/*
* Copyright 2010 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.google.zxing.oned;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.Writer;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import java.util.Hashtable;
/**
* This object renders a UPC-A code as a {@link BitMatrix}.
*
* @author qwandor@google.com (Andrew Walbran)
*/
public class UPCAWriter implements Writer {
private final EAN13Writer subWriter = new EAN13Writer();
public BitMatrix encode(String contents, BarcodeFormat format, int width, int height)
throws WriterException {
return encode(contents, format, width, height, null);
}
public BitMatrix encode(String contents, BarcodeFormat format, int width, int height, Hashtable hints)
throws WriterException {
if (format != BarcodeFormat.UPC_A) {
throw new IllegalArgumentException("Can only encode UPC-A, but got " + format);
}
return subWriter.encode(preencode(contents), BarcodeFormat.EAN_13, width, height, hints);
}
/**
* Transform a UPC-A code into the equivalent EAN-13 code, and add a check digit if it is not
* already present.
*/
private static String preencode(String contents) {
int length = contents.length();
if (length == 11) {
// No check digit present, calculate it and add it
int sum = 0;
for (int i = 0; i < 11; ++i) {
sum += (contents.charAt(i) - '0') * (i % 2 == 0 ? 3 : 1);
}
contents += (1000 - sum) % 10;
} else if (length != 12) {
throw new IllegalArgumentException(
"Requested contents should be 11 or 12 digits long, but got " + contents.length());
}
return '0' + contents;
}
}