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Added some 'if' braces, changes C-comments to javadocs -- minor stuff

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git-svn-id: https://zxing.googlecode.com/svn/trunk@92 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2007-12-06 20:47:05 +00:00
parent 0ce5a5c57d
commit 611e057250
1 changed files with 39 additions and 28 deletions
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67
core/src/com/google/zxing/upc/UPCDecoder.java
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@ -17,8 +17,8 @@
package com.google.zxing.upc;
import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.common.BitArray;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.common.BitArray;
/**
* This class takes a bitmap, and attempts to return a String which is the contents of the UPC
@ -45,7 +45,7 @@ final class UPCDecoder {
{ 30, 10, 10, 20 } // 9
};
// Alternative even-parity patterns for EAN-13 barcodes
/** Alternative even-parity patterns for EAN-13 barcodes. */
private static final byte[][] EVEN_PARITY_PATTERNS = {
{ 10, 10, 20, 30 }, // 0
{ 10, 20, 20, 20 }, // 1
@ -97,10 +97,11 @@ final class UPCDecoder {
private static final int UNKNOWN_PARITY = 0;
private static final int ODD_PARITY = 1;
private static final int EVEN_PARITY = 2;
// Utility class for returning a matched character. Defines the character
// plus the parity used for encoding it.
/**
* Utility class for returning a matched character. Defines the character
* plus the parity used for encoding it.
*/
private static class CharResult {
public char character; // the encoded character
public int parity; // one of the parity types above
@ -119,10 +120,12 @@ final class UPCDecoder {
height = bitmap.getHeight();
}
// To decode the image, we follow a search pattern defined in kBitmapSearchPattern. It is a
// list of percentages which translate to row numbers to scan across. For each row, we scan
// left to right, and if that fails, we reverse the row in place and try again to see if the
// bar code was upside down.
/**
* To decode the image, we follow a search pattern defined in kBitmapSearchPattern. It is a
* list of percentages which translate to row numbers to scan across. For each row, we scan
* left to right, and if that fails, we reverse the row in place and try again to see if the
* bar code was upside down.
*/
String decode() {
BitArray rowData = new BitArray(width);
String longestResult = "";
@ -196,21 +199,23 @@ final class UPCDecoder {
return verifyResult();
}
// Verifies the checksum. This is computed by adding up digits in the even
// indices (0, 2, 4...) then adding the digits in the odd indices (1, 3, 5..)
// and multiplying by 3. The total, plus the final checksum digit, should be
// divisible by 10.
//
// Note that for a UPC barcode, we add the additional '0' to the front
// (converting it to a EAN-13 code) for purposes of calculating the checksum
//
/**
* Verifies the checksum. This is computed by adding up digits in the even
* indices (0, 2, 4...) then adding the digits in the odd indices (1, 3, 5..)
* and multiplying by 3. The total, plus the final checksum digit, should be
* divisible by 10.
*
* Note that for a UPC barcode, we add the additional '0' to the front
* (converting it to a EAN-13 code) for purposes of calculating the checksum
*/
private boolean verifyResult() {
// TODO - handle compressed barcodes.
// length is 12 for UPC and 13 for EAN-13
if (result.length() != 12 && result.length() != 13)
if (result.length() != 12 && result.length() != 13) {
return false;
}
int checksum = 0;
int end = result.length()-2;
@ -231,7 +236,6 @@ final class UPCDecoder {
private int decodeOneSide(BitArray rowData, int rowOffset, boolean checkBothParities) {
int[] counters = new int[4];
byte firstDigitPattern = 0;
char firstDigit = '-';
for (int x = 0; x < 6 && rowOffset < width; x++) {
recordPattern(rowData, rowOffset, counters, 4);
for (int y = 0; y < 4; y++) {
@ -239,28 +243,35 @@ final class UPCDecoder {
}
CharResult foundChar = new CharResult();
findDigit(counters, foundChar, checkBothParities);
if (foundChar.parity == UNKNOWN_PARITY)
if (foundChar.parity == UNKNOWN_PARITY) {
return -1;
if (foundChar.parity == EVEN_PARITY)
firstDigitPattern |= 1 << (5-x);
}
if (foundChar.parity == EVEN_PARITY) {
firstDigitPattern |= 1 << (5 - x);
}
result.append(foundChar.character);
}
char firstDigit = '-';
for (int i = 0; i < FIRST_DIGIT_ENCODINGS.length; i++) {
if (firstDigitPattern == FIRST_DIGIT_ENCODINGS[i]) {
firstDigit = (char) ((int) '0' + i);
break;
}
}
if (firstDigit == '-')
if (firstDigit == '-') {
return -1;
if (firstDigit != '0')
}
if (firstDigit != '0') {
result.insert(0, firstDigit);
}
return rowOffset;
}
// Returns the horizontal position just after the pattern was found if successful, otherwise
// returns -1 if the pattern was not found. Searches are always left to right, and patterns
// begin on white or black based on the flag.
/**
* Returns the horizontal position just after the pattern was found if successful, otherwise
* returns -1 if the pattern was not found. Searches are always left to right, and patterns
* begin on white or black based on the flag.
*/
private int findPattern(BitArray rowData, int rowOffset, byte[] pattern, boolean whiteFirst) {
int[] counters = new int[pattern.length];
int width = this.width;