moved java files for pre-convert

src/oned/EAN13Reader.java

@@ -0,0 +1,138 @@
+/*
+ * 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.google.zxing.oned;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.common.BitArray;
+
+/**
+ * <p>Implements decoding of the EAN-13 format.</p>
+ *
+ * @author dswitkin@google.com (Daniel Switkin)
+ * @author Sean Owen
+ * @author alasdair@google.com (Alasdair Mackintosh)
+ */
+public final class EAN13Reader extends UPCEANReader {
+
+  // For an EAN-13 barcode, the first digit is represented by the parities used
+  // to encode the next six digits, according to the table below. For example,
+  // if the barcode is 5 123456 789012 then the value of the first digit is
+  // signified by using odd for '1', even for '2', even for '3', odd for '4',
+  // odd for '5', and even for '6'. See http://en.wikipedia.org/wiki/EAN-13
+  //
+  //                Parity of next 6 digits
+  //    Digit   0     1     2     3     4     5
+  //       0    Odd   Odd   Odd   Odd   Odd   Odd
+  //       1    Odd   Odd   Even  Odd   Even  Even
+  //       2    Odd   Odd   Even  Even  Odd   Even
+  //       3    Odd   Odd   Even  Even  Even  Odd
+  //       4    Odd   Even  Odd   Odd   Even  Even
+  //       5    Odd   Even  Even  Odd   Odd   Even
+  //       6    Odd   Even  Even  Even  Odd   Odd
+  //       7    Odd   Even  Odd   Even  Odd   Even
+  //       8    Odd   Even  Odd   Even  Even  Odd
+  //       9    Odd   Even  Even  Odd   Even  Odd
+  //
+  // Note that the encoding for '0' uses the same parity as a UPC barcode. Hence
+  // a UPC barcode can be converted to an EAN-13 barcode by prepending a 0.
+  //
+  // The encoding is represented by the following array, which is a bit pattern
+  // using Odd = 0 and Even = 1. For example, 5 is represented by:
+  //
+  //              Odd Even Even Odd Odd Even
+  // in binary:
+  //                0    1    1   0   0    1   == 0x19
+  //
+  static final int[] FIRST_DIGIT_ENCODINGS = {
+      0x00, 0x0B, 0x0D, 0xE, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A
+  };
+
+  private final int[] decodeMiddleCounters;
+
+  public EAN13Reader() {
+    decodeMiddleCounters = new int[4];
+  }
+
+  @Override
+  protected int decodeMiddle(BitArray row,
+                             int[] startRange,
+                             StringBuilder resultString) throws NotFoundException {
+    int[] counters = decodeMiddleCounters;
+    counters[0] = 0;
+    counters[1] = 0;
+    counters[2] = 0;
+    counters[3] = 0;
+    int end = row.getSize();
+    int rowOffset = startRange[1];
+
+    int lgPatternFound = 0;
+
+    for (int x = 0; x < 6 && rowOffset < end; x++) {
+      int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
+      resultString.append((char) ('0' + bestMatch % 10));
+      for (int counter : counters) {
+        rowOffset += counter;
+      }
+      if (bestMatch >= 10) {
+        lgPatternFound |= 1 << (5 - x);
+      }
+    }
+
+    determineFirstDigit(resultString, lgPatternFound);
+
+    int[] middleRange = findGuardPattern(row, rowOffset, true, MIDDLE_PATTERN);
+    rowOffset = middleRange[1];
+
+    for (int x = 0; x < 6 && rowOffset < end; x++) {
+      int bestMatch = decodeDigit(row, counters, rowOffset, L_PATTERNS);
+      resultString.append((char) ('0' + bestMatch));
+      for (int counter : counters) {
+        rowOffset += counter;
+      }
+    }
+
+    return rowOffset;
+  }
+
+  @Override
+  BarcodeFormat getBarcodeFormat() {
+    return BarcodeFormat.EAN_13;
+  }
+
+  /**
+   * Based on pattern of odd-even ('L' and 'G') patterns used to encoded the explicitly-encoded
+   * digits in a barcode, determines the implicitly encoded first digit and adds it to the
+   * result string.
+   *
+   * @param resultString string to insert decoded first digit into
+   * @param lgPatternFound int whose bits indicates the pattern of odd/even L/G patterns used to
+   *  encode digits
+   * @throws NotFoundException if first digit cannot be determined
+   */
+  private static void determineFirstDigit(StringBuilder resultString, int lgPatternFound)
+      throws NotFoundException {
+    for (int d = 0; d < 10; d++) {
+      if (lgPatternFound == FIRST_DIGIT_ENCODINGS[d]) {
+        resultString.insert(0, (char) ('0' + d));
+        return;
+      }
+    }
+    throw NotFoundException.getNotFoundInstance();
+  }
+
+}