.hasNext();) {
            bidiLine.addChunk(new PdfChunk((Chunk)j.next(), null));
        }
    }
    
    /**
     * Adds a <CODE>Chunk</CODE> to the current text array.
     * @param chunk the text
     */
    public void addText(Chunk chunk) {
        bidiLine.addChunk(new PdfChunk(chunk, null));
    }
    
    /**
     * Converts a sequence of lines representing one of the column bounds into
     * an internal format.
     * <p>
     * Each array element will contain a <CODE>float[4]</CODE> representing
     * the line x = ax + b.
     * @param cLine the column array
     * @return the converted array
     */
    protected ArrayList convertColumn(float cLine[]) {
        if (cLine.length < 4)
            throw new RuntimeException("No valid column line found.");
        ArrayList cc = new ArrayList();
        for (int k = 0; k < cLine.length - 2; k += 2) {
            float x1 = cLine[k];
            float y1 = cLine[k + 1];
            float x2 = cLine[k + 2];
            float y2 = cLine[k + 3];
            if (y1 == y2)
                continue;
            // x = ay + b
            float a = (x1 - x2) / (y1 - y2);
            float b = x1 - a * y1;
            float r[] = new float[4];
            r[0] = Math.min(y1, y2);
            r[1] = Math.max(y1, y2);
            r[2] = a;
            r[3] = b;
            cc.add(r);
            maxY = Math.max(maxY, r[1]);
            minY = Math.min(minY, r[0]);
        }
        if (cc.size() == 0)
            throw new RuntimeException("No valid column line found.");
        return cc;
    }
    
    /**
     * Finds the intersection between the <CODE>yLine</CODE> and the column. It will
     * set the <CODE>lineStatus</CODE> apropriatly.
     * @param wall the column to intersect
     * @return the x coordinate of the intersection
     */
    protected float findLimitsPoint(ArrayList wall) {
        lineStatus = LINE_STATUS_OK;
        if (yLine < minY || yLine > maxY) {
            lineStatus = LINE_STATUS_OFFLIMITS;
            return 0;
        }
        for (int k = 0; k < wall.size(); ++k) {
            float r[] = (float[])wall.get(k);
            if (yLine < r[0] || yLine > r[1])
                continue;
            return r[2] * yLine + r[3];
        }
        lineStatus = LINE_STATUS_NOLINE;
        return 0;
    }
    
    /**
     * Finds the intersection between the <CODE>yLine</CODE> and the two
     * column bounds. It will set the <CODE>lineStatus</CODE> apropriatly.
     * @return a <CODE>float[2]</CODE>with the x coordinates of the intersection
     */
    protected float[] findLimitsOneLine() {
        for (;;) {
            float x1 = findLimitsPoint(leftWall);
            if (lineStatus == LINE_STATUS_OFFLIMITS || lineStatus == LINE_STATUS_NOLINE)
                return null;
            float x2 = findLimitsPoint(rightWall);
            if (lineStatus == LINE_STATUS_NOLINE)
                return null;
            return new float[]{x1, x2};
        }
    }
    
    /**
     * Finds the intersection between the <CODE>yLine</CODE>,
     * the <CODE>yLine-leading</CODE>and the two
     * column bounds. It will set the <CODE>lineStatus</CODE> apropriatly.
     * @return a <CODE>float[4]</CODE>with the x coordinates of the intersection
     */
    protected float[] findLimitsTwoLines() {
        for (;;) {
            float x1[] = findLimitsOneLine();
            if (lineStatus == LINE_STATUS_OFFLIMITS)
                return null;
            yLine -= currentLeading;
            if (lineStatus == LINE_STATUS_NOLINE) {
                continue;
            }
            float x2[] = findLimitsOneLine();
            if (lineStatus == LINE_STATUS_OFFLIMITS)
                return null;
            if (lineStatus == LINE_STATUS_NOLINE) {
                yLine -= currentLeading;
                continue;
            }
            if (x1[0] >= x2[1] || x2[0] >= x1[1])
                continue;
            return new float[]{x1[0], x1[1], x2[0], x2[1]};
        }
    }
    
    /**
     * Sets the columns bounds. Each column bound is described by a
     * <CODE>float[]</CODE> with the line points [x1,y1,x2,y2,...].
     * The array must have at least 4 elements.
     * @param leftLine the left column bound
     * @param rightLine the right column bound
     */
    public void setColumns(float leftLine[], float rightLine[]) {
        rightWall = convertColumn(rightLine);
        leftWall = convertColumn(leftLine);
        rectangularWidth = -1;
    }
    
    /**
     * Simplified method for rectangular columns.
     * @param phrase a <CODE>Phrase</CODE>
     * @param llx the lower left x corner
     * @param lly the lower left y corner
     * @param urx the upper right x corner
     * @param ury the upper right y corner
     * @param leading the leading
     * @param alignment the column alignment
     */
    public void setSimpleColumn(Phrase phrase, float llx, float lly, float urx, float ury, float leading, int alignment) {
        addText(phrase);
        setSimpleColumn(llx, lly, urx, ury, leading, alignment);
    }
    
    /**
     * Simplified method for rectangular columns.
     * @param llx the lower left x corner
     * @param lly the lower left y corner
     * @param urx the upper right x corner
     * @param ury the upper right y corner
     * @param leading the leading
     * @param alignment the column alignment
     */