papformatteddiskpage.java

Office格式转换代码

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
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 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache POI" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 * 5. Products derived from this software may not be called "Apache",
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 *
 * This software consists of voluntary contributions made by many
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 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.poi.hdf.model.hdftypes;

import org.apache.poi.util.LittleEndian;

/**
 * Represents a PAP FKP. The style properties for paragraph and character runs
 * are stored in fkps. There are PAP fkps for paragraph properties and CHP fkps
 * for character run properties. The first part of the fkp for both CHP and PAP
 * fkps consists of an array of 4 byte int offsets in the main stream for that
 * Paragraph's or Character run's text. The ending offset is the next
 * value in the array. For example, if an fkp has X number of Paragraph's
 * stored in it then there are (x + 1) 4 byte ints in the beginning array. The
 * number X is determined by the last byte in a 512 byte fkp.
 *
 * CHP and PAP fkps also store the compressed styles(grpprl) that correspond to
 * the offsets on the front of the fkp. The offset of the grpprls is determined
 * differently for CHP fkps and PAP fkps.
 *
 * @author Ryan Ackley
 */
public class PAPFormattedDiskPage extends FormattedDiskPage
{

    /**
     * Creates a PAPFormattedDiskPage from a 512 byte array
     *
     * @param fkp a 512 byte array.
     */
    public PAPFormattedDiskPage(byte[] fkp)
    {
        super(fkp);
    }

    /**
     * Gets the papx for the pagraph at index in this fkp.
     *
     * @param index The index of the papx to get.
     * @return a papx grpprl.
     */
    public byte[] getGrpprl(int index)
    {
        int papxOffset = 2 * LittleEndian.getUnsignedByte(_fkp, ((_crun + 1) * 4) + (index * 13));
        int size = 2 * LittleEndian.getUnsignedByte(_fkp, papxOffset);
        if(size == 0)
        {
            size = 2 * LittleEndian.getUnsignedByte(_fkp, ++papxOffset);
        }
        else
        {
            size--;
        }

        byte[] papx = new byte[size];
        System.arraycopy(_fkp, ++papxOffset, papx, 0, size);
        return papx;
    }
}