[Fabric] Shim RCTUILabel (microsoft#1576)

* Shim RCTUILabel

* Conditionally ignore UIKit apis for UILabel

* Shim the RCTLabel to render correctly

* Re-add removed code

Co-authored-by: Shawn Dempsey <shawndempsey@fb.com>
# Conflicts:
#	React/Base/macOS/RCTUIKit.m

# Conflicts:
#	React/Base/macOS/RCTUIKit.m

Author: shwanton

React/Base/RCTUIKit.h

@@ -486,18 +486,20 @@ NS_INLINE CGRect CGRectValue(NSValue *value)
 // fabric component types
 //
 
+// RCTUISlider
+
 #if !TARGET_OS_OSX // [TODO(macOS GH#774)
 #define RCTUISlider UISlider
 #else
 @interface RCTUISlider : NSSlider
 @end
 #endif // ]TODO(macOS GH#774)
 
-// RCTUISwitch
+// RCTUILabel
 
 #if !TARGET_OS_OSX // [TODO(macOS GH#774)
-#define RCTUISwitch UISwitch
+#define RCTUILabel UILabel
 #else
-@interface RCTUISwitch : NSSwitch
+@interface RCTUILabel : NSTextField
 @end
 #endif // ]TODO(macOS GH#774)

React/Base/macOS/RCTUIKit.m

@@ -589,3 +589,23 @@ - (NSRect)constrainBoundsRect:(NSRect)proposedBounds
 }
 
 @end
+
+// RCTUILabel
+
+@implementation RCTUILabel {} // [TODO(macOS GH#774)
+
+- (instancetype)initWithFrame:(NSRect)frameRect
+{
+  if (self = [super initWithFrame:frameRect]) {
+    [self setBezeled:NO];
+    [self setDrawsBackground:NO];
+    [self setEditable:NO];
+    [self setSelectable:NO];
+    [self setWantsLayer:YES];
+  }
+  
+  return self;
+}
+
+@end  // ]TODO(macOS GH#774)
+

React/Fabric/Mounting/ComponentViews/UnimplementedComponent/RCTUnimplementedNativeComponentView.mm

@@ -14,7 +14,7 @@
 using namespace facebook::react;
 
 @implementation RCTUnimplementedNativeComponentView {
-  UILabel *_label;
+  RCTUILabel *_label; // TODO(macOS GH#774)
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -24,9 +24,11 @@ - (instancetype)initWithFrame:(CGRect)frame
     _props = defaultProps;
 
     CGRect bounds = self.bounds;
-    _label = [[UILabel alloc] initWithFrame:bounds];
-    _label.backgroundColor = [RCTUIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.3]; // TODO(macOS GH#774)
+    _label = [[RCTUILabel alloc] initWithFrame:bounds];  // TODO(macOS GH#774)
+    _label.backgroundColor = [RCTUIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.3];
+#if !TARGET_OS_OSX // [TODO(macOS GH#774)
     _label.layoutMargins = UIEdgeInsetsMake(12, 12, 12, 12);
+#endif // ]TODO(macOS GH#774)
     _label.lineBreakMode = NSLineBreakByWordWrapping;
     _label.numberOfLines = 0;
     _label.textAlignment = NSTextAlignmentCenter;

React/Fabric/Mounting/ComponentViews/UnimplementedView/RCTUnimplementedViewComponentView.mm

@@ -21,7 +21,7 @@
 using namespace facebook::react;
 
 @implementation RCTUnimplementedViewComponentView {
-  UILabel *_label;
+  RCTUILabel *_label; // TODO(macOS GH#774)
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -30,16 +30,26 @@ - (instancetype)initWithFrame:(CGRect)frame
     static auto const defaultProps = std::make_shared<UnimplementedViewProps const>();
     _props = defaultProps;
 
-    _label = [[UILabel alloc] initWithFrame:self.bounds];
+    _label = [[RCTUILabel alloc] initWithFrame:self.bounds]; // TODO(macOS GH#774)
     _label.backgroundColor = [RCTUIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.3]; // TODO(macOS GH#774)
     _label.lineBreakMode = NSLineBreakByCharWrapping;
+#if !TARGET_OS_OSX // [TODO(macOS GH#774)
     _label.numberOfLines = 0;
     _label.textAlignment = NSTextAlignmentCenter;
+#else
+    _label.alignment = NSTextAlignmentCenter;
+#endif // ]TODO(macOS GH#774)
     _label.textColor = [RCTUIColor whiteColor]; // TODO(macOS GH#774)
     _label.allowsDefaultTighteningForTruncation = YES;
+#if !TARGET_OS_OSX // [TODO(macOS GH#774)
     _label.adjustsFontSizeToFitWidth = YES;
+#endif // ]TODO(macOS GH#774)
 
+#if !TARGET_OS_OSX // [TODO(macOS GH#774)
     self.contentView = _label;
+#else
+    [self.contentView addSubview:_label];
+#endif // ]TODO(macOS GH#774)
   }
 
   return self;