Block based interface to UIKeyCommand

UIResponder+FTAdditions.h

//
//  UIResponder+FTAdditions.h
//  Streets
//
//  Created by Ortwin Gentz on 09.05.16.
//  Copyright © 2016 FutureTap. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface FTKeyCommand : NSObject <NSObject>
+ (instancetype)keyCommandWithInput:(NSString *)input modifierFlags:(UIKeyModifierFlags)modifierFlags discoverabilityTitle:(NSString *)discoverabilityTitle block:(void(^)())block;
@property (nonatomic) NSString *input;
@property (nonatomic) UIKeyModifierFlags modifierFlags;
@property (nonatomic) NSString *discoverabilityTitle;
@property (nonatomic) void (^block)();
@end


@interface UIResponder (FTAdditions)
@property (nonatomic) NSArray *ftKeyCommands;
@end

UIResponder+FTAdditions.m

//
//  UIResponder+FTAdditions.m
//  Streets
//
//  Created by Ortwin Gentz on 09.05.16.
//  Copyright © 2016 FutureTap. All rights reserved.
//

#import <objc/runtime.h>

#import "UIResponder+FTAdditions.h"
#import "MethodSwizzling.h"
#import "NSArray+Additions.h"
#import "UIDevice+Additions.h"

@implementation FTKeyCommand

+ (instancetype)keyCommandWithInput:(NSString *)input modifierFlags:(UIKeyModifierFlags)modifierFlags discoverabilityTitle:(NSString *)discoverabilityTitle block:(void(^)())block {
    FTKeyCommand *keyCommand = [[self alloc] init];
    keyCommand.input = input;
    keyCommand.modifierFlags = modifierFlags;
    keyCommand.discoverabilityTitle = discoverabilityTitle;
    keyCommand.block = block;
    return keyCommand;
}

- (BOOL)isEqual:(FTKeyCommand*)keyCommand {
    return [self.input isEqual:keyCommand.input] && self.modifierFlags == keyCommand.modifierFlags;
}

@end

@implementation UIResponder (FTAdditions)

+ (void)load {
    Swizzle(self, @selector(canBecomeFirstResponder), @selector(myCanBecomeFirstResponder));
    Swizzle(self, @selector(keyCommands), @selector(myKeyCommands));
}

static char ftKeyCommandsKey;

- (void)setFtKeyCommands:(NSArray *)ftKeyCommands {
    objc_setAssociatedObject(self, &ftKeyCommandsKey, ftKeyCommands, OBJC_ASSOCIATION_RETAIN);
}

- (NSArray*)ftKeyCommands {
    return objc_getAssociatedObject(self, &ftKeyCommandsKey);
}

- (NSArray*)myKeyCommands {
    if (self.ftKeyCommands) {
        NSArray *keyCommands = [self.ftKeyCommands mapObjectsUsingBlock:^id(FTKeyCommand *keyCommand, NSUInteger idx) {
            if ([UIKeyCommand respondsToSelector:@selector(keyCommandWithInput:modifierFlags:action:discoverabilityTitle:)]) {
                return [UIKeyCommand keyCommandWithInput:keyCommand.input modifierFlags:keyCommand.modifierFlags action:@selector(ftPerformKeyCommand:)];
            }
            return [UIKeyCommand keyCommandWithInput:keyCommand.input modifierFlags:keyCommand.modifierFlags action:@selector(ftPerformKeyCommand:)];
        }];
        return keyCommands;
    } else {
        return [self myKeyCommands];
    }
}

- (void)ftPerformKeyCommand:(UIKeyCommand*)keyCommand {
    FTKeyCommand *ftKkeyCommand = [self.ftKeyCommands selectFirstObjectUsingBlock:^BOOL(FTKeyCommand *testKeyCommand) {
        return [testKeyCommand isEqual:keyCommand];
    }];
    if (ftKkeyCommand) {
        ftKkeyCommand.block();
    }
}

- (BOOL)myCanBecomeFirstResponder {
    return self.ftKeyCommands.count ?: [self myCanBecomeFirstResponder];
}
@end