introduce RCTPlatformColorUtils

Summary:
Changelog: [Internal]

in this diff, we add the logic to handle converting PlatformColor strings to their corresponding RGBA values, using `UIColor`'s API as the source of truth of these colors.

functionality not covered yet:
- customColor
- iOS Dynamic Colors
- Variant Colors

Reviewed By: sammy-SC

Differential Revision: D30103451

fbshipit-source-id: 7d7be0f08dc2fb95b606b8f5d73784766787a574

ReactCommon/react/renderer/graphics/React-graphics.podspec

@@ -39,4 +39,5 @@ Pod::Spec.new do |s|
   s.pod_target_xcconfig  = { "USE_HEADERMAP" => "NO", "HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/boost\" \"$(PODS_TARGET_SRCROOT)/../../../\" \"$(PODS_ROOT)/RCT-Folly\"" }
 
   s.dependency "RCT-Folly/Fabric", folly_version
+  s.dependency "React-Core/Default", version
 end

ReactCommon/react/renderer/graphics/platform/ios/RCTPlatformColorUtils.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <react/renderer/graphics/ColorComponents.h>
+#include <vector>
+
+facebook::react::ColorComponents RCTPlatformColorComponentsFromSemanticItems(
+    std::vector<std::string> &semanticItems);

ReactCommon/react/renderer/graphics/platform/ios/RCTPlatformColorUtils.mm

@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "RCTPlatformColorUtils.h"
+
+#import <Foundation/Foundation.h>
+#import <React/RCTUtils.h>
+#import <UIKit/UIKit.h>
+
+#include <string>
+
+NS_ASSUME_NONNULL_BEGIN
+
+static NSString *const kColorSuffix = @"Color";
+static NSString *const kFallbackARGBKey = @"fallback-argb";
+
+static NSDictionary<NSString *, NSDictionary *> *_PlatformColorSelectorsDict()
+{
+  static NSDictionary<NSString *, NSDictionary *> *dict;
+  static dispatch_once_t once_token;
+  dispatch_once(&once_token, ^(void) {
+    dict = @{
+      // https://developer.apple.com/documentation/uikit/uicolor/ui_element_colors
+      // Label Colors
+      @"label" : @{
+        kFallbackARGBKey : @(0xFF000000) // iOS 13.0
+      },
+      @"secondaryLabel" : @{
+        kFallbackARGBKey : @(0x993c3c43) // iOS 13.0
+      },
+      @"tertiaryLabel" : @{
+        kFallbackARGBKey : @(0x4c3c3c43) // iOS 13.0
+      },
+      @"quaternaryLabel" : @{
+        kFallbackARGBKey : @(0x2d3c3c43) // iOS 13.0
+      },
+      // Fill Colors
+      @"systemFill" : @{
+        kFallbackARGBKey : @(0x33787880) // iOS 13.0
+      },
+      @"secondarySystemFill" : @{
+        kFallbackARGBKey : @(0x28787880) // iOS 13.0
+      },
+      @"tertiarySystemFill" : @{
+        kFallbackARGBKey : @(0x1e767680) // iOS 13.0
+      },
+      @"quaternarySystemFill" : @{
+        kFallbackARGBKey : @(0x14747480) // iOS 13.0
+      },
+      // Text Colors
+      @"placeholderText" : @{
+        kFallbackARGBKey : @(0x4c3c3c43) // iOS 13.0
+      },
+      // Standard Content Background Colors
+      @"systemBackground" : @{
+        kFallbackARGBKey : @(0xFFffffff) // iOS 13.0
+      },
+      @"secondarySystemBackground" : @{
+        kFallbackARGBKey : @(0xFFf2f2f7) // iOS 13.0
+      },
+      @"tertiarySystemBackground" : @{
+        kFallbackARGBKey : @(0xFFffffff) // iOS 13.0
+      },
+      // Grouped Content Background Colors
+      @"systemGroupedBackground" : @{
+        kFallbackARGBKey : @(0xFFf2f2f7) // iOS 13.0
+      },
+      @"secondarySystemGroupedBackground" : @{
+        kFallbackARGBKey : @(0xFFffffff) // iOS 13.0
+      },
+      @"tertiarySystemGroupedBackground" : @{
+        kFallbackARGBKey : @(0xFFf2f2f7) // iOS 13.0
+      },
+      // Separator Colors
+      @"separator" : @{
+        kFallbackARGBKey : @(0x493c3c43) // iOS 13.0
+      },
+      @"opaqueSeparator" : @{
+        kFallbackARGBKey : @(0xFFc6c6c8) // iOS 13.0
+      },
+      // Link Color
+      @"link" : @{
+        kFallbackARGBKey : @(0xFF007aff) // iOS 13.0
+      },
+      // Nonadaptable Colors
+      @"darkText" : @{},
+      @"lightText" : @{},
+      // https://developer.apple.com/documentation/uikit/uicolor/standard_colors
+      // Adaptable Colors
+      @"systemBlue" : @{},
+      @"systemBrown" : @{
+        kFallbackARGBKey : @(0xFFa2845e) // iOS 13.0
+      },
+      @"systemGreen" : @{},
+      @"systemIndigo" : @{
+        kFallbackARGBKey : @(0xFF5856d6) // iOS 13.0
+      },
+      @"systemOrange" : @{},
+      @"systemPink" : @{},
+      @"systemPurple" : @{},
+      @"systemRed" : @{},
+      @"systemTeal" : @{},
+      @"systemYellow" : @{},
+      // Adaptable Gray Colors
+      @"systemGray" : @{},
+      @"systemGray2" : @{
+        kFallbackARGBKey : @(0xFFaeaeb2) // iOS 13.0
+      },
+      @"systemGray3" : @{
+        kFallbackARGBKey : @(0xFFc7c7cc) // iOS 13.0
+      },
+      @"systemGray4" : @{
+        kFallbackARGBKey : @(0xFFd1d1d6) // iOS 13.0
+      },
+      @"systemGray5" : @{
+        kFallbackARGBKey : @(0xFFe5e5ea) // iOS 13.0
+      },
+      @"systemGray6" : @{
+        kFallbackARGBKey : @(0xFFf2f2f7) // iOS 13.0
+      },
+      // Transparent Color
+      @"clear" : @{
+        kFallbackARGBKey : @(0x00000000) // iOS 13.0
+      },
+    };
+  });
+  return dict;
+}
+
+static UIColor *_UIColorFromHexValue(NSNumber *hexValue)
+{
+  NSUInteger hexIntValue = [hexValue unsignedIntegerValue];
+
+  CGFloat red = ((CGFloat)((hexIntValue & 0xFF000000) >> 24)) / 255.0;
+  CGFloat green = ((CGFloat)((hexIntValue & 0xFF0000) >> 16)) / 255.0;
+  CGFloat blue = ((CGFloat)((hexIntValue & 0xFF00) >> 8)) / 255.0;
+  CGFloat alpha = ((CGFloat)(hexIntValue & 0xFF)) / 255.0;
+
+  return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
+}
+
+static UIColor *_Nullable _UIColorFromSemanticString(NSString *semanticString)
+{
+  NSString *platformColorString = [semanticString hasSuffix:kColorSuffix]
+      ? [semanticString substringToIndex:[semanticString length] - [kColorSuffix length]]
+      : semanticString;
+  NSDictionary<NSString *, NSDictionary *> *platformColorSelectorsDict = _PlatformColorSelectorsDict();
+  NSDictionary<NSString *, id> *colorInfo = platformColorSelectorsDict[platformColorString];
+  if (colorInfo) {
+    SEL objcColorSelector = NSSelectorFromString([platformColorString stringByAppendingString:kColorSuffix]);
+    if (![UIColor respondsToSelector:objcColorSelector]) {
+      NSNumber *fallbackRGB = colorInfo[kFallbackARGBKey];
+      if (fallbackRGB) {
+        return _UIColorFromHexValue(fallbackRGB);
+      }
+    } else {
+      Class uiColorClass = [UIColor class];
+      IMP imp = [uiColorClass methodForSelector:objcColorSelector];
+      id (*getUIColor)(id, SEL) = ((id(*)(id, SEL))imp);
+      id colorObject = getUIColor(uiColorClass, objcColorSelector);
+      if ([colorObject isKindOfClass:[UIColor class]]) {
+        return colorObject;
+      }
+    }
+  }
+  return nil;
+}
+
+static inline NSString *_NSStringFromCString(
+    const std::string &string,
+    const NSStringEncoding &encoding = NSUTF8StringEncoding)
+{
+  return [NSString stringWithCString:string.c_str() encoding:encoding];
+}
+
+static inline facebook::react::ColorComponents _ColorComponentsFromUIColor(UIColor *color)
+{
+  CGFloat rgba[4];
+  RCTGetRGBAColorComponents(color.CGColor, rgba);
+  return {(float)rgba[0], (float)rgba[1], (float)rgba[2], (float)rgba[3]};
+}
+
+facebook::react::ColorComponents RCTPlatformColorComponentsFromSemanticItems(std::vector<std::string> &semanticItems)
+{
+  for (const auto &semanticCString : semanticItems) {
+    if (@available(iOS 11.0, *)) {
+      NSString *semanticNSString = _NSStringFromCString(semanticCString);
+      UIColor *uiColor = [UIColor colorNamed:semanticNSString];
+      if (uiColor != nil) {
+        return _ColorComponentsFromUIColor(uiColor);
+      }
+      uiColor = _UIColorFromSemanticString(semanticNSString);
+      if (uiColor != nil) {
+        return _ColorComponentsFromUIColor(uiColor);
+      }
+    }
+  }
+
+  return {0, 0, 0, 0};
+}
+
+NS_ASSUME_NONNULL_END

packages/rn-tester/Podfile.lock

@@ -583,6 +583,7 @@ PODS:
     - ReactCommon/turbomodule/core (= 1000.0.0)
   - React-graphics (1000.0.0):
     - RCT-Folly/Fabric (= 2021.06.28.00)
+    - React-Core/Default (= 1000.0.0)
   - React-jsi (1000.0.0):
     - boost (= 1.76.0)
     - DoubleConversion
@@ -879,7 +880,7 @@ SPEC CHECKSUMS:
   React-CoreModules: 5ee1ed4f8b7f8bdbd45ed155a15c601dca9c73dd
   React-cxxreact: 20a63475c83c5450442c754305738c6db6070214
   React-Fabric: 7641eab239c5fc5669ef22ea08cf383f9066fdcb
-  React-graphics: 3ea907482e46997c9a14c60521918985f9425504
+  React-graphics: db797c4609216593a1a12d1661716898d303900f
   React-jsi: 7cc3d3691803478047e7d2c8eb5d4c2f9c6d2922
   React-jsiexecutor: 02ed9d4a28a8acf44788b4697e13c4aadc42cf72
   React-jsinspector: 7d223826b0e7a61b3540c21b9eca2603b1d4e823