Use NSForegroundColorAttributeName for links in ASTextNodes by subclassing NSLayoutManager

AsyncDisplayKit/TextKit/ASLayoutManager.m

@@ -0,0 +1,41 @@
+/* Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "ASLayoutManager.h"
+
+@implementation ASLayoutManager
+
+- (void)showCGGlyphs:(const CGGlyph *)glyphs
+           positions:(const CGPoint *)positions
+               count:(NSUInteger)glyphCount
+                font:(UIFont *)font
+              matrix:(CGAffineTransform)textMatrix
+          attributes:(NSDictionary *)attributes
+           inContext:(CGContextRef)graphicsContext
+{
+
+  // NSLayoutManager has a hard coded internal color for hyperlinks which ignores
+  // NSForegroundColorAttributeName. To get around this, we force the fill color
+  // in the current context to match NSForegroundColorAttributeName.
+  UIColor *foregroundColor = attributes[NSForegroundColorAttributeName];
+  
+  if (foregroundColor)
+  {
+    CGContextSetFillColorWithColor(graphicsContext, foregroundColor.CGColor);
+  }
+  
+  [super showCGGlyphs:glyphs
+            positions:positions
+                count:glyphCount
+                 font:font
+               matrix:textMatrix
+           attributes:attributes
+            inContext:graphicsContext];
+}
+
+@end