pdfcontentbyte.java

一个java操作pdf文件的开发包,很好用的.

/*
 * $Id: PdfContentByte.java,v 1.50 2002/11/19 08:33:36 blowagie Exp $
 * $Name:  $
 *
 * 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/
 */

package com.lowagie.text.pdf;
import java.awt.Color;
import com.lowagie.text.Image;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Rectangle;
import com.lowagie.text.Image;
import java.util.ArrayList;

/**
 * <CODE>PdfContentByte</CODE> is an object containing the user positioned
 * text and graphic contents of a page. It knows how to apply the proper
 * font encoding.
 */

public class PdfContentByte {
    
    /**
     * This class keeps the graphic state of the current page
     */
    
    class GraphicState {
        
        /** This is the font in use */
        FontDetails fontDetails;
        
        /** This is the color in use */
        ColorDetails colorDetails;
        
        /** This is the font size in use */
        float size;
        
        /** The x position of the text line matrix. */
        protected float xTLM = 0;
        /** The y position of the text line matrix. */
        protected float yTLM = 0;
        
        /** The current text leading. */
        protected float leading = 0;
    }
    
    /** The alignement is center */
    public static final int ALIGN_CENTER = 0;
    
    /** The alignement is left */
    public static final int ALIGN_LEFT = 1;
    
    /** The alignement is right */
    public static final int ALIGN_RIGHT = 2;
    
    // membervariables
    
    /** This is the actual content */
    protected ByteBuffer content = new ByteBuffer();
    
    /** This is the writer */
    protected PdfWriter writer;
    
    /** This is the PdfDocument */
    protected PdfDocument pdf;
    
    /** This is the GraphicState in use */
    protected GraphicState state = new GraphicState();
    
    /** The list were we save/restore the state */
    protected ArrayList stateList = new ArrayList();
    
    /** The separator between commands.
     */
    protected int separator = '\n';
    
    // constructors
    
    /**
     * Constructs a new <CODE>PdfContentByte</CODE>-object.
     *
     * @param wr the writer associated to this content
     */
    
    public PdfContentByte(PdfWriter wr) {
        if (wr != null) {
            writer = wr;
            pdf = writer.getPdfDocument();
        }
    }
    
    // methods to get the content of this object
    
    /**
     * Returns the <CODE>String</CODE> representation of this <CODE>PdfContentByte</CODE>-object.
     *
     * @return		a <CODE>String</CODE>
     */
    
    public String toString() {
        return content.toString();
    }
    
    /**
     * Gets the internal buffer.
     * @return the internal buffer
     */
    ByteBuffer getInternalBuffer() {
        return content;
    }
    
    /** Returns the PDF representation of this <CODE>PdfContentByte</CODE>-object.
     *
     * @param writer the <CODE>PdfWriter</CODE>
     * @return a <CODE>byte</CODE> array with the representation
     */
    
    public byte[] toPdf(PdfWriter writer) {
        return content.toByteArray();
    }
    
    // methods to add graphical content
    
    /**
     * Adds the content of another <CODE>PdfContent</CODE>-object to this object.
     *
     * @param		other		another <CODE>PdfByteContent</CODE>-object
     */
    
    public void add(PdfContentByte other) {
        if (other.writer != null && writer != other.writer)
            throw new RuntimeException("Inconsistent writers. Are you mixing two documents?");
        content.append(other.content);
    }
    
    /**
     * Gets the x position of the text line matrix.
     *
     * @return the x position of the text line matrix
     */
    public float getXTLM() {
        return state.xTLM;
    }
    
    /**
     * Gets the y position of the text line matrix.
     *
     * @return the y position of the text line matrix
     */
    public float getYTLM() {
        return state.yTLM;
    }
    
    /**
     * Gets the current text leading.
     *
     * @return the current text leading
     */
    public float getLeading() {
        return state.leading;
    }
    
    /**
     * Changes the <VAR>Flatness</VAR>.
     * <P>
     * <VAR>Flatness</VAR> sets the maximum permitted distance in device pixels between the
     * mathematically correct path and an approximation constructed from straight line segments.<BR>
     *
     * @param		flatness		a value
     */
    
    public void setFlatness(float flatness) {
        if (flatness >= 0 && flatness <= 100) {
            content.append(flatness).append(" i").append_i(separator);
        }
    }
    
    /**
     * Changes the <VAR>Line cap style</VAR>.
     * <P>
     * The <VAR>line cap style</VAR> specifies the shape to be used at the end of open subpaths
     * when they are stroked.<BR>
     * Allowed values are 0 (Butt end caps), 1 (Round end caps) and 2 (Projecting square end caps).<BR>
     *
     * @param		style		a value
     */
    
    public void setLineCap(int style) {
        if (style >= 0 && style <= 2) {
            content.append(style).append(" J").append_i(separator);
        }
    }
    
    /**
     * Changes the value of the <VAR>line dash pattern</VAR>.
     * <P>
     * The line dash pattern controls the pattern of dashes and gaps used to stroke paths.
     * It is specified by an <I>array</I> and a <I>phase</I>. The array specifies the length
     * of the alternating dashes and gaps. The phase specifies the distance into the dash
     * pattern to start the dash.<BR>
     *
     * @param		phase		the value of the phase
     */
    
    public void setLineDash(float phase) {
        content.append("[] ").append(phase).append(" d").append_i(separator);
    }
    
    /**
     * Changes the value of the <VAR>line dash pattern</VAR>.
     * <P>
     * The line dash pattern controls the pattern of dashes and gaps used to stroke paths.
     * It is specified by an <I>array</I> and a <I>phase</I>. The array specifies the length
     * of the alternating dashes and gaps. The phase specifies the distance into the dash
     * pattern to start the dash.<BR>
     *
     * @param		phase		the value of the phase
     * @param		unitsOn		the number of units that must be 'on' (equals the number of units that must be 'off').
     */
    
    public void setLineDash(float unitsOn, float phase) {
        content.append("[").append(unitsOn).append("] ").append(phase).append(" d").append_i(separator);
    }
    
    /**
     * Changes the value of the <VAR>line dash pattern</VAR>.
     * <P>
     * The line dash pattern controls the pattern of dashes and gaps used to stroke paths.
     * It is specified by an <I>array</I> and a <I>phase</I>. The array specifies the length
     * of the alternating dashes and gaps. The phase specifies the distance into the dash
     * pattern to start the dash.<BR>
     *
     * @param		phase		the value of the phase
     * @param		unitsOn		the number of units that must be 'on'
     * @param		unitsOff	the number of units that must be 'off'
     */
    
    public void setLineDash(float unitsOn, float unitsOff, float phase) {
        content.append("[").append(unitsOn).append(' ').append(unitsOff).append("] ").append(phase).append(" d").append_i(separator);
    }
    
    /**
     * Changes the <VAR>Line join style</VAR>.
     * <P>
     * The <VAR>line join style</VAR> specifies the shape to be used at the corners of paths
     * that are stroked.<BR>
     * Allowed values are 0 (Miter joins), 1 (Round joins) and 2 (Bevel joins).<BR>
     *
     * @param		style		a value
     */
    
    public void setLineJoin(int style) {
        if (style >= 0 && style <= 2) {
            content.append(style).append(" j").append_i(separator);
        }
    }
    
    /**
     * Changes the <VAR>line width</VAR>.
     * <P>
     * The line width specifies the thickness of the line used to stroke a path and is measured
     * in used space units.<BR>
     *
     * @param		w			a width
     */
    
    public void setLineWidth(float w) {
        content.append(w).append(" w").append_i(separator);
    }
    
    /**
     * Changes the <VAR>Miter limit</VAR>.
     * <P>
     * When two line segments meet at a sharp angle and mitered joins have been specified as the
     * line join style, it is possible for the miter to extend far beyond the thickness of the line
     * stroking path. The miter limit imposes a maximum on the ratio of the miter length to the line
     * witdh. When the limit is exceeded, the join is converted from a miter to a bevel.<BR>
     *
     * @param		miterLimit		a miter limit
     */
    
    public void setMiterLimit(float miterLimit) {
        if (miterLimit > 1) {
            content.append(miterLimit).append(" M").append_i(separator);
        }
    }
    
    /**
     * Modify the current clipping path by intersecting it with the current path, using the
     * nonzero winding number rule to determine which regions lie inside the clipping
     * path.
     */
    
    public void clip() {
        content.append("W").append_i(separator);
    }
    
    /**
     * Modify the current clipping path by intersecting it with the current path, using the
     * even-odd rule to determine which regions lie inside the clipping path.
     */
    
    public void eoClip() {
        content.append("W*").append_i(separator);
    }
    
    /**
     * Changes the currentgray tint for filling paths (device dependent colors!).
     * <P>
     * Sets the color space to <B>DeviceGray</B> (or the <B>DefaultGray</B> color space),
     * and sets the gray tint to use for filling paths.</P>
     *
     * @param	gray	a value between 0 (black) and 1 (white)
     */
    
    public void setGrayFill(float gray) {
        content.append(gray).append(" g").append_i(separator);
    }
    
    /**
     * Changes the current gray tint for filling paths to black.
     */
    
    public void resetGrayFill() {
        content.append("0 g").append_i(separator);
    }