refactor: move RCTUIKit into a separate module (#2847)

## Summary:

RCTUIKit has long been one monolithic file inside `React-Core` where I'd
rather it's closer to other frameworks and follows the umbrella header +
separate file pattern. And ideally also it's own pod and clang module.
Let's do that ahead of the 0.83 merge, since that one introduces some
use of RCTUIKit into SwiftUI code.

- Move `RCTUIKit` into `packeges/react-native/React/RCTUIKit`
- Break up the file into multiple headers and implementations
- Uses `@compatibility_alias` instead of `#define` or `typedef` for
Swift compatibility
- Move around some code so that the ios and macos blocks are more
inlined rather than one giant block after another
- Fixes some definitions that were RCTUI* (RCTUIColor, RCTUIApplication,
..) but should have been RCTPlatform*.
- This changed RCTUIColor to RCTPlatformColor which is 90% of the
changes here. Since downstream code might use the old define, I also
kept a `#define RCTUIColor RCTPlatformColor` for backwards
compatibility).

## Test Plan:

CI should pass

Author: Saadnajmi

packages/react-native-test-library/ios/RCTSampleNativeComponentComponentView.mm

@@ -18,14 +18,14 @@
 
 using namespace facebook::react;
 
-static RCTUIColor *RCTUIColorFromHexString(const std::string hexString) // [macOS]
+static RCTPlatformColor *RCTUIColorFromHexString(const std::string hexString) // [macOS]
 {
   unsigned rgbValue = 0;
   NSString *colorString = [NSString stringWithCString:hexString.c_str() encoding:[NSString defaultCStringEncoding]];
   NSScanner *scanner = [NSScanner scannerWithString:colorString];
   [scanner setScanLocation:1]; // bypass '#' character
   [scanner scanHexInt:&rgbValue];
-  return [RCTUIColor colorWithRed:((rgbValue & 0xFF0000) >> 16) / 255.0 // [macOS]
+  return [RCTPlatformColor colorWithRed:((rgbValue & 0xFF0000) >> 16) / 255.0 // [macOS]
                             green:((rgbValue & 0xFF00) >> 8) / 255.0
                              blue:(rgbValue & 0xFF) / 255.0
                             alpha:1.0];

packages/react-native-test-library/ios/RCTSampleNativeComponentViewManager.mm

@@ -11,14 +11,14 @@
 
 #import <string>
 
-static RCTUIColor *UIColorFromHexString(const std::string hexString) // [macOS]
+static RCTPlatformColor *UIColorFromHexString(const std::string hexString) // [macOS]
 {
   unsigned rgbValue = 0;
   NSString *colorString = [NSString stringWithCString:hexString.c_str() encoding:[NSString defaultCStringEncoding]];
   NSScanner *scanner = [NSScanner scannerWithString:colorString];
   [scanner setScanLocation:1]; // bypass '#' character
   [scanner scanHexInt:&rgbValue];
-  return [RCTUIColor colorWithRed:((rgbValue & 0xFF0000) >> 16) / 255.0 // [macOS]
+  return [RCTPlatformColor colorWithRed:((rgbValue & 0xFF0000) >> 16) / 255.0 // [macOS]
                             green:((rgbValue & 0xFF00) >> 8) / 255.0
                              blue:(rgbValue & 0xFF) / 255.0
                             alpha:1.0];

packages/react-native/Libraries/NativeAnimation/Nodes/RCTInterpolationAnimatedNode.mm

@@ -103,8 +103,8 @@ - (instancetype)initWithTag:(NSNumber *)tag config:(NSDictionary<NSString *, id>
     for (id value in outputRangeConfig) {
       switch (_outputType) {
         case RCTInterpolationOutputColor: {
-          RCTUIColor *color = [RCTConvert UIColor:value]; // [macOS]
-          [outputRange addObject:color ? color : [RCTUIColor whiteColor]]; // [macOS]
+          RCTPlatformColor *color = [RCTConvert UIColor:value]; // [macOS]
+          [outputRange addObject:color ? color : [RCTPlatformColor whiteColor]]; // [macOS]
           break;
         }
         case RCTInterpolationOutputString:

packages/react-native/Libraries/NativeAnimation/RCTAnimationUtils.h

@@ -34,7 +34,7 @@ RCT_EXTERN CGFloat RCTInterpolateValueInRange(
     NSString *extrapolateRight);
 
 RCT_EXTERN uint32_t
-RCTInterpolateColorInRange(CGFloat value, NSArray<NSNumber *> *inputRange, NSArray<RCTUIColor *> *outputRange); // [macOS]
+RCTInterpolateColorInRange(CGFloat value, NSArray<NSNumber *> *inputRange, NSArray<RCTPlatformColor *> *outputRange); // [macOS]
 
 // Represents a color as a int32_t. RGB components are assumed to be in [0-255] range and alpha in [0-1] range
 RCT_EXTERN uint32_t RCTColorFromComponents(CGFloat red, CGFloat green, CGFloat blue, CGFloat alpha);

packages/react-native/Libraries/NativeAnimation/RCTAnimationUtils.mm

@@ -84,7 +84,7 @@ CGFloat RCTInterpolateValueInRange(
   return RCTInterpolateValue(value, inputMin, inputMax, outputMin, outputMax, extrapolateLeft, extrapolateRight);
 }
 
-uint32_t RCTInterpolateColorInRange(CGFloat value, NSArray<NSNumber *> *inputRange, NSArray<RCTUIColor *> *outputRange) // [macOS]
+uint32_t RCTInterpolateColorInRange(CGFloat value, NSArray<NSNumber *> *inputRange, NSArray<RCTPlatformColor *> *outputRange) // [macOS]
 {
   NSUInteger rangeIndex = RCTFindIndexOfNearestValue(value, inputRange);
   CGFloat inputMin = inputRange[rangeIndex].doubleValue;

packages/react-native/Libraries/Text/RCTTextAttributes.h

@@ -25,8 +25,8 @@ extern NSString *const RCTTextAttributesTagAttributeName;
 @interface RCTTextAttributes : NSObject <NSCopying>
 
 // Color
-@property (nonatomic, strong, nullable) RCTUIColor *foregroundColor; // [macOS]
-@property (nonatomic, strong, nullable) RCTUIColor *backgroundColor; // [macOS]
+@property (nonatomic, strong, nullable) RCTPlatformColor *foregroundColor; // [macOS]
+@property (nonatomic, strong, nullable) RCTPlatformColor *backgroundColor; // [macOS]
 @property (nonatomic, assign) CGFloat opacity;
 // Font
 @property (nonatomic, copy, nullable) NSString *fontFamily;
@@ -46,13 +46,13 @@ extern NSString *const RCTTextAttributesTagAttributeName;
 @property (nonatomic, assign) NSLineBreakStrategy lineBreakStrategy;
 @property (nonatomic, assign) NSLineBreakMode lineBreakMode;
 // Decoration
-@property (nonatomic, strong, nullable) RCTUIColor *textDecorationColor; // [macOS]
+@property (nonatomic, strong, nullable) RCTPlatformColor *textDecorationColor; // [macOS]
 @property (nonatomic, assign) NSUnderlineStyle textDecorationStyle;
 @property (nonatomic, assign) RCTTextDecorationLineType textDecorationLine;
 // Shadow
 @property (nonatomic, assign) CGSize textShadowOffset;
 @property (nonatomic, assign) CGFloat textShadowRadius;
-@property (nonatomic, strong, nullable) RCTUIColor *textShadowColor; // [macOS]
+@property (nonatomic, strong, nullable) RCTPlatformColor *textShadowColor; // [macOS]
 // Special
 @property (nonatomic, assign) BOOL isHighlighted;
 @property (nonatomic, strong, nullable) NSNumber *tag;
@@ -92,8 +92,8 @@ extern NSString *const RCTTextAttributesTagAttributeName;
 /**
  * Foreground and background colors with opacity and right defaults.
  */
-- (RCTUIColor *)effectiveForegroundColor; // [macOS]
-- (RCTUIColor *)effectiveBackgroundColor; // [macOS]
+- (RCTPlatformColor *)effectiveForegroundColor; // [macOS]
+- (RCTPlatformColor *)effectiveBackgroundColor; // [macOS]
 
 /**
  * Text transformed per 'none', 'uppercase', 'lowercase', 'capitalize'

packages/react-native/Libraries/Text/RCTTextAttributes.mm

@@ -18,9 +18,9 @@
 @implementation RCTTextAttributes
 
 // [macOS
-+ (RCTUIColor *)defaultForegroundColor
++ (RCTPlatformColor *)defaultForegroundColor
 {
-  return [RCTUIColor labelColor];
+  return [RCTPlatformColor labelColor];
 }
 // macOS]
 
@@ -175,7 +175,7 @@ - (NSParagraphStyle *)effectiveParagraphStyle
   }
 
   // Colors
-  RCTUIColor *effectiveForegroundColor = self.effectiveForegroundColor; // [macOS]
+  RCTPlatformColor *effectiveForegroundColor = self.effectiveForegroundColor; // [macOS]
 
   if (_foregroundColor || !isnan(_opacity)) {
     attributes[NSForegroundColorAttributeName] = effectiveForegroundColor;
@@ -275,9 +275,9 @@ - (CGFloat)effectiveFontSizeMultiplier
   }
 }
 
-- (RCTUIColor *)effectiveForegroundColor // [macOS]
+- (RCTPlatformColor *)effectiveForegroundColor // [macOS]
 {
-  RCTUIColor *effectiveForegroundColor = _foregroundColor ?: [RCTUIColor blackColor]; // [macOS]
+  RCTPlatformColor *effectiveForegroundColor = _foregroundColor ?: [RCTPlatformColor blackColor]; // [macOS]
 
   if (!isnan(_opacity)) {
     effectiveForegroundColor =
@@ -287,16 +287,16 @@ - (RCTUIColor *)effectiveForegroundColor // [macOS]
   return effectiveForegroundColor;
 }
 
-- (RCTUIColor *)effectiveBackgroundColor // [macOS]
+- (RCTPlatformColor *)effectiveBackgroundColor // [macOS]
 {
-  RCTUIColor *effectiveBackgroundColor = _backgroundColor; // ?: [[UIColor whiteColor] colorWithAlphaComponent:0]; // [macOS]
+  RCTPlatformColor *effectiveBackgroundColor = _backgroundColor; // ?: [[UIColor whiteColor] colorWithAlphaComponent:0]; // [macOS]
 
   if (effectiveBackgroundColor && !isnan(_opacity)) {
     effectiveBackgroundColor =
         [effectiveBackgroundColor colorWithAlphaComponent:CGColorGetAlpha(effectiveBackgroundColor.CGColor) * _opacity];
   }
 
-  return effectiveBackgroundColor ?: [RCTUIColor clearColor]; // [macOS]
+  return effectiveBackgroundColor ?: [RCTPlatformColor clearColor]; // [macOS]
 }
 
 static NSString *capitalizeText(NSString *text)

packages/react-native/Libraries/Text/Text/RCTTextView.mm

@@ -271,7 +271,7 @@ - (void)drawRect:(CGRect)rect
   if (highlightPath) {
     if (!_highlightLayer) {
       _highlightLayer = [CAShapeLayer layer];
-      _highlightLayer.fillColor = [RCTUIColor colorWithWhite:0 alpha:0.25].CGColor; // [macOS]
+      _highlightLayer.fillColor = [RCTPlatformColor colorWithWhite:0 alpha:0.25].CGColor; // [macOS]
       [self.layer addSublayer:_highlightLayer];
     }
     _highlightLayer.position = _contentFrame.origin;

packages/react-native/Libraries/Text/TextInput/Multiline/RCTMultilineTextInputView.mm

@@ -27,7 +27,7 @@ - (instancetype)initWithBridge:(RCTBridge *)bridge
 #if TARGET_OS_OSX // [macOS
     self.hideVerticalScrollIndicator = NO;
     _scrollView = [[RCTUIScrollView alloc] initWithFrame:self.bounds];
-    _scrollView.backgroundColor = [RCTUIColor clearColor];
+    _scrollView.backgroundColor = [RCTPlatformColor clearColor];
     _scrollView.drawsBackground = NO;
     _scrollView.borderType = NSNoBorder;
     _scrollView.hasHorizontalRuler = NO;

packages/react-native/Libraries/Text/TextInput/Multiline/RCTUITextView.h

@@ -32,7 +32,7 @@
  #endif // macOS]
  @property (nonatomic, assign, readonly) BOOL dictationRecognizing;
  @property (nonatomic, copy, nullable) NSString *placeholder;
- @property (nonatomic, strong, nullable) RCTUIColor *placeholderColor; // [macOS]
+ @property (nonatomic, strong, nullable) RCTPlatformColor *placeholderColor; // [macOS]
 
  @property (nonatomic, assign) CGFloat preferredMaxLayoutWidth;
 
@@ -51,8 +51,8 @@
 
  #if TARGET_OS_OSX // [macOS
  @property (nonatomic, getter=isScrollEnabled) BOOL scrollEnabled;
- @property (nonatomic, strong, nullable) RCTUIColor *selectionColor;
- @property (nonatomic, strong, nullable) RCTUIColor *cursorColor;
+ @property (nonatomic, strong, nullable) RCTPlatformColor *selectionColor;
+ @property (nonatomic, strong, nullable) RCTPlatformColor *cursorColor;
  @property (nonatomic, assign) UIEdgeInsets textContainerInsets;
  @property (nonatomic, copy) NSString *text;
  @property (nonatomic, assign) NSTextAlignment textAlignment;