[ASImageNode] More refined naming and documentation for [ASImageNode shouldShowImageScalingOverlay]

AsyncDisplayKit/ASImageNode.mm

@@ -57,10 +57,6 @@
 
 @end
 
-@interface ASImageNode ()
-@property (nonatomic, strong) ASTextNode *debugLabelNode;
-@end
-
 @implementation ASImageNode
 {
 @private
@@ -74,6 +70,8 @@
   BOOL _forceUpscaling; //Defaults to NO.
   CGRect _cropRect; // Defaults to CGRectMake(0.5, 0.5, 0, 0)
   CGRect _cropDisplayBounds;
+  
+  ASTextNode *_debugLabelNode;
 }
 
 @synthesize image = _image;
@@ -95,7 +93,7 @@
   _cropDisplayBounds = CGRectNull;
   _placeholderColor = ASDisplayNodeDefaultPlaceholderColor();
   
-  if ([ASImageNode shouldShowImageDebugOverlay]) {
+  if ([ASImageNode shouldShowImageScalingOverlay]) {
     _debugLabelNode = [[ASTextNode alloc] init];
     _debugLabelNode.layerBacked = YES;
     [self addSubnode:_debugLabelNode];
@@ -120,7 +118,6 @@
 {
   ASDN::MutexLocker l(_imageLock);
   // if a preferredFrameSize is set, call the superclass to return that instead of using the image size.
-  [_debugLabelNode measure:constrainedSize];
   if (CGSizeEqualToSize(self.preferredFrameSize, CGSizeZero) == NO)
     return [super calculateSizeThatFits:constrainedSize];
   else if (_image)
@@ -221,7 +218,6 @@
   CGSize boundsSizeInPixels = CGSizeMake(floorf(bounds.size.width * contentsScale), floorf(bounds.size.height * contentsScale));
   
   if (_debugLabelNode) {
-  //  NSLog(@"widthScale = %f, heightScale = %f", imageSizeInPixels.width / boundsSizeInPixels.width, imageSizeInPixels.height / boundsSizeInPixels.height);
     CGFloat pixelCountRatio            = (imageSizeInPixels.width * imageSizeInPixels.height) / (boundsSizeInPixels.width * boundsSizeInPixels.height);
     if (pixelCountRatio != 1.0) {
       NSString *scaleString            = [NSString stringWithFormat:@"%.2fx", pixelCountRatio];

AsyncDisplayKit/AsyncDisplayKit+Debug.h

@@ -9,13 +9,15 @@
 #import <Foundation/Foundation.h>
 #import "ASImageNode.h"
 
-@interface ASImageNode (Debug)
+@interface ASImageNode (Debugging)
 
 /**
-* Class method to enable visualization of an ASImageNode's image size. For app debugging purposes only.
-* @param enabled Specify YES to turn on this debug feature when messaging the ASImageNode class.
+* Enables an ASImageNode debug label that shows the ratio of pixels in the source image to those in
+* the displayed bounds (including cropRect).  This helps detect excessive image fetching / downscaling,
+* as well as upscaling (such as providing a URL not suitable for a Retina device).  For dev purposes only.
+* @param enabled Specify YES to show the label on all ASImageNodes with non-1.0x source-to-bounds pixel ratio.
 */
-+ (void)setImageDebugEnabled:(BOOL)enable;
-+ (BOOL)shouldShowImageDebugOverlay;
++ (void)setShouldShowImageScalingOverlay:(BOOL)show;
++ (BOOL)shouldShowImageScalingOverlay;
 
 @end

AsyncDisplayKit/AsyncDisplayKit+Debug.m

@@ -8,20 +8,19 @@
 
 #import "AsyncDisplayKit+Debug.h"
 #import "ASDisplayNode+Subclasses.h"
-#import "ASTextNode.h"
 
-static BOOL __enableImageSizeOverlay = NO;
+static BOOL __shouldShowImageScalingOverlay = NO;
 
-@implementation ASImageNode (Debug)
+@implementation ASImageNode (Debugging)
 
-+ (void)setImageDebugEnabled:(BOOL)enable;
++ (void)setShouldShowImageScalingOverlay:(BOOL)show;
 {
-  __enableImageSizeOverlay = enable;
+  __shouldShowImageScalingOverlay = show;
 }
 
-+ (BOOL)shouldShowImageDebugOverlay
++ (BOOL)shouldShowImageScalingOverlay
 {
-  return __enableImageSizeOverlay;
+  return __shouldShowImageScalingOverlay;
 }
 
 @end