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Barcode4J is a flexible generator for barcodes written in Java inclusive
extensions to support Apache FOP 0.93 and later.
The newest version!
/*
* Copyright 2006-2007 Jeremias Maerki or contributors to Barcode4J, as applicable.
*
* 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.
*/
/* $Id: PDF417LogicImpl.java,v 1.4 2007/07/11 08:22:41 jmaerki Exp $ */
package org.krysalis.barcode4j.impl.pdf417;
import java.awt.Dimension;
import org.krysalis.barcode4j.BarGroup;
import org.krysalis.barcode4j.ClassicBarcodeLogicHandler;
import org.krysalis.barcode4j.TwoDimBarcodeLogicHandler;
/**
* Top-level class for the logic part of the PDF417 implementation.
*
* @version $Id: PDF417LogicImpl.java,v 1.4 2007/07/11 08:22:41 jmaerki Exp $
*/
public class PDF417LogicImpl {
/**
* Calculates the necessary number of rows as described in annex Q of ISO/IEC 15438:2001(E).
* @param m the number of source codewords prior to the additional of the Symbol Length
* Descriptor and any pad codewords
* @param k the number of error correction codewords
* @param c the number of columns in the symbol in the data region (excluding start, stop and
* row indicator codewords)
* @return the number of rows in the symbol (r)
*/
public static int getNumberOfRows(int m, int k, int c) {
int r = calculateNumberOfRows(m, k, c);
if (r > 90) {
throw new IllegalArgumentException(
"The message doesn't fit in the configured symbol size."
+ " The resultant number of rows for this barcode exceeds 90."
+ " Please increase the number of columns or decrease the error correction"
+ " level to reduce the number of rows.");
}
if (r < 3) {
throw new IllegalArgumentException(
"The message is too short for the configured symbol size."
+ " The resultant number of rows is less than 3."
+ " Please decrease the number of columns or increase the error correction"
+ " level to increase the number of rows.");
}
return r;
}
/**
* Calculates the necessary number of rows as described in annex Q of ISO/IEC 15438:2001(E).
* @param m the number of source codewords prior to the additional of the Symbol Length
* Descriptor and any pad codewords
* @param k the number of error correction codewords
* @param c the number of columns in the symbol in the data region (excluding start, stop and
* row indicator codewords)
* @return the number of rows in the symbol (r)
*/
public static int calculateNumberOfRows(int m, int k, int c) {
int r = ((m + 1 + k) / c) + 1;
if (c * r >= (m + 1 + k + c)) {
r--;
}
return r;
}
/**
* Calculates the number of pad codewords as described in 4.9.2 of ISO/IEC 15438:2001(E).
* @param m the number of source codewords prior to the additional of the Symbol Length
* Descriptor and any pad codewords
* @param k the number of error correction codewords
* @param c the number of columns in the symbol in the data region (excluding start, stop and
* row indicator codewords)
* @param r the number of rows in the symbol
* @return the number of pad codewords
*/
public static int getNumberOfPadCodewords(int m, int k, int c, int r) {
int n = c * r - k;
if (n > m + 1) {
return (n - m) - 1;
} else {
return 0;
}
}
/**
* Calculates the number of data codewords (equals the Symbol Length Descriptor).
* @param m the number of source codewords prior to the additional of the Symbol Length
* Descriptor and any pad codewords
* @param errorCorrectionLevel the error correction level (value between 0 and 8)
* @param c the number of columns in the symbol in the data region (excluding start, stop and
* row indicator codewords)
* @return the number of data codewords
*/
public static int getNumberOfDataCodewords(int m, int errorCorrectionLevel, int c) {
int k = PDF417ErrorCorrection.getErrorCorrectionCodewordCount(errorCorrectionLevel);
int r = getNumberOfRows(m, k, c);
return c * r - k;
}
private static void encodeChar(int pattern, int len, ClassicBarcodeLogicHandler logic) {
int map = 1 << len - 1;
boolean last = (pattern & map) != 0; //Initialize to inverse of first bit
int width = 0;
for (int i = 0; i < len; i++) {
boolean black = (pattern & map) != 0;
if (last == black) {
width++;
} else {
logic.addBar(last, width);
last = black;
width = 1;
}
map >>= 1;
}
logic.addBar(last, width);
}
private static void encodeLowLevel(String fullCodewords, int c, int r,
int errorCorrectionLevel, TwoDimBarcodeLogicHandler logic) {
int idx = 0;
for (int y = 0; y < r; y++) {
int cluster = (y % 3);
logic.startRow();
logic.startBarGroup(BarGroup.START_CHARACTER, null);
encodeChar(PDF417Constants.START_PATTERN, 17, logic);
logic.endBarGroup();
int left, right;
if (cluster == 0) {
left = (30 * (y / 3)) + ((r - 1) / 3);
right = (30 * (y / 3)) + (c - 1);
} else if (cluster == 1) {
left = (30 * (y / 3)) + (errorCorrectionLevel * 3) + ((r - 1) % 3);
right = (30 * (y / 3)) + ((r - 1) / 3);
} else {
left = (30 * (y / 3)) + (c - 1);
right = (30 * (y / 3)) + (errorCorrectionLevel * 3) + ((r - 1) % 3);
}
int pattern;
logic.startBarGroup(BarGroup.MSG_CHARACTER, null);
pattern = PDF417Constants.CODEWORD_TABLE[cluster][left];
encodeChar(pattern, 17, logic);
logic.endBarGroup();
for (int x = 0; x < c; x++) {
logic.startBarGroup(BarGroup.MSG_CHARACTER, null);
pattern = PDF417Constants.CODEWORD_TABLE[cluster][fullCodewords.charAt(idx)];
encodeChar(pattern, 17, logic);
logic.endBarGroup();
idx++;
}
logic.startBarGroup(BarGroup.MSG_CHARACTER, null);
pattern = PDF417Constants.CODEWORD_TABLE[cluster][right];
encodeChar(pattern, 17, logic);
logic.endBarGroup();
logic.startBarGroup(BarGroup.STOP_CHARACTER, null);
encodeChar(PDF417Constants.STOP_PATTERN, 18, logic);
logic.endBarGroup();
logic.endRow();
}
}
/**
* Generates the barcode logic.
* @param logic the logic handler to receive generated events
* @param msg the message to encode
* @param pdf417Bean reference to the PDF417 bean for configuration access
*/
public static void generateBarcodeLogic(TwoDimBarcodeLogicHandler logic,
String msg, PDF417Bean pdf417Bean) {
int errorCorrectionLevel = pdf417Bean.getErrorCorrectionLevel();
//1. step: High-level encoding
int errorCorrectionCodeWords = PDF417ErrorCorrection.getErrorCorrectionCodewordCount(
errorCorrectionLevel);
String highLevel = PDF417HighLevelEncoder.encodeHighLevel(msg);
int sourceCodeWords = highLevel.length();
Dimension dimension = determineDimensions(pdf417Bean, sourceCodeWords);
if (dimension == null) {
throw new IllegalArgumentException(
"Unable to fit message in columns");
}
int rows = dimension.height;
int cols = dimension.width;
int pad = getNumberOfPadCodewords(sourceCodeWords,
errorCorrectionCodeWords, cols, rows);
//2. step: construct data codewords
int n = getNumberOfDataCodewords(sourceCodeWords, errorCorrectionLevel,
cols);
if (n > 929) {
throw new IllegalArgumentException(
"Encoded message contains to many code words, message to big ("
+ msg.length() + " bytes)");
}
StringBuffer sb = new StringBuffer(n);
sb.append((char)n);
sb.append(highLevel);
for (int i = 0; i < pad; i++) {
sb.append((char)900); //PAD characters
}
String dataCodewords = sb.toString();
//3. step: Error correction
String ec = PDF417ErrorCorrection.generateErrorCorrection(
dataCodewords, errorCorrectionLevel);
String fullCodewords = dataCodewords + ec;
//4. step: low-level encoding
logic.startBarcode(msg, msg);
encodeLowLevel(fullCodewords, cols, rows, errorCorrectionLevel, logic);
logic.endBarcode();
}
/**
* Determine optimal nr of columns and rows for the specified number of
* codewords.
* @param pdf417Bean contains configuration settings
* @param sourceCodeWords number of code words
* @return dimension object containing cols as width and rows as height
*/
public static Dimension determineDimensions(PDF417Bean pdf417Bean,
int sourceCodeWords) {
int minCols = pdf417Bean.getMinCols();
int maxCols = pdf417Bean.getMaxCols();
int maxRows = pdf417Bean.getMaxRows();
int minRows = pdf417Bean.getMinRows();
double preferredRatio = pdf417Bean.getWidthToHeightRatio();
double ratio = 0;
Dimension dimension = null;
int errorCorrectionCodeWords = PDF417ErrorCorrection.getErrorCorrectionCodewordCount(
pdf417Bean.getErrorCorrectionLevel());
for (int cols = minCols; cols <= maxCols; cols++) {
int rows = calculateNumberOfRows(sourceCodeWords,
errorCorrectionCodeWords, cols);
if (rows < minRows) {
break;
}
if (rows > maxRows) {
continue;
}
double newRatio = ((17 * cols + 69) * pdf417Bean.getModuleWidth())
/ (rows * pdf417Bean.getBarHeight());
// ignore if previous ratio is closer to preferred ratio
if (dimension != null
&& Math.abs(newRatio - preferredRatio) > Math.abs(ratio
- preferredRatio)) {
continue;
}
ratio = newRatio;
dimension = new Dimension(cols, rows);
}
return dimension;
}
}