下面列出了com.google.zxing.common.BitArray#getNextUnset ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* Records the size of all runs of white and black pixels, starting with white.
* This is just like recordPattern, except it records all the counters, and
* uses our builtin "counters" member for storage.
* @param row row to count from
*/
private void setCounters(BitArray row) throws NotFoundException {
counterLength = 0;
// Start from the first white bit.
int i = row.getNextUnset(0);
int end = row.getSize();
if (i >= end) {
throw NotFoundException.getNotFoundInstance();
}
boolean isWhite = true;
int count = 0;
while (i < end) {
if (row.get(i) != isWhite) {
count++;
} else {
counterAppend(count);
count = 1;
isWhite = !isWhite;
}
i++;
}
counterAppend(count);
}
/**
* Records the size of all runs of white and black pixels, starting with white.
* This is just like recordPattern, except it records all the counters, and
* uses our builtin "counters" member for storage.
* @param row row to count from
*/
private void setCounters(BitArray row) throws NotFoundException {
counterLength = 0;
// Start from the first white bit.
int i = row.getNextUnset(0);
int end = row.getSize();
if (i >= end) {
throw NotFoundException.getNotFoundInstance();
}
boolean isWhite = true;
int count = 0;
while (i < end) {
if (row.get(i) ^ isWhite) { // that is, exactly one is true
count++;
} else {
counterAppend(count);
count = 1;
isWhite = !isWhite;
}
i++;
}
counterAppend(count);
}
private 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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
checkParity |= 1 << (1 - x);
}
if (x != 1) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 2) {
throw NotFoundException.getNotFoundInstance();
}
if (Integer.parseInt(resultString.toString()) % 4 != checkParity) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
private static int getNextSecondBar(BitArray row, int initialPos){
int currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
private static int getNextSecondBar(BitArray row, int initialPos) {
int currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
private 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 < 5 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x != 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 5) {
throw NotFoundException.getNotFoundInstance();
}
int checkDigit = determineCheckDigit(lgPatternFound);
if (extensionChecksum(resultString.toString()) != checkDigit) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
/**
* @param row row of black/white values to search
* @param rowOffset position to start search
* @param whiteFirst if true, indicates that the pattern specifies white/black/white/...
* pixel counts, otherwise, it is interpreted as black/white/black/...
* @param pattern pattern of counts of number of black and white pixels that are being
* searched for as a pattern
* @param counters array of counters, as long as pattern, to re-use
* @return start/end horizontal offset of guard pattern, as an array of two ints
* @throws NotFoundException if pattern is not found
*/
private static int[] findGuardPattern(BitArray row,
int rowOffset,
boolean whiteFirst,
int[] pattern,
int[] counters) throws NotFoundException {
int patternLength = pattern.length;
int width = row.getSize();
boolean isWhite = whiteFirst;
rowOffset = whiteFirst ? row.getNextUnset(rowOffset) : row.getNextSet(rowOffset);
int counterPosition = 0;
int patternStart = rowOffset;
for (int x = rowOffset; x < width; x++) {
if (row.get(x) ^ isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition == patternLength - 1) {
if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE) {
return new int[]{patternStart, x};
}
patternStart += counters[0] + counters[1];
System.arraycopy(counters, 2, counters, 0, patternLength - 2);
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw NotFoundException.getNotFoundInstance();
}
/**
* @param row row of black/white values to search
* @param rowOffset position to start search
* @param whiteFirst if true, indicates that the pattern specifies white/black/white/...
* pixel counts, otherwise, it is interpreted as black/white/black/...
* @param pattern pattern of counts of number of black and white pixels that are being
* searched for as a pattern
* @param counters array of counters, as long as pattern, to re-use
* @return start/end horizontal offset of guard pattern, as an array of two ints
* @throws NotFoundException if pattern is not found
*/
private static int[] findGuardPattern(BitArray row,
int rowOffset,
boolean whiteFirst,
int[] pattern,
int[] counters) throws NotFoundException {
int width = row.getSize();
rowOffset = whiteFirst ? row.getNextUnset(rowOffset) : row.getNextSet(rowOffset);
int counterPosition = 0;
int patternStart = rowOffset;
int patternLength = pattern.length;
boolean isWhite = whiteFirst;
for (int x = rowOffset; x < width; x++) {
if (row.get(x) != isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition == patternLength - 1) {
if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE) {
return new int[]{patternStart, x};
}
patternStart += counters[0] + counters[1];
System.arraycopy(counters, 2, counters, 0, counterPosition - 1);
counters[counterPosition - 1] = 0;
counters[counterPosition] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw NotFoundException.getNotFoundInstance();
}
private 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 < 5 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x != 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 5) {
throw NotFoundException.getNotFoundInstance();
}
int checkDigit = determineCheckDigit(lgPatternFound);
if (extensionChecksum(resultString.toString()) != checkDigit) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
private static int getNextSecondBar(BitArray row, int initialPos) {
int currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
private 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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
checkParity |= 1 << (1 - x);
}
if (x != 1) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 2) {
throw NotFoundException.getNotFoundInstance();
}
if (Integer.parseInt(resultString.toString()) % 4 != checkParity) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
checkParity |= 1 << (1 - x);
}
if (x != 1) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 2) {
throw NotFoundException.getNotFoundInstance();
}
if (Integer.parseInt(resultString.toString()) % 4 != checkParity) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
private static int getNextSecondBar(BitArray row, int initialPos){
int currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
private 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 < 5 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x != 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 5) {
throw NotFoundException.getNotFoundInstance();
}
int checkDigit = determineCheckDigit(lgPatternFound);
if (extensionChecksum(resultString.toString()) != checkDigit) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
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 < 5 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x != 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 5) {
throw NotFoundException.getNotFoundInstance();
}
int checkDigit = determineCheckDigit(lgPatternFound);
if (extensionChecksum(resultString.toString()) != checkDigit) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
checkParity |= 1 << (1 - x);
}
if (x != 1) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 2) {
throw NotFoundException.getNotFoundInstance();
}
if (Integer.parseInt(resultString.toString()) % 4 != checkParity) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
private 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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
checkParity |= 1 << (1 - x);
}
if (x != 1) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 2) {
throw NotFoundException.getNotFoundInstance();
}
if (Integer.parseInt(resultString.toString()) % 4 != checkParity) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
/**
* @param row row of black/white values to search
* @param rowOffset position to start search
* @param whiteFirst if true, indicates that the pattern specifies white/black/white/...
* pixel counts, otherwise, it is interpreted as black/white/black/...
* @param pattern pattern of counts of number of black and white pixels that are being
* searched for as a pattern
* @param counters array of counters, as long as pattern, to re-use
* @return start/end horizontal offset of guard pattern, as an array of two ints
* @throws NotFoundException if pattern is not found
*/
private static int[] findGuardPattern(BitArray row,
int rowOffset,
boolean whiteFirst,
int[] pattern,
int[] counters) throws NotFoundException {
int width = row.getSize();
rowOffset = whiteFirst ? row.getNextUnset(rowOffset) : row.getNextSet(rowOffset);
int counterPosition = 0;
int patternStart = rowOffset;
int patternLength = pattern.length;
boolean isWhite = whiteFirst;
for (int x = rowOffset; x < width; x++) {
if (row.get(x) ^ isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition == patternLength - 1) {
if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE) {
return new int[]{patternStart, x};
}
patternStart += counters[0] + counters[1];
System.arraycopy(counters, 2, counters, 0, patternLength - 2);
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw NotFoundException.getNotFoundInstance();
}
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 < 5 && rowOffset < end; x++) {
int bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS);
resultString.append((char) ('0' + bestMatch % 10));
for (int counter : counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x != 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length() != 5) {
throw NotFoundException.getNotFoundInstance();
}
int checkDigit = determineCheckDigit(lgPatternFound);
if (extensionChecksum(resultString.toString()) != checkDigit) {
throw NotFoundException.getNotFoundInstance();
}
return rowOffset;
}
private FinderPattern parseFoundFinderPattern(BitArray row, int rowNumber, boolean oddPattern) {
// Actually we found elements 2-5.
int firstCounter;
int start;
int end;
if (oddPattern) {
// If pattern number is odd, we need to locate element 1 *before* the current block.
int firstElementStart = this.startEnd[0] - 1;
// Locate element 1
while (firstElementStart >= 0 && !row.get(firstElementStart)) {
firstElementStart--;
}
firstElementStart++;
firstCounter = this.startEnd[0] - firstElementStart;
start = firstElementStart;
end = this.startEnd[1];
} else {
// If pattern number is even, the pattern is reversed, so we need to locate element 1 *after* the current block.
start = this.startEnd[0];
end = row.getNextUnset(this.startEnd[1] + 1);
firstCounter = end - this.startEnd[1];
}
// Make 'counters' hold 1-4
int [] counters = this.getDecodeFinderCounters();
System.arraycopy(counters, 0, counters, 1, counters.length - 1);
counters[0] = firstCounter;
int value;
try {
value = parseFinderValue(counters, FINDER_PATTERNS);
} catch (NotFoundException ignored) {
return null;
}
return new FinderPattern(value, new int[] {start, end}, start, end, rowNumber);
}