/*
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* Copyright 2013 9 authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#import "ZXDataMatrixC40Encoder.h"
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#import "ZXDataMatrixEncoderContext.h"
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#import "ZXDataMatrixHighLevelEncoder.h"
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#import "ZXDataMatrixSymbolInfo.h"
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@implementation ZXDataMatrixC40Encoder
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- (int)encodingMode {
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return [ZXDataMatrixHighLevelEncoder c40Encodation];
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}
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- (void)encode:(ZXDataMatrixEncoderContext *)context {
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//step C
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NSMutableString *buffer = [NSMutableString string];
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while ([context hasMoreCharacters]) {
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unichar c = [context currentChar];
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context.pos++;
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int lastCharSize = [self encodeChar:c buffer:buffer];
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int unwritten = ((int)buffer.length / 3) * 2;
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int curCodewordCount = context.codewordCount + unwritten;
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[context updateSymbolInfoWithLength:curCodewordCount];
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int available = context.symbolInfo.dataCapacity - curCodewordCount;
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if (![context hasMoreCharacters]) {
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//Avoid having a single C40 value in the last triplet
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NSMutableString *removed = [NSMutableString string];
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if ((buffer.length % 3) == 2) {
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if (available < 2 || available > 2) {
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lastCharSize = [self backtrackOneCharacter:context buffer:buffer removed:removed lastCharSize:lastCharSize];
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}
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}
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while ((buffer.length % 3) == 1
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&& ((lastCharSize <= 3 && available != 1) || lastCharSize > 3)) {
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lastCharSize = [self backtrackOneCharacter:context buffer:buffer removed:removed lastCharSize:lastCharSize];
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}
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break;
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}
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NSUInteger count = buffer.length;
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if ((count % 3) == 0) {
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int newMode = [ZXDataMatrixHighLevelEncoder lookAheadTest:context.message startpos:context.pos currentMode:[self encodingMode]];
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if (newMode != [self encodingMode]) {
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[context signalEncoderChange:newMode];
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break;
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}
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}
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}
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[self handleEOD:context buffer:buffer];
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}
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- (int)backtrackOneCharacter:(ZXDataMatrixEncoderContext *)context buffer:(NSMutableString *)buffer
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removed:(NSMutableString *)removed lastCharSize:(int)lastCharSize {
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NSUInteger count = buffer.length;
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[buffer deleteCharactersInRange:NSMakeRange(count - lastCharSize, lastCharSize)];
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context.pos--;
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unichar c = context.currentChar;
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lastCharSize = [self encodeChar:c buffer:removed];
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[context resetSymbolInfo]; //Deal with possible reduction in symbol size
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return lastCharSize;
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}
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- (void)writeNextTriplet:(ZXDataMatrixEncoderContext *)context buffer:(NSMutableString *)buffer {
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[context writeCodewords:[self encodeToCodewords:buffer startpos:0]];
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[buffer deleteCharactersInRange:NSMakeRange(0, 3)];
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}
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/**
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* Handle "end of data" situations
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*/
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- (void)handleEOD:(ZXDataMatrixEncoderContext *)context buffer:(NSMutableString *)buffer {
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int unwritten = ((int)buffer.length / 3) * 2;
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int rest = buffer.length % 3;
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int curCodewordCount = context.codewordCount + unwritten;
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[context updateSymbolInfoWithLength:curCodewordCount];
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int available = context.symbolInfo.dataCapacity - curCodewordCount;
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if (rest == 2) {
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[buffer appendString:@"\0"]; //Shift 1
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while (buffer.length >= 3) {
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[self writeNextTriplet:context buffer:buffer];
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}
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if ([context hasMoreCharacters]) {
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[context writeCodeword:[ZXDataMatrixHighLevelEncoder c40Unlatch]];
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}
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} else if (available == 1 && rest == 1) {
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while (buffer.length >= 3) {
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[self writeNextTriplet:context buffer:buffer];
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}
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if ([context hasMoreCharacters]) {
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[context writeCodeword:[ZXDataMatrixHighLevelEncoder c40Unlatch]];
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}
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// else no latch
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context.pos--;
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} else if (rest == 0) {
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while (buffer.length >= 3) {
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[self writeNextTriplet:context buffer:buffer];
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}
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if (available > 0 || [context hasMoreCharacters]) {
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[context writeCodeword:[ZXDataMatrixHighLevelEncoder c40Unlatch]];
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}
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} else {
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@throw [NSException exceptionWithName:@"IllegalStateException"
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reason:@"Unexpected case. Please report!"
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userInfo:nil];
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}
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[context signalEncoderChange:[ZXDataMatrixHighLevelEncoder asciiEncodation]];
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}
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- (int)encodeChar:(unichar)c buffer:(NSMutableString *)sb {
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if (c == ' ') {
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[sb appendString:@"\3"];
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return 1;
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} else if (c >= '0' && c <= '9') {
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[sb appendFormat:@"%C", (unichar) (c - 48 + 4)];
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return 1;
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} else if (c >= 'A' && c <= 'Z') {
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[sb appendFormat:@"%C", (unichar) (c - 65 + 14)];
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return 1;
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} else if (c >= '\0' && c <= (unichar)0x001f) {
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[sb appendString:@"\0"]; //Shift 1 Set
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[sb appendFormat:@"%C", c];
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return 2;
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} else if (c >= '!' && c <= '/') {
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[sb appendString:@"\1"]; //Shift 2 Set
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[sb appendFormat:@"%C", (unichar) (c - 33)];
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return 2;
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} else if (c >= ':' && c <= '@') {
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[sb appendString:@"\1"]; //Shift 2 Set
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[sb appendFormat:@"%C", (unichar) (c - 58 + 15)];
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return 2;
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} else if (c >= '[' && c <= '_') {
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[sb appendString:@"\1"]; //Shift 2 Set
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[sb appendFormat:@"%C", (unichar) (c - 91 + 22)];
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return 2;
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} else if (c >= '\u0060' && c <= (unichar)0x007f) {
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[sb appendString:@"\2"]; //Shift 3 Set
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[sb appendFormat:@"%C", (unichar) (c - 96)];
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return 2;
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} else if (c >= (unichar)0x0080) {
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[sb appendFormat:@"\1%C", (unichar)0x001e]; //Shift 2, Upper Shift
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int len = 2;
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len += [self encodeChar:(unichar) (c - 128) buffer:sb];
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return len;
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} else {
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@throw [NSException exceptionWithName:@"IllegalStateException"
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reason:[NSString stringWithFormat:@"Illegal character: %C", c]
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userInfo:nil];
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}
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}
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- (NSString *)encodeToCodewords:(NSString *)sb startpos:(int)startPos {
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unichar c1 = [sb characterAtIndex:startPos];
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unichar c2 = [sb characterAtIndex:startPos + 1];
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unichar c3 = [sb characterAtIndex:startPos + 2];
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int v = (1600 * c1) + (40 * c2) + c3 + 1;
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unichar cw1 = (unichar) (v / 256);
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unichar cw2 = (unichar) (v % 256);
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return [NSString stringWithFormat:@"%C%C", cw1, cw2];
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}
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@end
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