Convert ASTextKitComponents to an object.

ARC doesn't play nicely with structs that contain references to
Objective-C objects, which causes breakage when using AsyncDisplayKit as
a dynamic framework (e.g., with CocoaPods 0.36+).  Fixes #198.

AsyncDisplayKit/ASEditableTextNode.mm

@@ -49,8 +49,8 @@
 
   // TextKit.
   ASDN::RecursiveMutex _textKitLock;
-  ASTextKitComponents _textKitComponents;
+  ASTextKitComponents *_textKitComponents;
-  ASTextKitComponents _placeholderTextKitComponents;
+  ASTextKitComponents *_placeholderTextKitComponents;
   // Forwards NSLayoutManagerDelegate methods related to word kerning
   ASTextNodeWordKerner *_wordKerner;
 
@@ -133,7 +133,7 @@
 
 - (CGSize)calculateSizeThatFits:(CGSize)constrainedSize
 {
-  ASTextKitComponents displayedComponents = [self isDisplayingPlaceholder] ? _placeholderTextKitComponents : _textKitComponents;
+  ASTextKitComponents *displayedComponents = [self isDisplayingPlaceholder] ? _placeholderTextKitComponents : _textKitComponents;
   CGSize textSize = ASTextKitComponentsSizeForConstrainedWidth(displayedComponents, constrainedSize.width);
   return CGSizeMake(constrainedSize.width, fminf(textSize.height, constrainedSize.height));
 }

AsyncDisplayKit/Details/ASTextNodeRenderer.mm

@@ -505,7 +505,7 @@ static const CGFloat ASTextNodeRendererTextCapHeightPadding = 1.3;
   CGRect lastLineRect = [_layoutManager lineFragmentRectForGlyphAtIndex:lastVisibleGlyphIndex effectiveRange:NULL];
 
   // Calculate the bounding rectangle for the truncation message
-  ASTextKitComponents truncationComponents = ASTextKitComponentsCreate(_truncationString, constrainedRect.size);
+  ASTextKitComponents *truncationComponents = ASTextKitComponentsCreate(_truncationString, constrainedRect.size);
 
   // Size the truncation message
   [truncationComponents.layoutManager ensureLayoutForTextContainer:truncationComponents.textContainer];

AsyncDisplayKit/Details/ASTextNodeTextKitHelpers.h

@@ -11,12 +11,14 @@
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
 
-typedef struct {
+@interface ASTextKitComponents : NSObject
-  NSTextStorage *textStorage;
+
-  NSTextContainer *textContainer;
+@property (nonatomic, strong) NSTextStorage *textStorage;
-  NSLayoutManager *layoutManager;
+@property (nonatomic, strong) NSTextContainer *textContainer;
-  UITextView *textView;
+@property (nonatomic, strong) NSLayoutManager *layoutManager;
-} ASTextKitComponents;
+@property (nonatomic, strong) UITextView *textView;
+
+@end
 
 // Convenience.
 /**
@@ -26,11 +28,11 @@ typedef struct {
   @return A `ASTextKitComponents` containing the created components. The text view component will be nil.
   @discussion The returned components will be hooked up together, so they are ready for use as a system upon return.
  */
-extern ASTextKitComponents ASTextKitComponentsCreate(NSAttributedString *attributedSeedString, CGSize textContainerSize);
+extern ASTextKitComponents *ASTextKitComponentsCreate(NSAttributedString *attributedSeedString, CGSize textContainerSize);
 /**
   @abstract Returns the bounding size for the text view's text.
   @param components The TextKit components to calculate the constrained size of the text for.
   @param constrainedWidth The constraining width to be used during text-sizing. Usually, this value should be the receiver's calculated size.
   @result A CGSize representing the bounding size for the receiver's text.
  */
-extern CGSize ASTextKitComponentsSizeForConstrainedWidth(ASTextKitComponents components, CGFloat constrainedWidth);
+extern CGSize ASTextKitComponentsSizeForConstrainedWidth(ASTextKitComponents *components, CGFloat constrainedWidth);

AsyncDisplayKit/Details/ASTextNodeTextKitHelpers.mm

@@ -8,9 +8,13 @@
 
 #import "ASTextNodeTextKitHelpers.h"
 
+@implementation ASTextKitComponents
+
+@end
+
 #pragma mark - Convenience
 
-CGSize ASTextKitComponentsSizeForConstrainedWidth(ASTextKitComponents components, CGFloat constrainedWidth)
+CGSize ASTextKitComponentsSizeForConstrainedWidth(ASTextKitComponents *components, CGFloat constrainedWidth)
 {
   // If our text-view's width is already the constrained width, we can use our existing TextKit stack for this sizing calculation.
   // Otherwise, we create a temporary stack to size for `constrainedWidth`.
@@ -25,9 +29,9 @@ CGSize ASTextKitComponentsSizeForConstrainedWidth(ASTextKitComponents components
   return textSize;
 }
 
-ASTextKitComponents ASTextKitComponentsCreate(NSAttributedString *attributedSeedString, CGSize textContainerSize)
+ASTextKitComponents *ASTextKitComponentsCreate(NSAttributedString *attributedSeedString, CGSize textContainerSize)
 {
-  ASTextKitComponents components;
+  ASTextKitComponents *components = [[ASTextKitComponents alloc] init];
 
   // Create the TextKit component stack with our default configuration.
   components.textStorage = (attributedSeedString ? [[NSTextStorage alloc] initWithAttributedString:attributedSeedString] : [[NSTextStorage alloc] init]);

AsyncDisplayKitTests/ASTextNodeWordKernerTests.mm

@@ -17,7 +17,7 @@
 @interface ASTextNodeWordKernerTests : XCTestCase
 
 @property (nonatomic, readwrite, strong) ASTextNodeWordKerner *layoutManagerDelegate;
-@property (nonatomic, readwrite, assign) ASTextKitComponents components;
+@property (nonatomic, readwrite, assign) ASTextKitComponents *components;
 @property (nonatomic, readwrite, copy) NSAttributedString *attributedString;
 
 @end