Move drawing parameters in ASTextNode and ASImageNode to structs

AsyncDisplayKit/ASImageNode.mm

@@ -26,46 +26,18 @@
 #import "ASInternalHelpers.h"
 #import "ASEqualityHelpers.h"
 
-@interface _ASImageNodeDrawParameters : NSObject
+struct ASImageNodeDrawParameters {
-
+  BOOL opaque;
-@property (nonatomic, retain) UIImage *image;
+  CGRect bounds;
-@property (nonatomic, assign) BOOL opaque;
+  CGFloat contentsScale;
-@property (nonatomic, assign) CGRect bounds;
+  UIColor *backgroundColor;
-@property (nonatomic, assign) CGFloat contentsScale;
+  UIViewContentMode contentMode;
-@property (nonatomic, strong) UIColor *backgroundColor;
+  BOOL cropEnabled;
-@property (nonatomic, assign) UIViewContentMode contentMode;
+  BOOL forceUpscaling;
-
+  CGRect cropRect;
-@end
+  CGRect cropDisplayBounds;
-
+  asimagenode_modification_block_t imageModificationBlock;
-// TODO: eliminate explicit parameters with a set of keys copied from the node
+};
-@implementation _ASImageNodeDrawParameters
-
-- (instancetype)initWithImage:(UIImage *)image
-                       bounds:(CGRect)bounds
-                       opaque:(BOOL)opaque
-                contentsScale:(CGFloat)contentsScale
-              backgroundColor:(UIColor *)backgroundColor
-                  contentMode:(UIViewContentMode)contentMode
-{
-  if (!(self = [self init]))
-    return nil;
-
-  _image = image;
-  _opaque = opaque;
-  _bounds = bounds;
-  _contentsScale = contentsScale;
-  _backgroundColor = backgroundColor;
-  _contentMode = contentMode;
-
-  return self;
-}
-
-- (NSString *)description
-{
-  return [NSString stringWithFormat:@"<%@ : %p opaque:%@ bounds:%@ contentsScale:%.2f backgroundColor:%@ contentMode:%@>", [self class], self, @(self.opaque), NSStringFromCGRect(self.bounds), self.contentsScale, self.backgroundColor, ASDisplayNodeNSStringFromUIContentMode(self.contentMode)];
-}
-
-@end
 
 @implementation ASImageNode
 {
@@ -75,18 +47,22 @@
   void (^_displayCompletionBlock)(BOOL canceled);
   ASDN::RecursiveMutex _imageLock;
   
+  // Drawing
+  ASImageNodeDrawParameters _drawParameter;
+  ASTextNode *_debugLabelNode;
+  
   // Cropping.
   BOOL _cropEnabled; // Defaults to YES.
   BOOL _forceUpscaling; //Defaults to NO.
   CGRect _cropRect; // Defaults to CGRectMake(0.5, 0.5, 0, 0)
-  CGRect _cropDisplayBounds;
+  CGRect _cropDisplayBounds; // Defaults to CGRectNull
-  
-  ASTextNode *_debugLabelNode;
 }
 
 @synthesize image = _image;
 @synthesize imageModificationBlock = _imageModificationBlock;
 
+#pragma mark - NSObject
+
 - (instancetype)init
 {
   if (!(self = [super init]))
@@ -124,6 +100,8 @@
   return nil;
 }
 
+#pragma mark - Layout and Sizing
+
 - (CGSize)calculateSizeThatFits:(CGSize)constrainedSize
 {
   ASDN::MutexLocker l(_imageLock);
@@ -136,6 +114,8 @@
     return CGSizeZero;
 }
 
+#pragma mark - Setter / Getter
+
 - (void)setImage:(UIImage *)image
 {
   _imageLock.lock();
@@ -177,54 +157,72 @@
   self.placeholderEnabled = placeholderColor != nil;
 }
 
+#pragma mark - Drawing
+
 - (NSObject *)drawParametersForAsyncLayer:(_ASDisplayLayer *)layer
 {
-  return [[_ASImageNodeDrawParameters alloc] initWithImage:self.image
+  ASDN::MutexLocker l(_imageLock);
-                                                    bounds:self.bounds
+  
-                                                    opaque:self.opaque
+  _drawParameter = {
-                                             contentsScale:self.contentsScaleForDisplay
+    .bounds = self.bounds,
-                                           backgroundColor:self.backgroundColor
+    .opaque = self.opaque,
-                                               contentMode:self.contentMode];
+    .contentsScale = _contentsScaleForDisplay,
+    .backgroundColor = self.backgroundColor,
+    .contentMode = self.contentMode,
+    .cropEnabled = _cropEnabled,
+    .forceUpscaling = _forceUpscaling,
+    .cropRect = _cropRect,
+    .cropDisplayBounds = _cropDisplayBounds,
+    .imageModificationBlock = _imageModificationBlock
+  };
+  
+  return nil;
 }
 
 - (NSDictionary *)debugLabelAttributes
 {
-  return @{ NSFontAttributeName: [UIFont systemFontOfSize:15.0],
+  return @{
-            NSForegroundColorAttributeName: [UIColor redColor] };
+    NSFontAttributeName: [UIFont systemFontOfSize:15.0],
+    NSForegroundColorAttributeName: [UIColor redColor]
+  };
 }
 
-- (UIImage *)displayWithParameters:(_ASImageNodeDrawParameters *)parameters isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled
+- (UIImage *)displayWithParameters:(id<NSObject> *)parameter isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled
 {
-  UIImage *image = parameters.image;
+  UIImage *image = self.image;
-  if (!image) {
+  if (image == nil) {
     return nil;
   }
   
+  CGRect drawParameterBounds    = CGRectZero;
   BOOL forceUpscaling           = NO;
-  BOOL cropEnabled              = NO;
+  BOOL cropEnabled              = YES;
-  BOOL isOpaque                 = parameters.opaque;
+  BOOL isOpaque                 = NO;
-  UIColor *backgroundColor      = parameters.backgroundColor;
+  UIColor *backgroundColor      = nil;
-  UIViewContentMode contentMode = parameters.contentMode;
+  UIViewContentMode contentMode = UIViewContentModeScaleAspectFill;
   CGFloat contentsScale         = 0.0;
   CGRect cropDisplayBounds      = CGRectZero;
   CGRect cropRect               = CGRectZero;
   asimagenode_modification_block_t imageModificationBlock;
-  
+
+  ASDN::MutexLocker l(_imageLock);
   {
-    ASDN::MutexLocker l(_imageLock);
+    ASImageNodeDrawParameters drawParameter = _drawParameter;
     
-    // FIXME: There is a small risk of these values changing between the main thread creation of drawParameters, and the execution of this method.
+    drawParameterBounds       = drawParameter.bounds;
-    // We should package these up into the draw parameters object.  Might be easiest to create a struct for the non-objects and make it one property.
+    forceUpscaling            = drawParameter.forceUpscaling;
-    cropEnabled = _cropEnabled;
+    cropEnabled               = drawParameter.cropEnabled;
-    forceUpscaling = _forceUpscaling;
+    isOpaque                  = drawParameter.opaque;
-    contentsScale = _contentsScaleForDisplay;
+    backgroundColor           = drawParameter.backgroundColor;
-    cropDisplayBounds = _cropDisplayBounds;
+    contentMode               = drawParameter.contentMode;
-    cropRect = _cropRect;
+    contentsScale             = drawParameter.contentsScale;
-    imageModificationBlock = _imageModificationBlock;
+    cropDisplayBounds         = drawParameter.cropDisplayBounds;
+    cropRect                  = drawParameter.cropRect;
+    imageModificationBlock    = drawParameter.imageModificationBlock;
   }
   
   BOOL hasValidCropBounds = cropEnabled && !CGRectIsNull(cropDisplayBounds) && !CGRectIsEmpty(cropDisplayBounds);
-  CGRect bounds = (hasValidCropBounds ? cropDisplayBounds : parameters.bounds);
+  CGRect bounds = (hasValidCropBounds ? cropDisplayBounds : drawParameterBounds);
   
   ASDisplayNodeContextModifier preContextBlock = self.willDisplayNodeContentWithRenderingContext;
   ASDisplayNodeContextModifier postContextBlock = self.didDisplayNodeContentWithRenderingContext;
@@ -359,7 +357,6 @@
   }
 }
 
-#pragma mark -
 - (void)setNeedsDisplayWithCompletion:(void (^ _Nullable)(BOOL canceled))displayCompletionBlock
 {
   if (self.displaySuspended) {
@@ -378,6 +375,7 @@
 }
 
 #pragma mark - Cropping
+
 - (BOOL)isCropEnabled
 {
   ASDN::MutexLocker l(_imageLock);
@@ -462,6 +460,7 @@
 }
 
 #pragma mark - Debug
+
 - (void)layout
 {
   [super layout];
@@ -477,6 +476,7 @@
 @end
 
 #pragma mark - Extras
+
 extern asimagenode_modification_block_t ASImageNodeRoundBorderModificationBlock(CGFloat borderWidth, UIColor *borderColor)
 {
   return ^(UIImage *originalImage) {

AsyncDisplayKit/ASTextNode.mm

@@ -32,25 +32,10 @@ static const CGFloat ASTextNodeHighlightLightOpacity = 0.11;
 static const CGFloat ASTextNodeHighlightDarkOpacity = 0.22;
 static NSString *ASTextNodeTruncationTokenAttributeName = @"ASTextNodeTruncationAttribute";
 
-@interface ASTextNodeDrawParameters : NSObject
+struct ASTextNodeDrawParameter {
-
+  CGRect bounds;
-@property (nonatomic, assign, readonly) CGRect bounds;
+  UIColor *backgroundColor;
-@property (nonatomic, strong, readonly) UIColor *backgroundColor;
+};
-
-@end
-
-@implementation ASTextNodeDrawParameters
-
-- (instancetype)initWithBounds:(CGRect)bounds backgroundColor:(UIColor *)backgroundColor
-{
-  if (self = [super init]) {
-    _bounds = bounds;
-    _backgroundColor = backgroundColor;
-  }
-  return self;
-}
-
-@end
 
 @interface ASTextNode () <UIGestureRecognizerDelegate, NSLayoutManagerDelegate>
 
@@ -78,6 +63,8 @@ static NSString *ASTextNodeTruncationTokenAttributeName = @"ASTextNodeTruncation
 
   ASTextKitRenderer *_renderer;
 
+  ASTextNodeDrawParameter _drawParameter;
+
   UILongPressGestureRecognizer *_longPressGestureRecognizer;
 }
 @dynamic placeholderEnabled;
@@ -431,27 +418,37 @@ static NSArray *DefaultLinkAttributeNames = @[ NSLinkAttributeName ];
 
 #pragma mark - Drawing
 
-- (void)drawRect:(CGRect)bounds withParameters:(ASTextNodeDrawParameters *)parameters isCancelled:(asdisplaynode_iscancelled_block_t)isCancelledBlock isRasterizing:(BOOL)isRasterizing
+- (NSObject *)drawParametersForAsyncLayer:(_ASDisplayLayer *)layer
+{
+  _drawParameter = {
+    .backgroundColor = self.backgroundColor,
+    .bounds = self.bounds
+  };
+  return nil;
+}
+
+- (void)drawRect:(CGRect)bounds withParameters:(id <NSObject>)p isCancelled:(asdisplaynode_iscancelled_block_t)isCancelledBlock isRasterizing:(BOOL)isRasterizing;
 {
   std::lock_guard<std::recursive_mutex> l(_textLock);
+
+  ASTextNodeDrawParameter drawParameter = _drawParameter;
+  CGRect drawParameterBounds = drawParameter.bounds;
+  UIColor *backgroundColor = isRasterizing ? nil : drawParameter.backgroundColor;
   
   CGContextRef context = UIGraphicsGetCurrentContext();
   ASDisplayNodeAssert(context, @"This is no good without a context.");
   
   CGContextSaveGState(context);
   
-  ASTextKitRenderer *renderer = [self _rendererWithBounds:parameters.bounds];
+  ASTextKitRenderer *renderer = [self _rendererWithBounds:drawParameterBounds];
   UIEdgeInsets shadowPadding = [self shadowPaddingWithRenderer:renderer];
-  CGPoint boundsOrigin = parameters.bounds.origin;
+  CGPoint boundsOrigin = drawParameterBounds.origin;
   CGPoint textOrigin = CGPointMake(boundsOrigin.x - shadowPadding.left, boundsOrigin.y - shadowPadding.top);
   
   // Fill background
-  if (!isRasterizing) {
+  if (backgroundColor != nil) {
-    UIColor *backgroundColor = parameters.backgroundColor;
+    [backgroundColor setFill];
-    if (backgroundColor) {
+    UIRectFillUsingBlendMode(CGContextGetClipBoundingBox(context), kCGBlendModeCopy);
-      [backgroundColor setFill];
-      UIRectFillUsingBlendMode(CGContextGetClipBoundingBox(context), kCGBlendModeCopy);
-    }
   }
   
   // Draw shadow
@@ -464,11 +461,6 @@ static NSArray *DefaultLinkAttributeNames = @[ NSLinkAttributeName ];
   CGContextRestoreGState(context);
 }
 
-- (NSObject *)drawParametersForAsyncLayer:(_ASDisplayLayer *)layer
-{
-  return [[ASTextNodeDrawParameters alloc] initWithBounds:self.threadSafeBounds backgroundColor:self.backgroundColor];
-}
-
 #pragma mark - Attributes
 
 - (id)linkAttributeValueAtPoint:(CGPoint)point