A Masonry Extension supports iOS 11 safeAreaLayoutGuide, @see https://github.com/SnapKit/Masonry/pull/473

Masonry+M9Ext.h

//
//  Masonry+M9Ext.h
//  M9Dev
//
//  Created by MingLQ on 2017-04-05.
//  Copyright © 2017 MingLQ <[email protected]>. Released under the MIT license.
//

#import <Masonry/Masonry.h>

NS_ASSUME_NONNULL_BEGIN

/**
 @see https://github.com/SnapKit/Masonry/pull/473
 */
@interface MAS_VIEW (M9Ext)

@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuide;

@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideLeading;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideTrailing;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideLeft;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideRight;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideTop;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideBottom;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideWidth;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideHeight;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideCenterX;
@property (nonatomic, readonly, nullable) MASViewAttribute *m9_safeAreaLayoutGuideCenterY;

@end

NS_ASSUME_NONNULL_END

Masonry+M9Ext.m

//
//  Masonry+M9Ext.m
//  M9Dev
//
//  Created by MingLQ on 2017-04-05.
//  Copyright © 2017 MingLQ <[email protected]>. Released under the MIT license.
//

#import <objc/runtime.h>

#import "Masonry+M9Ext.h"

NS_ASSUME_NONNULL_BEGIN

static inline void m9_swizzleSelector(Class theClass, SEL originalSelector, SEL swizzledSelector) {
    Method originalMethod = class_getInstanceMethod(theClass, originalSelector);
    Method swizzledMethod = class_getInstanceMethod(theClass, swizzledSelector);
    method_exchangeImplementations(originalMethod, swizzledMethod);
}

#pragma mark -

@interface MASViewConstraint (M9Ext)

@property (nonatomic, strong, readwrite) MASViewAttribute *secondViewAttribute;

@end

@implementation MASViewConstraint (M9Ext)

+ (void)load {
    m9_swizzleSelector([self class],
                       @selector(setSecondViewAttribute:),
                       @selector(m9_setSecondViewAttribute:));
}

@dynamic secondViewAttribute;
- (void)m9_setSecondViewAttribute:(id)secondViewAttribute {
    if ([secondViewAttribute isKindOfClass:MASViewAttribute.class]) {
        MASViewAttribute *attr = secondViewAttribute;
        if (attr.layoutAttribute == NSLayoutAttributeNotAnAttribute) {
            secondViewAttribute = [[MASViewAttribute alloc] initWithView:attr.view item:attr.item layoutAttribute:self.firstViewAttribute.layoutAttribute];;
        }
    }
    [self m9_setSecondViewAttribute:secondViewAttribute];
}

@end

#pragma mark -

@implementation MAS_VIEW (M9Ext)

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuide {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeNotAnAttribute];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideLeading {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeLeading];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideTrailing {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeTrailing];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideLeft {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeLeft];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideRight {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeRight];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideTop {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeTop];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideBottom {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeBottom];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideWidth {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeWidth];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideHeight {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeHeight];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideCenterX {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeCenterX];
    }
#endif
    return nil;
}

- (nullable MASViewAttribute *)m9_safeAreaLayoutGuideCenterY {
#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 110000)
    if (@available(iOS 11.0, *)) {
        return [[MASViewAttribute alloc] initWithView:self item:self.safeAreaLayoutGuide layoutAttribute:NSLayoutAttributeCenterY];
    }
#endif
    return nil;
}

@end

NS_ASSUME_NONNULL_END