/*
|
* Copyright 2013 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.
|
*/
|
|
#import "ZXDataMatrixEdifactEncoder.h"
|
#import "ZXDataMatrixEncoderContext.h"
|
#import "ZXDataMatrixHighLevelEncoder.h"
|
#import "ZXDataMatrixSymbolInfo.h"
|
|
@implementation ZXDataMatrixEdifactEncoder
|
|
- (int)encodingMode {
|
return [ZXDataMatrixHighLevelEncoder edifactEncodation];
|
}
|
|
- (void)encode:(ZXDataMatrixEncoderContext *)context {
|
//step F
|
NSMutableString *buffer = [NSMutableString string];
|
while ([context hasMoreCharacters]) {
|
unichar c = [context currentChar];
|
[self encodeChar:c buffer:buffer];
|
context.pos++;
|
|
NSUInteger count = buffer.length;
|
if (count >= 4) {
|
[context writeCodewords:[self encodeToCodewords:buffer startpos:0]];
|
[buffer deleteCharactersInRange:NSMakeRange(0, 4)];
|
|
int newMode = [ZXDataMatrixHighLevelEncoder lookAheadTest:context.message startpos:context.pos currentMode:[self encodingMode]];
|
if (newMode != [self encodingMode]) {
|
[context signalEncoderChange:[ZXDataMatrixHighLevelEncoder asciiEncodation]];
|
break;
|
}
|
}
|
}
|
[buffer appendFormat:@"%C", (unichar) 31]; //Unlatch
|
[self handleEOD:context buffer:buffer];
|
}
|
|
/**
|
* Handle "end of data" situations
|
*
|
* @param context the encoder context
|
* @param buffer the buffer with the remaining encoded characters
|
*/
|
- (void)handleEOD:(ZXDataMatrixEncoderContext *)context buffer:(NSMutableString *)buffer {
|
@try {
|
NSUInteger count = buffer.length;
|
if (count == 0) {
|
return; //Already finished
|
}
|
if (count == 1) {
|
//Only an unlatch at the end
|
[context updateSymbolInfo];
|
int available = context.symbolInfo.dataCapacity - context.codewordCount;
|
int remaining = [context remainingCharacters];
|
if (remaining == 0 && available <= 2) {
|
return; //No unlatch
|
}
|
}
|
|
if (count > 4) {
|
@throw [NSException exceptionWithName:@"IllegalStateException"
|
reason:@"Count must not exceed 4"
|
userInfo:nil];
|
}
|
int restChars = (int)count - 1;
|
NSString *encoded = [self encodeToCodewords:buffer startpos:0];
|
BOOL endOfSymbolReached = ![context hasMoreCharacters];
|
BOOL restInAscii = endOfSymbolReached && restChars <= 2;
|
|
if (restChars <= 2) {
|
[context updateSymbolInfoWithLength:context.codewordCount + restChars];
|
int available = context.symbolInfo.dataCapacity - context.codewordCount;
|
if (available >= 3) {
|
restInAscii = NO;
|
[context updateSymbolInfoWithLength:context.codewordCount + (int)encoded.length];
|
//available = context.symbolInfo.dataCapacity - context.codewordCount;
|
}
|
}
|
|
if (restInAscii) {
|
[context resetSymbolInfo];
|
context.pos -= restChars;
|
} else {
|
[context writeCodewords:encoded];
|
}
|
} @finally {
|
[context signalEncoderChange:[ZXDataMatrixHighLevelEncoder asciiEncodation]];
|
}
|
}
|
|
- (void)encodeChar:(unichar)c buffer:(NSMutableString *)sb {
|
if (c >= ' ' && c <= '?') {
|
[sb appendFormat:@"%C", c];
|
} else if (c >= '@' && c <= '^') {
|
[sb appendFormat:@"%C", (unichar) (c - 64)];
|
} else {
|
[ZXDataMatrixHighLevelEncoder illegalCharacter:c];
|
}
|
}
|
|
- (NSString *)encodeToCodewords:(NSMutableString *)sb startpos:(int)startPos {
|
int len = (int)sb.length - startPos;
|
if (len == 0) {
|
@throw [NSException exceptionWithName:@"IllegalStateException"
|
reason:@"Buffer must not be empty"
|
userInfo:nil];
|
}
|
unichar c1 = [sb characterAtIndex:startPos];
|
unichar c2 = len >= 2 ? [sb characterAtIndex:startPos + 1] : 0;
|
unichar c3 = len >= 3 ? [sb characterAtIndex:startPos + 2] : 0;
|
unichar c4 = len >= 4 ? [sb characterAtIndex:startPos + 3] : 0;
|
|
int v = (c1 << 18) + (c2 << 12) + (c3 << 6) + c4;
|
unichar cw1 = (unichar) ((v >> 16) & 255);
|
unichar cw2 = (unichar) ((v >> 8) & 255);
|
unichar cw3 = (unichar) (v & 255);
|
NSMutableString *res = [NSMutableString stringWithCapacity:3];
|
[res appendFormat:@"%C", cw1];
|
if (len >= 2) {
|
[res appendFormat:@"%C", cw2];
|
}
|
if (len >= 3) {
|
[res appendFormat:@"%C", cw3];
|
}
|
return [NSString stringWithString:res];
|
}
|
|
@end
|
