iText 5 itextpdf.jar Source Code

itextpdf.jar is a component in iText 5 Java library to provide core functionalities. iText Java library allows you to generate and manage PDF documents.

The Source Code files are provided at iText GitHub site.

You can compile it to generate your JAR file, using pom.xml as the build configuration file.

The source code of itextpdf-5.5.14.jar is provided below:

✍: FYIcenter.com

com/itextpdf/text/pdf/codec/GifImage.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 iText Group NV
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program 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 Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf.codec;

import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.Image;
import com.itextpdf.text.ImgRaw;
import com.itextpdf.text.Utilities;
import com.itextpdf.text.error_messages.MessageLocalization;
import com.itextpdf.text.pdf.*;

import java.io.*;
import java.net.URL;
import java.util.ArrayList;

/** Reads gif images of all types. All the images in a gif are read in the constructors
 * and can be retrieved with other methods.
 * @author Paulo Soares
 */
public class GifImage {

    protected DataInputStream in;
    protected int width;            // full image width
    protected int height;           // full image height
    protected boolean gctFlag;      // global color table used

    protected int bgIndex;          // background color index
    protected int bgColor;          // background color
    protected int pixelAspect;      // pixel aspect ratio

    protected boolean lctFlag;      // local color table flag
    protected boolean interlace;    // interlace flag
    protected int lctSize;          // local color table size

    protected int ix, iy, iw, ih;   // current image rectangle

    protected byte[] block = new byte[256];  // current data block
    protected int blockSize = 0;    // block size

    // last graphic control extension info
    protected int dispose = 0;   // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
    protected boolean transparency = false;   // use transparent color
    protected int delay = 0;        // delay in milliseconds
    protected int transIndex;       // transparent color index

    protected static final int MaxStackSize = 4096;   // max decoder pixel stack size

    // LZW decoder working arrays
    protected short[] prefix;
    protected byte[] suffix;
    protected byte[] pixelStack;
    protected byte[] pixels;

    protected byte m_out[];
    protected int m_bpc;
    protected int m_gbpc;
    protected byte m_global_table[];
    protected byte m_local_table[];
    protected byte m_curr_table[];
    protected int m_line_stride;
    protected byte fromData[];
    protected URL fromUrl;


    protected ArrayList<GifFrame> frames = new ArrayList<GifFrame>();     // frames read from current file

    /** Reads gif images from an URL.
     * @param url the URL
     * @throws IOException on error
     */
    public GifImage(URL url) throws IOException {
        fromUrl = url;
        InputStream is = null;
        try {
            is = url.openStream();

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = is.read(bytes)) != -1) {
                baos.write(bytes, 0, read);
            }
            is.close();

            is = new ByteArrayInputStream(baos.toByteArray());
            baos.flush();
            baos.close();

            process(is);
        }
        finally {
            if (is != null) {
                is.close();
            }
        }
    }

    /** Reads gif images from a file.
     * @param file the file
     * @throws IOException on error
     */
    public GifImage(String file) throws IOException {
        this(Utilities.toURL(file));
    }

    /** Reads gif images from a byte array.
     * @param data the byte array
     * @throws IOException on error
     */
    public GifImage(byte data[]) throws IOException {
        fromData = data;
        InputStream is = null;
        try {
            is = new ByteArrayInputStream(data);
            process(is);
        }
        finally {
            if (is != null) {
                is.close();
            }
        }
    }

    /** Reads gif images from a stream. The stream is not closed.
     * @param is the stream
     * @throws IOException on error
     */
    public GifImage(InputStream is) throws IOException {
        process(is);
    }

    /** Gets the number of frames the gif has.
     * @return the number of frames the gif has
     */
    public int getFrameCount() {
        return frames.size();
    }

    /** Gets the image from a frame. The first frame is 1.
     * @param frame the frame to get the image from
     * @return the image
     */
    public Image getImage(int frame) {
        GifFrame gf = frames.get(frame - 1);
        return gf.image;
    }

    /** Gets the [x,y] position of the frame in reference to the
     * logical screen.
     * @param frame the frame
     * @return the [x,y] position of the frame
     */
    public int[] getFramePosition(int frame) {
        GifFrame gf = frames.get(frame - 1);
        return new int[]{gf.ix, gf.iy};

    }

    /** Gets the logical screen. The images may be smaller and placed
     * in some position in this screen to playback some animation.
     * No image will be be bigger that this.
     * @return the logical screen dimensions as [x,y]
     */
    public int[] getLogicalScreen() {
        return new int[]{width, height};
    }

    void process(InputStream is) throws IOException {
        in = new DataInputStream(new BufferedInputStream(is));
        readHeader();
        readContents();
        if (frames.isEmpty())
            throw new IOException(MessageLocalization.getComposedMessage("the.file.does.not.contain.any.valid.image"));
    }

    /**
     * Reads GIF file header information.
     */
    protected void readHeader() throws IOException {
        StringBuilder id = new StringBuilder("");
        for (int i = 0; i < 6; i++)
            id.append((char)in.read());
        if (!id.toString().startsWith("GIF8")) {
            throw new IOException(MessageLocalization.getComposedMessage("gif.signature.nor.found"));
        }

        readLSD();
        if (gctFlag) {
            m_global_table = readColorTable(m_gbpc);
        }
    }

    /**
     * Reads Logical Screen Descriptor
     */
    protected void readLSD() throws IOException {

        // logical screen size
        width = readShort();
        height = readShort();

        // packed fields
        int packed = in.read();
        gctFlag = (packed & 0x80) != 0;      // 1   : global color table flag
        m_gbpc = (packed & 7) + 1;
        bgIndex = in.read();        // background color index
        pixelAspect = in.read();    // pixel aspect ratio
    }

    /**
     * Reads next 16-bit value, LSB first
     */
    protected int readShort() throws IOException {
        // read 16-bit value, LSB first
        return in.read() | in.read() << 8;
    }

    /**
     * Reads next variable length block from input.
     *
     * @return number of bytes stored in "buffer"
     */
    protected int readBlock() throws IOException {
        blockSize = in.read();
        if (blockSize <= 0)
            return blockSize = 0;

        blockSize = in.read(block, 0, blockSize);

        return blockSize;
    }

    protected byte[] readColorTable(int bpc) throws IOException {
        int ncolors = 1 << bpc;
        int nbytes = 3*ncolors;
        bpc = newBpc(bpc);
        byte table[] = new byte[(1 << bpc) * 3];
        in.readFully(table, 0, nbytes);
        return table;
    }


    static protected int newBpc(int bpc) {
        switch (bpc) {
            case 1:
            case 2:
            case 4:
                break;
            case 3:
                return 4;
            default:
                return 8;
        }
        return bpc;
    }

    protected void readContents() throws IOException {
        // read GIF file content blocks
        boolean done = false;
        while (!done) {
            int code = in.read();
            switch (code) {

                case 0x2C:    // image separator
                    readImage();
                    break;

                case 0x21:    // extension
                    code = in.read();
                    switch (code) {

                        case 0xf9:    // graphics control extension
                            readGraphicControlExt();
                            break;

                        case 0xff:    // application extension
                            readBlock();
                            skip();        // don't care
                            break;

                        default:    // uninteresting extension
                            skip();
                    }
                    break;

                default:
                    done = true;
                    break;
            }
        }
    }

    /**
     * Reads next frame image
     */
    protected void readImage() throws IOException {
        ix = readShort();    // (sub)image position & size
        iy = readShort();
        iw = readShort();
        ih = readShort();

        int packed = in.read();
        lctFlag = (packed & 0x80) != 0;     // 1 - local color table flag
        interlace = (packed & 0x40) != 0;   // 2 - interlace flag
        // 3 - sort flag
        // 4-5 - reserved
        lctSize = 2 << (packed & 7);        // 6-8 - local color table size
        m_bpc = newBpc(m_gbpc);
        if (lctFlag) {
            m_curr_table = readColorTable((packed & 7) + 1);   // read table
            m_bpc = newBpc((packed & 7) + 1);
        }
        else {
            m_curr_table = m_global_table;
        }
        if (transparency && transIndex >= m_curr_table.length / 3)
            transparency = false;
        if (transparency && m_bpc == 1) { // Acrobat 5.05 doesn't like this combination
            byte tp[] = new byte[12];
            System.arraycopy(m_curr_table, 0, tp, 0, 6);
            m_curr_table = tp;
            m_bpc = 2;
        }
        boolean skipZero = decodeImageData();   // decode pixel data
        if (!skipZero)
            skip();

        Image img = null;
        try {
            img = new ImgRaw(iw, ih, 1, m_bpc, m_out);
            PdfArray colorspace = new PdfArray();
            colorspace.add(PdfName.INDEXED);
            colorspace.add(PdfName.DEVICERGB);
            int len = m_curr_table.length;
            colorspace.add(new PdfNumber(len / 3 - 1));
            colorspace.add(new PdfString(m_curr_table));
            PdfDictionary ad = new PdfDictionary();
            ad.put(PdfName.COLORSPACE, colorspace);
            img.setAdditional(ad);
            if (transparency) {
                img.setTransparency(new int[]{transIndex, transIndex});
            }
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
        img.setOriginalType(Image.ORIGINAL_GIF);
        img.setOriginalData(fromData);
        img.setUrl(fromUrl);
        GifFrame gf = new GifFrame();
        gf.image = img;
        gf.ix = ix;
        gf.iy = iy;
        frames.add(gf);   // add image to frame list

        //resetFrame();

    }

    protected boolean decodeImageData() throws IOException {
        int NullCode = -1;
        int npix = iw * ih;
        int available, clear, code_mask, code_size, end_of_information, in_code, old_code,
        bits, code, count, i, datum, data_size, first, top, bi;
        boolean skipZero = false;

        if (prefix == null)
            prefix = new short[MaxStackSize];
        if (suffix == null)
            suffix = new byte[MaxStackSize];
        if (pixelStack == null)
            pixelStack = new byte[MaxStackSize+1];

        m_line_stride = (iw * m_bpc + 7) / 8;
        m_out = new byte[m_line_stride * ih];
        int pass = 1;
        int inc = interlace ? 8 : 1;
        int line = 0;
        int xpos = 0;

        //  Initialize GIF data stream decoder.

        data_size = in.read();
        clear = 1 << data_size;
        end_of_information = clear + 1;
        available = clear + 2;
        old_code = NullCode;
        code_size = data_size + 1;
        code_mask = (1 << code_size) - 1;
        for (code = 0; code < clear; code++) {
            prefix[code] = 0;
            suffix[code] = (byte) code;
        }

        //  Decode GIF pixel stream.

        datum = bits = count = first = top = bi = 0;

        for (i = 0; i < npix; ) {
            if (top == 0) {
                if (bits < code_size) {
                    //  Load bytes until there are enough bits for a code.
                    if (count == 0) {
                        // Read a new data block.
                        count = readBlock();
                        if (count <= 0) {
                            skipZero = true;
                            break;
                        }
                        bi = 0;
                    }
                    datum += (block[bi] & 0xff) << bits;
                    bits += 8;
                    bi++;
                    count--;
                    continue;
                }

                //  Get the next code.

                code = datum & code_mask;
                datum >>= code_size;
                bits -= code_size;

                //  Interpret the code

                if (code > available || code == end_of_information)
                    break;
                if (code == clear) {
                    //  Reset decoder.
                    code_size = data_size + 1;
                    code_mask = (1 << code_size) - 1;
                    available = clear + 2;
                    old_code = NullCode;
                    continue;
                }
                if (old_code == NullCode) {
                    pixelStack[top++] = suffix[code];
                    old_code = code;
                    first = code;
                    continue;
                }
                in_code = code;
                if (code == available) {
                    pixelStack[top++] = (byte) first;
                    code = old_code;
                }
                while (code > clear) {
                    pixelStack[top++] = suffix[code];
                    code = prefix[code];
                }
                first = suffix[code] & 0xff;

                //  Add a new string to the string table,

                if (available >= MaxStackSize)
                    break;
                pixelStack[top++] = (byte) first;
                prefix[available] = (short) old_code;
                suffix[available] = (byte) first;
                available++;
                if ((available & code_mask) == 0 && available < MaxStackSize) {
                    code_size++;
                    code_mask += available;
                }
                old_code = in_code;
            }

            //  Pop a pixel off the pixel stack.

            top--;
            i++;

            setPixel(xpos, line, pixelStack[top]);
            ++xpos;
            if (xpos >= iw) {
                xpos = 0;
                line += inc;
                if (line >= ih) {
                    if (interlace) {
                        do {
                            pass++;
                            switch (pass) {
                                case 2:
                                    line = 4;
                                    break;
                                case 3:
                                    line = 2;
                                    inc = 4;
                                    break;
                                case 4:
                                    line = 1;
                                    inc = 2;
                                    break;
                                default: // this shouldn't happen
                                    line = ih - 1;
                                    inc = 0;
                            }
                        } while (line >= ih);
                    }
                    else {
                        line = ih - 1; // this shouldn't happen
                        inc = 0;
                    }
                }
            }
        }
        return skipZero;
    }


    protected void setPixel(int x, int y, int v) {
        if (m_bpc == 8) {
            int pos = x + iw * y;
            m_out[pos] = (byte)v;
        }
        else {
            int pos = m_line_stride * y + x / (8 / m_bpc);
            int vout = v << 8 - m_bpc * (x % (8 / m_bpc))- m_bpc;
            m_out[pos] |= vout;
        }
    }

    /**
     * Resets frame state for reading next image.
     */
    protected void resetFrame() {
        // it does nothing in the pdf context
        //boolean transparency = false;
        //int delay = 0;
    }

    /**
     * Reads Graphics Control Extension values
     */
    protected void readGraphicControlExt() throws IOException {
        in.read();    // block size
        int packed = in.read();   // packed fields
        dispose = (packed & 0x1c) >> 2;   // disposal method
        if (dispose == 0)
            dispose = 1;   // elect to keep old image if discretionary
        transparency = (packed & 1) != 0;
        delay = readShort() * 10;   // delay in milliseconds
        transIndex = in.read();        // transparent color index
        in.read();                     // block terminator
    }

    /**
     * Skips variable length blocks up to and including
     * next zero length block.
     */
    protected void skip() throws IOException {
        do {
            readBlock();
        } while (blockSize > 0);
    }

    static class GifFrame {
        Image image;
        int ix;
        int iy;
    }
}

com/itextpdf/text/pdf/codec/GifImage.java

 

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⇐ iText layout.jar Source Code

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⇑⇑ iText for PDF Generation

2021-07-03, 47715👍, 0💬