Swizzle using block (#71)

* swizzle-with-block

* Fix UILabel

* Returning IMP from method_getImplementation and add UILabelVC

* Remove NSObject+DarkModeKit

FluentDarkModeKit.xcodeproj/project.pbxproj

@@ -7,8 +7,6 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
-		8C071AEC23683BF5001AB7B2 /* NSObject+DarkModeKit.h in Headers */ = {isa = PBXBuildFile; fileRef = 8C071AEA23683BF5001AB7B2 /* NSObject+DarkModeKit.h */; settings = {ATTRIBUTES = (Public, ); }; };
-		8C071AED23683BF5001AB7B2 /* NSObject+DarkModeKit.m in Sources */ = {isa = PBXBuildFile; fileRef = 8C071AEB23683BF5001AB7B2 /* NSObject+DarkModeKit.m */; };
 		8C1915D82361EFDB004A606A /* FluentDarkModeKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 8C1915CE2361EFDB004A606A /* FluentDarkModeKit.framework */; };
 		8C1915DD2361EFDB004A606A /* DarkModeKitTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8C1915DC2361EFDB004A606A /* DarkModeKitTests.swift */; };
 		8C63F64323A36B2700D93CF4 /* UIButtonVC.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8C63F64123A36B0900D93CF4 /* UIButtonVC.swift */; };
@@ -56,6 +54,7 @@
 		8CDA62A52366DAA9004895B5 /* DMDynamicColor.h in Headers */ = {isa = PBXBuildFile; fileRef = 8CDA628B2366DAA9004895B5 /* DMDynamicColor.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		8CE066CF239E5582002CE16D /* UIColor+DarkModeKit.m in Sources */ = {isa = PBXBuildFile; fileRef = 8CC8D86C2398E4EC0043276A /* UIColor+DarkModeKit.m */; };
 		8CE066D0239E5586002CE16D /* UIImage+DarkModeKit.m in Sources */ = {isa = PBXBuildFile; fileRef = 8CC8D8722398E7A30043276A /* UIImage+DarkModeKit.m */; };
+		EA7316F1248F5055009AE037 /* UILabelVC.swift in Sources */ = {isa = PBXBuildFile; fileRef = EA7316EF248F5050009AE037 /* UILabelVC.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -97,8 +96,6 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
-		8C071AEA23683BF5001AB7B2 /* NSObject+DarkModeKit.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSObject+DarkModeKit.h"; sourceTree = "<group>"; };
-		8C071AEB23683BF5001AB7B2 /* NSObject+DarkModeKit.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSObject+DarkModeKit.m"; sourceTree = "<group>"; };
 		8C1915CE2361EFDB004A606A /* FluentDarkModeKit.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FluentDarkModeKit.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		8C1915D22361EFDB004A606A /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		8C1915D72361EFDB004A606A /* FluentDarkModeKitTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = FluentDarkModeKitTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -151,6 +148,7 @@
 		8CDA62892366DAA9004895B5 /* DMDynamicImage.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = DMDynamicImage.m; sourceTree = "<group>"; };
 		8CDA628A2366DAA9004895B5 /* DarkModeManager.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DarkModeManager.swift; sourceTree = "<group>"; };
 		8CDA628B2366DAA9004895B5 /* DMDynamicColor.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DMDynamicColor.h; sourceTree = "<group>"; };
+		EA7316EF248F5050009AE037 /* UILabelVC.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UILabelVC.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -216,8 +214,6 @@
 				8CDA62892366DAA9004895B5 /* DMDynamicImage.m */,
 				8CDA62712366DAA9004895B5 /* DMTraitCollection.h */,
 				8CDA62722366DAA9004895B5 /* DMTraitCollection.m */,
-				8C071AEA23683BF5001AB7B2 /* NSObject+DarkModeKit.h */,
-				8C071AEB23683BF5001AB7B2 /* NSObject+DarkModeKit.m */,
 				8CC8D86F2398E7520043276A /* DMNamespace.h */,
 				8CC8D86B2398E4EC0043276A /* UIColor+DarkModeKit.h */,
 				8CC8D86C2398E4EC0043276A /* UIColor+DarkModeKit.m */,
@@ -291,6 +287,7 @@
 				8C7B250A23A22A70002E2558 /* UIActivityIndicatorViewVC.swift */,
 				8C63F64123A36B0900D93CF4 /* UIButtonVC.swift */,
 				8C63F64423A374CF00D93CF4 /* UIPageControlVC.swift */,
+				EA7316EF248F5050009AE037 /* UILabelVC.swift */,
 				8CAFD9DD23715FAB001A63B8 /* Assets.xcassets */,
 				8CAFD9DF23715FAB001A63B8 /* LaunchScreen.storyboard */,
 				8CAFD9E223715FAB001A63B8 /* Info.plist */,
@@ -338,7 +335,6 @@
 			files = (
 				8CC8D86D2398E4EC0043276A /* UIColor+DarkModeKit.h in Headers */,
 				8CC8D8702398E7520043276A /* DMNamespace.h in Headers */,
-				8C071AEC23683BF5001AB7B2 /* NSObject+DarkModeKit.h in Headers */,
 				8CDA628D2366DAA9004895B5 /* DMTraitCollection.h in Headers */,
 				8CDA628C2366DAA9004895B5 /* FluentDarkModeKit.h in Headers */,
 				8CB63E41238551F3008ABCE2 /* UIView+DarkModeKit.h in Headers */,
@@ -551,7 +547,6 @@
 				8CDA629C2366DAA9004895B5 /* UINavigationBar+DarkModeKit.swift in Sources */,
 				8CDA629D2366DAA9004895B5 /* UITabBar+DarkModeKit.swift in Sources */,
 				8CDA62922366DAA9004895B5 /* UIToolbar+DarkModeKit.swift in Sources */,
-				8C071AED23683BF5001AB7B2 /* NSObject+DarkModeKit.m in Sources */,
 				8CDA629A2366DAA9004895B5 /* UIPageControl+DarkModeKit.swift in Sources */,
 				8CDA62932366DAA9004895B5 /* UIButton+DarkModeKit.swift in Sources */,
 				8CDA629B2366DAA9004895B5 /* UITableView+DarkModeKit.swift in Sources */,
@@ -582,6 +577,7 @@
 				8C7B250C23A22A80002E2558 /* UIActivityIndicatorViewVC.swift in Sources */,
 				8CAFD9D923715FAA001A63B8 /* ViewController.swift in Sources */,
 				8C63F64323A36B2700D93CF4 /* UIButtonVC.swift in Sources */,
+				EA7316F1248F5055009AE037 /* UILabelVC.swift in Sources */,
 				8CAFD9ED2371606D001A63B8 /* NavigationController.swift in Sources */,
 				8CAFD9D523715FAA001A63B8 /* AppDelegate.swift in Sources */,
 				8C63F64623A374D300D93CF4 /* UIPageControlVC.swift in Sources */,

Sources/DarkModeCore/DMDynamicImage.m

@@ -5,7 +5,6 @@
 
 #import "DMDynamicImage.h"
 #import "DMTraitCollection.h"
-#import "NSObject+DarkModeKit.h"
 
 @import ObjectiveC;
 

Sources/DarkModeCore/FluentDarkModeKit.h

@@ -6,7 +6,6 @@
 #import <FluentDarkModeKit/DMDynamicColor.h>
 #import <FluentDarkModeKit/DMDynamicImage.h>
 #import <FluentDarkModeKit/DMTraitCollection.h>
-#import <FluentDarkModeKit/NSObject+DarkModeKit.h>
 #import <FluentDarkModeKit/UIColor+DarkModeKit.h>
 #import <FluentDarkModeKit/UIImage+DarkModeKit.h>
 #import <FluentDarkModeKit/UIView+DarkModeKit.h>

Sources/DarkModeCore/NSObject+DarkModeKit.h

@@ -1,19 +0,0 @@
-//
-//  Copyright (c) Microsoft Corporation. All rights reserved.
-//  Licensed under the MIT License.
-//
-
-#import <Foundation/Foundation.h>
-
-NS_ASSUME_NONNULL_BEGIN
-
-@interface NSObject (DarkModeKit)
-
-/// Swizzle two instance methods for class that calls this method.
-///
-/// Return NO if any selector cannot find corresponding method.
-+ (BOOL)dm_swizzleInstanceMethod:(SEL)fromSelector to:(SEL)toSelector;
-
-@end
-
-NS_ASSUME_NONNULL_END

Sources/DarkModeCore/NSObject+DarkModeKit.m

@@ -1,29 +0,0 @@
-//
-//  Copyright (c) Microsoft Corporation. All rights reserved.
-//  Licensed under the MIT License.
-//
-
-#import "NSObject+DarkModeKit.h"
-
-@import ObjectiveC;
-
-@implementation NSObject (DarkModeKit)
-
-+ (BOOL)dm_swizzleInstanceMethod:(SEL)selector1 to:(SEL)selector2 {
-  Method method1 = class_getInstanceMethod(self, selector1);
-  Method method2 = class_getInstanceMethod(self, selector2);
-
-  if (!method1 || !method2) {
-    return NO;
-  }
-
-  if (class_addMethod(self, selector1, method_getImplementation(method2), method_getTypeEncoding(method2))) {
-    class_replaceMethod(self, selector2, method_getImplementation(method1), method_getTypeEncoding(method1));
-  } else {
-    method_exchangeImplementations(method1, method2);
-  }
-
-  return YES;
-}
-
-@end

Sources/DarkModeCore/UIImage+DarkModeKit.h

@@ -14,6 +14,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface UIImage (DarkModeKit)
 
++ (void)dm_swizzleIsEqual;
+
 + (UIImage *)dm_imageWithLightImage:(UIImage *)lightImage darkImage:(UIImage *)darkImage
 NS_SWIFT_UNAVAILABLE("Use init(_:light:dark:) instead.");
 

Sources/DarkModeCore/UIImage+DarkModeKit.m

@@ -5,14 +5,34 @@
 
 #import "UIImage+DarkModeKit.h"
 #import "DMDynamicImage.h"
-#import "NSObject+DarkModeKit.h"
 
 @import ObjectiveC;
 
 @implementation UIImage (DarkModeKit)
 
-+ (void)load {
++ (void)dm_swizzleIsEqual {
-  [UIImage dm_swizzleInstanceMethod:@selector(isEqual:) to:@selector(dm_isEqual:)];
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    SEL selector = @selector(isEqual:);
+    Method method = class_getInstanceMethod(self, selector);
+    if (!method)
+      NSAssert(NO, @"Method not found for [UIImage isEqual:]");
+
+    IMP imp = method_getImplementation(method);
+    class_replaceMethod(self, selector, imp_implementationWithBlock(^BOOL(UIImage *self, UIImage *other) {
+      /// On iOS 13, UIImage `isEqual:` somehow changes internally and doesn't work for `NSProxy`,
+      /// here we forward the message to internal images manually
+      UIImage *realSelf = self;
+      UIImage *realOther = other;
+      if (object_getClass(self) == DMDynamicImageProxy.class) {
+        realSelf = ((DMDynamicImageProxy *)self).resolvedImage;
+      }
+      if (object_getClass(other) == DMDynamicImageProxy.class) {
+        realOther = ((DMDynamicImageProxy *)other).resolvedImage;
+      }
+      return ((BOOL(*)(UIImage *, SEL, UIImage *))imp)(realSelf, selector, realOther);
+    }), method_getTypeEncoding(method));
+  });
 }
 
 + (UIImage *)dm_imageWithLightImage:(UIImage *)lightImage darkImage:(UIImage *)darkImage {
@@ -25,18 +45,4 @@
   return [UIImage dm_imageWithLightImage:lightImage darkImage:darkImage];
 }
 
-- (BOOL)dm_isEqual:(UIImage *)other {
-  /// On iOS 13, UIImage `isEqual:` somehow changes internally and doesn't work for `NSProxy`,
-  /// here we forward the message to internal images manually
-  UIImage *realSelf = self;
-  UIImage *realOther = other;
-  if (object_getClass(self) == DMDynamicImageProxy.class) {
-    realSelf = ((DMDynamicImageProxy *)self).resolvedImage;
-  }
-  if (object_getClass(other) == DMDynamicImageProxy.class) {
-    realOther = ((DMDynamicImageProxy *)other).resolvedImage;
-  }
-  return [realSelf dm_isEqual:realOther];
-}
-
 @end

Sources/DarkModeCore/UIView+DarkModeKit.m

@@ -10,24 +10,24 @@
 
 @implementation UIView (DarkModeKit)
 
-static void (*dm_original_setBackgroundColor)(UIView *, SEL, UIColor *);
-
-static void dm_setBackgroundColor(UIView *self, SEL _cmd, UIColor *color) {
-  if ([color isKindOfClass:[DMDynamicColor class]]) {
-    self.dm_dynamicBackgroundColor = (DMDynamicColor *)color;
-  } else {
-    self.dm_dynamicBackgroundColor = nil;
-  }
-  dm_original_setBackgroundColor(self, _cmd, color);
-}
-
-// https://stackoverflow.com/questions/42677534/swizzling-on-properties-that-conform-to-ui-appearance-selector
 + (void)dm_swizzleSetBackgroundColor {
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{
-    Method method = class_getInstanceMethod(self, @selector(setBackgroundColor:));
+    SEL selector = @selector(setBackgroundColor:);
-    dm_original_setBackgroundColor = (void *)method_getImplementation(method);
+    Method method = class_getInstanceMethod(self, selector);
-    method_setImplementation(method, (IMP)dm_setBackgroundColor);
+    if (!method)
+      NSAssert(NO, @"Method not found for [UIView setBackgroundColor:]");
+
+    IMP imp = method_getImplementation(method);
+    class_replaceMethod(self, selector, imp_implementationWithBlock(^(UIView *self, UIColor *backgroundColor) {
+      if ([backgroundColor isKindOfClass:[DMDynamicColor class]]) {
+        self.dm_dynamicBackgroundColor = (DMDynamicColor *)backgroundColor;
+      }
+      else {
+        self.dm_dynamicBackgroundColor = nil;
+      }
+      ((void (*)(UIView *, SEL, UIColor *))imp)(self, selector, backgroundColor);
+    }), method_getTypeEncoding(method));
   });
 }
 

Sources/DarkModeCore/include/DarkModeCore.h

@@ -6,7 +6,6 @@
 #import "../DMDynamicImage.h"
 #import "../DMNamespace.h"
 #import "../DMTraitCollection.h"
-#import "../NSObject+DarkModeKit.h"
 #import "../UIColor+DarkModeKit.h"
 #import "../UIImage+DarkModeKit.h"
 #import "../UIView+DarkModeKit.h"

Sources/FluentDarkModeKit/DarkModeManager.swift

@@ -18,6 +18,7 @@ public final class DarkModeManager: NSObject {
     UILabel.swizzleDidMoveToWindowOnce
 
     // Images
+    UIImage.dm_swizzleIsEqual()
     UIImageView.swizzleSetImageOnce
     UIImageView.swizzleInitImageOnce
     UITabBarItem.swizzleSetImageOnce

Sources/FluentDarkModeKit/Extensions/UIImageView+DarkModeKit.swift

@@ -15,23 +15,41 @@ extension UIImageView {
   }
 
   static let swizzleSetImageOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(setter: image), to: #selector(dm_setImage(_:))) {
+    let selector = #selector(setter: image)
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIImageView.self, selector: #selector(setter: image)))
+    guard let method = class_getInstanceMethod(UIImageView.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIImageView.self, selector: selector))
+      return
     }
+
+    let imp = method_getImplementation(method)
+    class_replaceMethod(UIImageView.self, selector, imp_implementationWithBlock({ (self: UIImageView, image: UIImage?) -> Void in
+      if object_getClass(image) == DMDynamicImageProxy.self {
+        self.dm_dynamicImage = image
+      }
+      else {
+        self.dm_dynamicImage = nil
+      }
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UIImageView, Selector, UIImage?) -> Void).self)
+      oldIMP(self, selector, image)
+    } as @convention(block) (UIImageView, UIImage?) -> Void), method_getTypeEncoding(method))
   }()
 
   static let swizzleInitImageOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(UIImageView.init(image:)), to: #selector(UIImageView.dm_init(image:))) {
+    let selector = #selector(UIImageView.init(image:))
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIImageView.self, selector: #selector(setter: image)))
+    guard let method = class_getInstanceMethod(UIImageView.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIImageView.self, selector: selector))
+      return
     }
-  }()
 
-  @objc dynamic func dm_init(image: UIImage?) -> UIImageView {
+    let imp = method_getImplementation(method)
-    if object_getClass(image) == DMDynamicImageProxy.self {
+    class_replaceMethod(UIImageView.self, selector, imp_implementationWithBlock({ (self: UIImageView, image: UIImage?) -> UIImageView in
-      dm_dynamicImage = image
+      if object_getClass(image) == DMDynamicImageProxy.self {
-    }
+        self.dm_dynamicImage = image
-    return dm_init(image: image)
+      }
-  }
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UIImageView, Selector, UIImage?) -> UIImageView).self)
+      return oldIMP(self, selector, image)
+    } as @convention(block) (UIImageView, UIImage?) -> UIImageView), method_getTypeEncoding(method))
+  }()
 
   override func dm_updateDynamicImages() {
     super.dm_updateDynamicImages()
@@ -40,14 +58,4 @@ extension UIImageView {
       image = dynamicImage
     }
   }
-
-  @objc dynamic func dm_setImage(_ image: UIImage?) {
-    if object_getClass(image) == DMDynamicImageProxy.self {
-      dm_dynamicImage = image
-    }
-    else {
-      dm_dynamicImage = nil
-    }
-    dm_setImage(image)
-  }
 }

Sources/FluentDarkModeKit/Extensions/UILabel+DarkModeKit.swift

@@ -9,9 +9,21 @@ extension UILabel {
   }
 
   static let swizzleDidMoveToWindowOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(didMoveToWindow), to: #selector(dm_didMoveToWindow)) {
+    let selector = #selector(didMoveToWindow)
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UILabel.self, selector: #selector(didMoveToWindow)))
+    guard let method = class_getInstanceMethod(UILabel.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UILabel.self, selector: selector))
+      return
     }
+
+    let imp = method_getImplementation(method)
+    class_replaceMethod(UILabel.self, selector, imp_implementationWithBlock({ (self: UILabel) -> Void in
+        let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UILabel, Selector) -> Void).self)
+        oldIMP(self, selector)
+        if self.currentUserInterfaceStyle != DMTraitCollection.current.userInterfaceStyle {
+          self.currentUserInterfaceStyle = DMTraitCollection.current.userInterfaceStyle
+          self.dmTraitCollectionDidChange(nil)
+        }
+      } as @convention(block) (UILabel) -> Void), method_getTypeEncoding(method))
   }()
 
   private var currentUserInterfaceStyle: DMUserInterfaceStyle? {
@@ -19,16 +31,14 @@ extension UILabel {
     set { objc_setAssociatedObject(self, &Constants.currentThemeKey, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC) }
   }
 
-  @objc private dynamic func dm_didMoveToWindow() {
-    dm_didMoveToWindow()
-    if currentUserInterfaceStyle != DMTraitCollection.current.userInterfaceStyle {
-      currentUserInterfaceStyle = DMTraitCollection.current.userInterfaceStyle
-      dmTraitCollectionDidChange(nil)
-    }
-  }
-
   override open func dmTraitCollectionDidChange(_ previousTraitCollection: DMTraitCollection?) {
     super.dmTraitCollectionDidChange(previousTraitCollection)
+
+    guard #available(iOS 12.0, *) else {
+      // Fix for iOS 11.x
+      updateDynamicColorInAttributedText()
+      return
+    }
   }
 
   private func updateDynamicColorInAttributedText() {

Sources/FluentDarkModeKit/Extensions/UITabBar+DarkModeKit.swift

@@ -33,15 +33,43 @@ extension UITabBarItem: DMTraitEnvironment {
   }
 
   static let swizzleSetImageOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(setter: image), to: #selector(dm_setImage(_:))) {
+    let selector = #selector(setter: image)
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITabBarItem.self, selector: #selector(setter: image)))
+    guard let method = class_getInstanceMethod(UITabBarItem.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITabBarItem.self, selector: selector))
+      return
     }
+
+    let imp = method_getImplementation(method)
+    class_replaceMethod(UITabBarItem.self, selector, imp_implementationWithBlock({ (self: UITabBarItem, image: UIImage?) -> Void in
+      if object_getClass(image) == DMDynamicImageProxy.self {
+        self.dm_dynamicImage = image
+      }
+      else {
+        self.dm_dynamicImage = nil
+      }
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UITabBarItem, Selector, UIImage?) -> Void).self)
+      oldIMP(self, selector, image)
+    } as @convention(block) (UITabBarItem, UIImage?) -> Void), method_getTypeEncoding(method))
   }()
 
   static let swizzleSetSelectedImageOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(setter: selectedImage), to: #selector(dm_setSelectedImage(_:))) {
+    let selector = #selector(setter: selectedImage)
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITabBarItem.self, selector: #selector(setter: selectedImage)))
+    guard let method = class_getInstanceMethod(UITabBarItem.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITabBarItem.self, selector: selector))
+      return
     }
+
+    let imp = method_getImplementation(method)
+    class_replaceMethod(UITabBarItem.self, selector, imp_implementationWithBlock({ (self: UITabBarItem, image: UIImage?) -> Void in
+      if object_getClass(image) == DMDynamicImageProxy.self {
+        self.dm_dynamicSelectedImage = image
+      }
+      else {
+        self.dm_dynamicSelectedImage = nil
+      }
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UITabBarItem, Selector, UIImage?) -> Void).self)
+      oldIMP(self, selector, image)
+    } as @convention(block) (UITabBarItem, UIImage?) -> Void), method_getTypeEncoding(method))
   }()
 
   open func dmTraitCollectionDidChange(_ previousTraitCollection: DMTraitCollection?) {
@@ -58,24 +86,4 @@ extension UITabBarItem: DMTraitEnvironment {
     }
   }
 
-  @objc dynamic func dm_setImage(_ image: UIImage?) {
-    if object_getClass(image) == DMDynamicImageProxy.self {
-      dm_dynamicImage = image
-    }
-    else {
-      dm_dynamicImage = nil
-    }
-    dm_setImage(image)
-  }
-
-  @objc dynamic func dm_setSelectedImage(_ image: UIImage?) {
-    if object_getClass(image) == DMDynamicImageProxy.self {
-      dm_dynamicSelectedImage = image
-    }
-    else {
-      dm_dynamicSelectedImage = nil
-    }
-    dm_setSelectedImage(image)
-  }
-
 }

Sources/FluentDarkModeKit/Extensions/UITextField+DarkModeKit.swift

@@ -26,16 +26,20 @@ extension UITextField {
 
   /// `UITextField` will not call `super.willMove(toWindow:)` in its implementation, so we need to swizzle it separately.
   static let swizzleTextFieldWillMoveToWindowOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(willMove(toWindow:)), to: #selector(dm_textFieldWillMove(toWindow:))) {
+    let selector = #selector(willMove(toWindow:))
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITextField.self, selector: #selector(willMove(toWindow:))))
+    guard let method = class_getInstanceMethod(UITextField.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UITextField.self, selector: selector))
+      return
     }
-  }()
 
-  @objc private dynamic func dm_textFieldWillMove(toWindow window: UIWindow?) {
+    let imp = method_getImplementation(method)
-    dm_textFieldWillMove(toWindow: window)
+    class_replaceMethod(UITextField.self, selector, imp_implementationWithBlock({ (self: UITextField, window: UIWindow?) -> Void in
-    if window != nil {
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UITextField, Selector, UIWindow?) -> Void).self)
-      dm_updateDynamicColors()
+      oldIMP(self, selector, window)
-      dm_updateDynamicImages()
+      if window != nil {
-    }
+        self.dm_updateDynamicColors()
-  }
+        self.dm_updateDynamicImages()
+      }
+    } as @convention(block) (UITextField, UIWindow?) -> Void), method_getTypeEncoding(method))
+  }()
 }

Sources/FluentDarkModeKit/Extensions/UIView+DarkModeKit.swift

@@ -28,18 +28,22 @@ extension UIView: DMTraitEnvironment {
 
 extension UIView {
   static let swizzleWillMoveToWindowOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(willMove(toWindow:)), to: #selector(dm_willMove(toWindow:))) {
+    let selector = #selector(willMove(toWindow:))
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIView.self, selector: #selector(willMove(toWindow:))))
+    guard let method = class_getInstanceMethod(UIView.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIView.self, selector: selector))
+      return
     }
-  }()
 
-  @objc private dynamic func dm_willMove(toWindow window: UIWindow?) {
+    let imp = method_getImplementation(method)
-    dm_willMove(toWindow: window)
+    class_replaceMethod(UIView.self, selector, imp_implementationWithBlock({ (self: UIView, window: UIWindow?) -> Void in
-    if window != nil {
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UIView, Selector, UIWindow?) -> Void).self)
-      dm_updateDynamicColors()
+      oldIMP(self, selector, window)
-      dm_updateDynamicImages()
+      if window != nil {
-    }
+        self.dm_updateDynamicColors()
-  }
+        self.dm_updateDynamicImages()
+      }
+    } as @convention(block) (UIView, UIWindow?) -> Void), method_getTypeEncoding(method))
+  }()
 }
 
 extension UIView {
@@ -48,18 +52,22 @@ extension UIView {
   }
 
   static let swizzleSetTintColorOnce: Void = {
-    if !dm_swizzleInstanceMethod(#selector(setter: tintColor), to: #selector(dm_setTintColor)) {
+    let selector = #selector(setter: tintColor)
-      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIView.self, selector: #selector(setter: tintColor)))
+    guard let method = class_getInstanceMethod(UIView.self, selector) else {
+      assertionFailure(DarkModeManager.messageForSwizzlingFailed(class: UIView.self, selector: selector))
+      return
     }
+
+    let imp = method_getImplementation(method)
+    class_replaceMethod(UIView.self, selector, imp_implementationWithBlock({ (self: UIView, tintColor: UIColor) -> Void in
+      self.dm_dynamicTintColor = tintColor as? DynamicColor
+      let oldIMP = unsafeBitCast(imp, to: (@convention(c) (UIView, Selector, UIColor) -> Void).self)
+      oldIMP(self, selector, tintColor)
+    } as @convention(block) (UIView, UIColor) -> Void), method_getTypeEncoding(method))
   }()
 
   private var dm_dynamicTintColor: DynamicColor? {
     get { return objc_getAssociatedObject(self, &Constants.dynamicTintColorKey) as? DynamicColor }
     set { objc_setAssociatedObject(self, &Constants.dynamicTintColorKey, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC) }
   }
-
-  @objc private dynamic func dm_setTintColor(_ color: UIColor) {
-    dm_dynamicTintColor = color as? DynamicColor
-    dm_setTintColor(color)
-  }
 }

Sources/FluentDarkModeKitExample/MainViewController.swift

@@ -15,6 +15,7 @@ final class MainViewController: ViewController {
     Row(name: "UIView", vcType: UIViewVC.self),
     Row(name: "UIActivityIndicatorView", vcType: UIActivityIndicatorViewVC.self),
     Row(name: "UIButton", vcType: UIButtonVC.self),
+    Row(name: "UILabel", vcType: UILabelVC.self),
     Row(name: "UIPageControl", vcType: UIPageControlVC.self)
   ]
 

Sources/FluentDarkModeKitExample/UILabelVC.swift

@@ -0,0 +1,30 @@
+//
+//  Copyright (c) Microsoft Corporation. All rights reserved.
+//  Licensed under the MIT License.
+//
+
+import FluentDarkModeKit
+
+final class UILabelVC: ViewController {
+  let label: UILabel = {
+    let label = UILabel()
+    label.text = "Test"
+    label.textColor = UIColor(.dm, light: .red, dark: .green)
+    return label
+  }()
+
+  override func viewDidLoad() {
+    super.viewDidLoad()
+
+    view.backgroundColor = UIColor(.dm, light: .white, dark: .black)
+
+    view.addSubview(label)
+  }
+
+  override func viewDidLayoutSubviews() {
+    super.viewDidLayoutSubviews()
+
+    label.sizeToFit()
+    label.center = view.center
+  }
+}