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- /*
- * Copyright 2012 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 "ZXByteArray.h"
- #import "ZXQRCodeDataBlock.h"
- #import "ZXQRCodeErrorCorrectionLevel.h"
- #import "ZXQRCodeVersion.h"
-
- @implementation ZXQRCodeDataBlock
-
- - (id)initWithNumDataCodewords:(int)numDataCodewords codewords:(ZXByteArray *)codewords {
- if (self = [super init]) {
- _numDataCodewords = numDataCodewords;
- _codewords = codewords;
- }
-
- return self;
- }
-
- + (NSArray *)dataBlocks:(ZXByteArray *)rawCodewords version:(ZXQRCodeVersion *)version ecLevel:(ZXQRCodeErrorCorrectionLevel *)ecLevel {
- if (rawCodewords.length != version.totalCodewords) {
- [NSException raise:NSInvalidArgumentException format:@"Invalid codewords count"];
- }
-
- // Figure out the number and size of data blocks used by this version and
- // error correction level
- ZXQRCodeECBlocks *ecBlocks = [version ecBlocksForLevel:ecLevel];
-
- // First count the total number of data blocks
- int totalBlocks = 0;
- NSArray *ecBlockArray = ecBlocks.ecBlocks;
- for (ZXQRCodeECB *ecBlock in ecBlockArray) {
- totalBlocks += ecBlock.count;
- }
-
- // Now establish DataBlocks of the appropriate size and number of data codewords
- NSMutableArray *result = [NSMutableArray arrayWithCapacity:totalBlocks];
- for (ZXQRCodeECB *ecBlock in ecBlockArray) {
- for (int i = 0; i < ecBlock.count; i++) {
- int numDataCodewords = ecBlock.dataCodewords;
- int numBlockCodewords = ecBlocks.ecCodewordsPerBlock + numDataCodewords;
- [result addObject:[[ZXQRCodeDataBlock alloc] initWithNumDataCodewords:numDataCodewords codewords:[[ZXByteArray alloc] initWithLength:numBlockCodewords]]];
- }
- }
-
- // All blocks have the same amount of data, except that the last n
- // (where n may be 0) have 1 more byte. Figure out where these start.
- int shorterBlocksTotalCodewords = [(ZXQRCodeDataBlock *)result[0] codewords].length;
- int longerBlocksStartAt = (int)[result count] - 1;
- while (longerBlocksStartAt >= 0) {
- int numCodewords = [(ZXQRCodeDataBlock *)result[longerBlocksStartAt] codewords].length;
- if (numCodewords == shorterBlocksTotalCodewords) {
- break;
- }
- longerBlocksStartAt--;
- }
- longerBlocksStartAt++;
-
- int shorterBlocksNumDataCodewords = shorterBlocksTotalCodewords - ecBlocks.ecCodewordsPerBlock;
- // The last elements of result may be 1 element longer;
- // first fill out as many elements as all of them have
- int rawCodewordsOffset = 0;
- int numResultBlocks = (int)[result count];
- for (int i = 0; i < shorterBlocksNumDataCodewords; i++) {
- for (int j = 0; j < numResultBlocks; j++) {
- [(ZXQRCodeDataBlock *)result[j] codewords].array[i] = rawCodewords.array[rawCodewordsOffset++];
- }
- }
- // Fill out the last data block in the longer ones
- for (int j = longerBlocksStartAt; j < numResultBlocks; j++) {
- [(ZXQRCodeDataBlock *)result[j] codewords].array[shorterBlocksNumDataCodewords] = rawCodewords.array[rawCodewordsOffset++];
- }
- // Now add in error correction blocks
- int max = (int)[(ZXQRCodeDataBlock *)result[0] codewords].length;
- for (int i = shorterBlocksNumDataCodewords; i < max; i++) {
- for (int j = 0; j < numResultBlocks; j++) {
- int iOffset = j < longerBlocksStartAt ? i : i + 1;
- [(ZXQRCodeDataBlock *)result[j] codewords].array[iOffset] = rawCodewords.array[rawCodewordsOffset++];
- }
- }
-
- return result;
- }
-
- @end
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