Extends [UIImage imageNamed:] method to consider also -568h@2x suffices of images targeted for Retina 4" devices. #iOS #objective-c #retina #ui #utility

UIImage+Retina4.h

#import <UIKit/UIKit.h>

@interface UIImage (Retina4)

+ (UIImage *)imageNamedRetina4:(NSString *)imageName;

@end

UIImage+Retina4.m

#import "UIImage+Retina4.h"

@implementation UIImage (Retina4)

+ (UIImage *)imageNamedRetina4:(NSString *)imageName {
    if (![[UIScreen mainScreen] isRetina4]) return [UIImage imageNamed:imageName];
    
    NSMutableString *imageNameMutable = [imageName mutableCopy];
    NSRange retinaAtSymbol = [imageName rangeOfString:@"@"];
    
    if (retinaAtSymbol.location != NSNotFound) {
        NSLog(@"Warning: UIImage might misconfigure scale property if you include @2x in the image name!");
        [imageNameMutable insertString:@"-568h" atIndex:retinaAtSymbol.location];
    } else {
        NSRange dot = [imageName rangeOfString:@"."];
        if (dot.location != NSNotFound) {
            [imageNameMutable insertString:@"-568h" atIndex:dot.location];
        } else {
            [imageNameMutable appendString:@"-568h"];
        }
    }
    
    UIImage* image = [UIImage imageNamed:imageNameMutable];
    if (image) {
        return image;
    } else {
        return [UIImage imageNamed:imageName];
    }
}

@end

UIScreen+Retina4.h

#import <UIKit/UIKit.h>

@interface UIScreen (Retina4)

-(BOOL)isRetina4;

@end

UIScreen+Retina4.m

#import "UIScreen+Retina4.h"

@implementation UIScreen (Retina4)

-(BOOL)isRetina4
{
    return (self.scale == 2.f && self.bounds.size.height == 568.0f);
}

@end