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:

⏎ com/itextpdf/text/pdf/qrcode/QRCodeWriter.java

/*
 * Copyright 2008 ZXing authors
 *
 * Licensed 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 com.itextpdf.text.pdf.qrcode;


import java.util.Map;

/**
 * This object renders a QR Code as a ByteMatrix 2D array of greyscale values.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 * @since 5.0.2
 */
public final class QRCodeWriter {

  private static final int QUIET_ZONE_SIZE = 4;

  public ByteMatrix encode(String contents, int width, int height)
      throws WriterException {

    return encode(contents, width, height, null);
  }

  public ByteMatrix encode(String contents, int width, int height,
      Map<EncodeHintType,Object> hints) throws WriterException {

    if (contents == null || contents.length() == 0) {
      throw new IllegalArgumentException("Found empty contents");
    }

    if (width < 0 || height < 0) {
      throw new IllegalArgumentException("Requested dimensions are too small: " + width + 'x' +
          height);
    }

    ErrorCorrectionLevel errorCorrectionLevel = ErrorCorrectionLevel.L;
    if (hints != null) {
      ErrorCorrectionLevel requestedECLevel = (ErrorCorrectionLevel) hints.get(EncodeHintType.ERROR_CORRECTION);
      if (requestedECLevel != null) {
        errorCorrectionLevel = requestedECLevel;
      }
    }

    QRCode code = new QRCode();
    Encoder.encode(contents, errorCorrectionLevel, hints, code);
    return renderResult(code, width, height);
  }

  // Note that the input matrix uses 0 == white, 1 == black, while the output matrix uses
  // 0 == black, 255 == white (i.e. an 8 bit greyscale bitmap).
  private static ByteMatrix renderResult(QRCode code, int width, int height) {
    ByteMatrix input = code.getMatrix();
    int inputWidth = input.getWidth();
    int inputHeight = input.getHeight();
    int qrWidth = inputWidth + (QUIET_ZONE_SIZE << 1);
    int qrHeight = inputHeight + (QUIET_ZONE_SIZE << 1);
    int outputWidth = Math.max(width, qrWidth);
    int outputHeight = Math.max(height, qrHeight);

    int multiple = Math.min(outputWidth / qrWidth, outputHeight / qrHeight);
    // Padding includes both the quiet zone and the extra white pixels to accommodate the requested
    // dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone.
    // If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will
    // handle all the padding from 100x100 (the actual QR) up to 200x160.
    int leftPadding = (outputWidth - (inputWidth * multiple)) / 2;
    int topPadding = (outputHeight - (inputHeight * multiple)) / 2;

    ByteMatrix output = new ByteMatrix(outputWidth, outputHeight);
    byte[][] outputArray = output.getArray();

    // We could be tricky and use the first row in each set of multiple as the temporary storage,
    // instead of allocating this separate array.
    byte[] row = new byte[outputWidth];

    // 1. Write the white lines at the top
    for (int y = 0; y < topPadding; y++) {
      setRowColor(outputArray[y], (byte) 255);
    }

    // 2. Expand the QR image to the multiple
    byte[][] inputArray = input.getArray();
    for (int y = 0; y < inputHeight; y++) {
      // a. Write the white pixels at the left of each row
      for (int x = 0; x < leftPadding; x++) {
        row[x] = (byte) 255;
      }

      // b. Write the contents of this row of the barcode
      int offset = leftPadding;
      for (int x = 0; x < inputWidth; x++) {
        byte value = (inputArray[y][x] == 1) ? 0 : (byte) 255;
        for (int z = 0; z < multiple; z++) {
          row[offset + z] = value;
        }
        offset += multiple;
      }

      // c. Write the white pixels at the right of each row
      offset = leftPadding + (inputWidth * multiple);
      for (int x = offset; x < outputWidth; x++) {
        row[x] = (byte) 255;
      }

      // d. Write the completed row multiple times
      offset = topPadding + (y * multiple);
      for (int z = 0; z < multiple; z++) {
        System.arraycopy(row, 0, outputArray[offset + z], 0, outputWidth);
      }
    }

    // 3. Write the white lines at the bottom
    int offset = topPadding + (inputHeight * multiple);
    for (int y = offset; y < outputHeight; y++) {
      setRowColor(outputArray[y], (byte) 255);
    }

    return output;
  }

  private static void setRowColor(byte[] row, byte value) {
    for (int x = 0; x < row.length; x++) {
      row[x] = value;
    }
  }

}

⏎ com/itextpdf/text/pdf/qrcode/QRCodeWriter.java

Or download all of them as a single archive file:

File name: itextpdf-5.5.14-fyi.zip
File size: 2163839 bytes
Release date: 2009-10-09
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⇒ iText-2.1.6.jar - iText, a JAVA-PDF library

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