SDWebImage/SDWebImage/NSData+ImageContentType.m

49 lines
1.2 KiB
Objective-C

/*
* This file is part of the SDWebImage package.
* (c) Olivier Poitrey <rs@dailymotion.com>
* (c) Fabrice Aneche
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
#import "NSData+ImageContentType.h"
@implementation NSData (ImageContentType)
+ (nullable NSString *)sd_contentTypeForImageData:(nullable NSData *)data {
if (!data) {
return nil;
}
uint8_t c;
[data getBytes:&c length:1];
switch (c) {
case 0xFF:
return @"image/jpeg";
case 0x89:
return @"image/png";
case 0x47:
return @"image/gif";
case 0x49:
case 0x4D:
return @"image/tiff";
case 0x52:
// R as RIFF for WEBP
if (data.length < 12) {
return nil;
}
NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
if ([testString hasPrefix:@"RIFF"] && [testString hasSuffix:@"WEBP"]) {
return @"image/webp";
}
return nil;
}
return nil;
}
@end