ReactNativeAlternateIcons.m

#import "ReactNativeAlternateIcons.h"
#import <React/RCTLog.h>
#import <React/RCTClipboard.h>
#import <UIKit/UIKit.h>

@implementation ReactNativeAlternateIcons

#define SYSTEM_VERSION_EQUAL_TO(v)                  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedSame)
#define SYSTEM_VERSION_GREATER_THAN(v)              ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedDescending)
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v)                 ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v)     ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedDescending)

RCT_EXPORT_MODULE();

RCT_EXPORT_METHOD(setIconName:(NSString *)name){
    if( SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.3") ){
        [[UIApplication sharedApplication] setAlternateIconName:name completionHandler:^(NSError * _Nullable error) {
            if( error != nil ){
                NSLog(@"Error: %@", error.description );
            }
        }];
    }
}

RCT_EXPORT_METHOD(reset){
    if( SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.3") ){
        [[UIApplication sharedApplication] setAlternateIconName:nil completionHandler:^(NSError * _Nullable error) {
            if( error != nil ){
                NSLog(@"Error: %@", error.description );
            }
        }];
    }
}

RCT_EXPORT_METHOD(getIconName:(RCTResponseSenderBlock) callback ){
    NSString *name = @"default";
    NSDictionary *results;
    
    if( SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.3") ){
        if( [[UIApplication sharedApplication] supportsAlternateIcons ] ){
            name = [[UIApplication sharedApplication] alternateIconName];
            if( name == nil ){
                name = @"default";
            }
        }
    }
    
    results = @{
                @"iconName":name
                };
    callback(@[results]);
}

RCT_EXPORT_METHOD(supportDevice:(RCTResponseSenderBlock) callback){
    NSDictionary *results = @{
                              @"supported":@NO
                              };
    
    if( SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.3") ){
        if( [[UIApplication sharedApplication] supportsAlternateIcons ] ){
            results = @{
                        @"supported":@YES
                        };
        }else{
            results = @{
                        @"supported":@NO
                        };
        }
    }
    
    callback(@[results]);
}

@end