pict.java

java 读写word excel ppt

/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (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.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================== */
package org.apache.poi.hslf.blip;

import org.apache.poi.hslf.model.Picture;
import org.apache.poi.hslf.model.Shape;
import org.apache.poi.hslf.exceptions.HSLFException;
import org.apache.poi.util.LittleEndian;

import java.io.*;
import java.util.zip.InflaterInputStream;
import java.util.zip.DeflaterOutputStream;

/**
 * Represents Macintosh PICT picture data.
 * 
 * @author Yegor Kozlov
 */
public class PICT extends Metafile {

    public PICT(){
        super();
    }

    /**
     * Extract compressed PICT data from a ppt
     */
    public byte[] getData(){
        byte[] rawdata = getRawData();
        try {
            byte[] macheader = new byte[512];
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            out.write(macheader);
            int pos = CHECKSUM_SIZE;
            byte[] pict;
            try {
                pict = read(rawdata, pos);
            } catch (IOException e){
                //weird MAC behaviour.
                //if failed to read right after the checksum - skip 16 bytes and try again
                pict = read(rawdata, pos + 16);
            }
            out.write(pict);
            return out.toByteArray();
        } catch (IOException e){
            throw new HSLFException(e);
        }
    }

    private byte[] read(byte[] data, int pos) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream bis = new ByteArrayInputStream(data);
        Header header = new Header();
        header.read(data, pos);
        bis.skip(pos + header.getSize());
        InflaterInputStream inflater = new InflaterInputStream( bis );
        byte[] chunk = new byte[4096];
        int count;
        while ((count = inflater.read(chunk)) >=0 ) {
            out.write(chunk,0,count);
        }
        inflater.close();
        return out.toByteArray();
    }

    public void setData(byte[] data) throws IOException {
        int pos = 512; //skip the first 512 bytes - they are MAC specific crap
        byte[] compressed = compress(data, pos, data.length-pos);

        Header header = new Header();
        header.wmfsize = data.length - 512;
        //we don't have a PICT reader in java, have to set default image size  200x200
        header.bounds = new java.awt.Rectangle(0, 0, 200, 200);
        header.size = new java.awt.Dimension(header.bounds.width*Shape.EMU_PER_POINT,
                header.bounds.height*Shape.EMU_PER_POINT);
        header.zipsize = compressed.length;

        byte[] checksum = getChecksum(data);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        out.write(checksum);

        out.write(new byte[16]); //16-byte prefix which is safe to ignore
        header.write(out);
        out.write(compressed);

        setRawData(out.toByteArray());
    }

    /**
     * @see org.apache.poi.hslf.model.Picture#PICT
     */
    public int getType(){
        return Picture.PICT;
    }

    /**
     * PICT signature is <code>0x5430</code>
     *
     * @return PICT signature (<code>0x5430</code>)
     */
    public int getSignature(){
        return 0x5430;
    }

}