addressed some comments

AsyncDisplayKit/ASCollectionNode.mm

@@ -245,6 +245,6 @@
   [self.view reloadDataImmediately];
 }
 
-ASDisplayTraitsCollectionTableSetEnvironmentState
+ASEnvironmentDisplayTraitsCollectionTableSetEnvironmentState
 
 @end

AsyncDisplayKit/ASDisplayNode.mm

@@ -2709,12 +2709,12 @@ static const char *ASDisplayNodeDrawingPriorityKey = "ASDrawingPriority";
 
 - (BOOL)supportsUpwardPropagation
 {
-  return ASEnvironmentStateUpwardPropagationEnabled();
+  return ASEnvironmentStatePropagationEnabled();
 }
 
-- (BOOL)supportsDownwardPropagation
+- (BOOL)supportsTraitsCollectionPropagation
 {
-  return ASEnvironmentStateDownwardPropagationEnabled();
+  return ASEnvironmentStateTraitCollectionPropagationEnabled();
 }
 
 ASEnvironmentLayoutOptionsForwarding

AsyncDisplayKit/ASTableNode.mm

@@ -159,6 +159,6 @@
   [self.view clearFetchedData];
 }
 
-ASDisplayTraitsCollectionTableSetEnvironmentState
+ASEnvironmentDisplayTraitsCollectionTableSetEnvironmentState
 
 @end

AsyncDisplayKit/ASViewController.h

@@ -11,8 +11,8 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-typedef ASDisplayTraits (^ASDisplayTraitsForTraitCollectionBlock)(UITraitCollection *traitCollection);
+typedef ASEnvironmentDisplayTraits (^ASEnvironmentDisplayTraitsForTraitCollectionBlock)(UITraitCollection *traitCollection);
-typedef ASDisplayTraits (^ASDisplayTraitsForTraitWindowSizeBlock)(CGSize windowSize);
+typedef ASEnvironmentDisplayTraits (^ASEnvironmentDisplayTraitsForTraitWindowSizeBlock)(CGSize windowSize);
 
 @interface ASViewController<__covariant DisplayNodeType : ASDisplayNode *> : UIViewController
 
@@ -25,12 +25,12 @@ typedef ASDisplayTraits (^ASDisplayTraitsForTraitWindowSizeBlock)(CGSize windowS
 /**
  * Set this block to customize the ASDisplayTraits returned when the VC transitions to the given traitCollection.
  */
-@property (nonatomic, copy) ASDisplayTraitsForTraitCollectionBlock overrideDisplayTraitsWithTraitCollection;
+@property (nonatomic, copy) ASEnvironmentDisplayTraitsForTraitCollectionBlock overrideDisplayTraitsWithTraitCollection;
 
 /**
  * Set this block to customize the ASDisplayTraits returned when the VC transitions to the given window size.
  */
-@property (nonatomic, copy) ASDisplayTraitsForTraitWindowSizeBlock overrideDisplayTraitsWithWindowSize;
+@property (nonatomic, copy) ASEnvironmentDisplayTraitsForTraitWindowSizeBlock overrideDisplayTraitsWithWindowSize;
 
 /**
  * @abstract Passthrough property to the the .interfaceState of the node.

AsyncDisplayKit/ASViewController.mm

@@ -143,18 +143,18 @@
 
 #pragma mark - ASDisplayTraits
 
-- (ASDisplayTraits)displayTraitsForTraitCollection:(UITraitCollection *)traitCollection
+- (ASEnvironmentDisplayTraits)displayTraitsForTraitCollection:(UITraitCollection *)traitCollection
 {
   if (self.overrideDisplayTraitsWithTraitCollection) {
     return self.overrideDisplayTraitsWithTraitCollection(traitCollection);
   }
   
-  ASDisplayTraits displayTraits = ASDisplayTraitsFromUITraitCollection(traitCollection);
+  ASEnvironmentDisplayTraits displayTraits = ASEnvironmentDisplayTraitsFromUITraitCollection(traitCollection);
   displayTraits.displayContext = _displayTraitsContext;
   return displayTraits;
 }
 
-- (ASDisplayTraits)displayTraitsForWindowSize:(CGSize)windowSize
+- (ASEnvironmentDisplayTraits)displayTraitsForWindowSize:(CGSize)windowSize
 {
   if (self.overrideDisplayTraitsWithWindowSize) {
     return self.overrideDisplayTraitsWithWindowSize(windowSize);
@@ -162,12 +162,12 @@
   return self.node.environmentState.displayTraits;
 }
 
-- (void)progagateNewDisplayTraits:(ASDisplayTraits)displayTraits
+- (void)progagateNewDisplayTraits:(ASEnvironmentDisplayTraits)displayTraits
 {
   ASEnvironmentState environmentState = self.node.environmentState;
-  ASDisplayTraits oldDisplayTraits = environmentState.displayTraits;
+  ASEnvironmentDisplayTraits oldDisplayTraits = environmentState.displayTraits;
   
-  if (ASDisplayTraitsIsEqualToASDisplayTraits(displayTraits, oldDisplayTraits) == NO) {
+  if (ASEnvironmentDisplayTraitsIsEqualToASEnvironmentDisplayTraits(displayTraits, oldDisplayTraits) == NO) {
     environmentState.displayTraits = displayTraits;
     [self.node setEnvironmentState:environmentState];
     [self.node setNeedsLayout];
@@ -183,7 +183,7 @@
 {
   [super traitCollectionDidChange:previousTraitCollection];
   
-  ASDisplayTraits displayTraits = [self displayTraitsForTraitCollection:self.traitCollection];
+  ASEnvironmentDisplayTraits displayTraits = [self displayTraitsForTraitCollection:self.traitCollection];
   [self progagateNewDisplayTraits:displayTraits];
 }
 
@@ -191,7 +191,7 @@
 {
   [super willTransitionToTraitCollection:newCollection withTransitionCoordinator:coordinator];
   
-  ASDisplayTraits displayTraits = [self displayTraitsForTraitCollection:self.traitCollection];
+  ASEnvironmentDisplayTraits displayTraits = [self displayTraitsForTraitCollection:self.traitCollection];
   [self progagateNewDisplayTraits:displayTraits];
 }
 
@@ -199,7 +199,7 @@
 {
   [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
   
-  ASDisplayTraits displayTraits = [self displayTraitsForWindowSize:size];
+  ASEnvironmentDisplayTraits displayTraits = [self displayTraitsForWindowSize:size];
   [self progagateNewDisplayTraits:displayTraits];
 }
 

AsyncDisplayKit/Details/ASEnvironment.h

@@ -61,9 +61,9 @@ typedef struct ASEnvironmentHierarchyState {
   unsigned layoutPending:1; // = NO
 } ASEnvironmentHierarchyState;
 
-#pragma mark - ASDisplayTraits
+#pragma mark - ASEnvironmentDisplayTraits
 
-typedef struct ASDisplayTraits {
+typedef struct ASEnvironmentDisplayTraits {
   CGFloat displayScale;
   UIUserInterfaceSizeClass horizontalSizeClass;
   UIUserInterfaceIdiom userInterfaceIdiom;
@@ -86,19 +86,19 @@ typedef struct ASDisplayTraits {
   // which will propagate a nil displayContext to its subnodes.
   //__unsafe_unretained id displayContext;
   id __unsafe_unretained displayContext;
-} ASDisplayTraits;
+} ASEnvironmentDisplayTraits;
 
 extern void ASDisplayTraitsClearDisplayContext(id<ASEnvironment> rootEnvironment);
 
-extern ASDisplayTraits ASDisplayTraitsFromUITraitCollection(UITraitCollection *traitCollection);
+extern ASEnvironmentDisplayTraits ASEnvironmentDisplayTraitsFromUITraitCollection(UITraitCollection *traitCollection);
-extern BOOL ASDisplayTraitsIsEqualToASDisplayTraits(ASDisplayTraits displayTraits0, ASDisplayTraits displayTraits1);
+extern BOOL ASEnvironmentDisplayTraitsIsEqualToASEnvironmentDisplayTraits(ASEnvironmentDisplayTraits displayTraits0, ASEnvironmentDisplayTraits displayTraits1);
 
 #pragma mark - ASEnvironmentState
 
 typedef struct ASEnvironmentState {
   struct ASEnvironmentHierarchyState hierarchyState;
   struct ASEnvironmentLayoutOptionsState layoutOptionsState;
-  struct ASDisplayTraits displayTraits;
+  struct ASEnvironmentDisplayTraits displayTraits;
 } ASEnvironmentState;
 extern ASEnvironmentState ASEnvironmentStateMakeDefault();
 
@@ -129,7 +129,7 @@ ASDISPLAYNODE_EXTERN_C_END
 - (BOOL)supportsUpwardPropagation;
 
 /// Classes should implement this method and return YES / NO dependent if downware propagation is enabled or not
-- (BOOL)supportsDownwardPropagation;
+- (BOOL)supportsTraitsCollectionPropagation;
 
 @end
 
@@ -140,13 +140,13 @@ ASDISPLAYNODE_EXTERN_C_END
 // If there is any new downward propagating state, it should be added to this define.
 //
 // This logic is used in both ASCollectionNode and ASTableNode
-#define ASDisplayTraitsCollectionTableSetEnvironmentState \
+#define ASEnvironmentDisplayTraitsCollectionTableSetEnvironmentState \
 - (void)setEnvironmentState:(ASEnvironmentState)environmentState\
 {\
-  ASDisplayTraits oldDisplayTraits = self.environmentState.displayTraits;\
+  ASEnvironmentDisplayTraits oldDisplayTraits = self.environmentState.displayTraits;\
   [super setEnvironmentState:environmentState];\
-  ASDisplayTraits currentDisplayTraits = environmentState.displayTraits;\
+  ASEnvironmentDisplayTraits currentDisplayTraits = environmentState.displayTraits;\
-  if (ASDisplayTraitsIsEqualToASDisplayTraits(currentDisplayTraits, oldDisplayTraits) == NO) {\
+  if (ASEnvironmentDisplayTraitsIsEqualToASEnvironmentDisplayTraits(currentDisplayTraits, oldDisplayTraits) == NO) {\
     NSArray<NSArray <ASCellNode *> *> *completedNodes = [self.view.dataController completedNodes];\
     for (NSArray *sectionArray in completedNodes) {\
       for (ASCellNode *cellNode in sectionArray) {\

AsyncDisplayKit/Details/ASEnvironment.mm

@@ -28,7 +28,7 @@ ASEnvironmentHierarchyState _ASEnvironmentHierarchyStateMakeDefault()
 extern void ASDisplayTraitsClearDisplayContext(id<ASEnvironment> rootEnvironment)
 {
   ASEnvironmentState envState = [rootEnvironment environmentState];
-  ASDisplayTraits displayTraits = envState.displayTraits;
+  ASEnvironmentDisplayTraits displayTraits = envState.displayTraits;
   displayTraits.displayContext = nil;
   envState.displayTraits = displayTraits;
   [rootEnvironment setEnvironmentState:envState];
@@ -38,16 +38,16 @@ extern void ASDisplayTraitsClearDisplayContext(id<ASEnvironment> rootEnvironment
   }
 }
 
-ASDisplayTraits _ASDisplayTraitsMakeDefault()
+ASEnvironmentDisplayTraits _ASEnvironmentDisplayTraitsMakeDefault()
 {
-  return (ASDisplayTraits) {
+  return (ASEnvironmentDisplayTraits) {
     // Default values can be defined in here
   };
 }
 
-ASDisplayTraits ASDisplayTraitsFromUITraitCollection(UITraitCollection *traitCollection)
+ASEnvironmentDisplayTraits ASEnvironmentDisplayTraitsFromUITraitCollection(UITraitCollection *traitCollection)
 {  
-  return (ASDisplayTraits) {
+  return (ASEnvironmentDisplayTraits) {
     .displayScale = traitCollection.displayScale,
     .horizontalSizeClass = traitCollection.horizontalSizeClass,
     .userInterfaceIdiom = traitCollection.userInterfaceIdiom,
@@ -56,7 +56,7 @@ ASDisplayTraits ASDisplayTraitsFromUITraitCollection(UITraitCollection *traitCol
   };
 }
 
-BOOL ASDisplayTraitsIsEqualToASDisplayTraits(ASDisplayTraits displayTraits0, ASDisplayTraits displayTraits1)
+BOOL ASEnvironmentDisplayTraitsIsEqualToASEnvironmentDisplayTraits(ASEnvironmentDisplayTraits displayTraits0, ASEnvironmentDisplayTraits displayTraits1)
 {
   return
   displayTraits0.verticalSizeClass == displayTraits1.verticalSizeClass &&
@@ -71,7 +71,7 @@ ASEnvironmentState ASEnvironmentStateMakeDefault()
   return (ASEnvironmentState) {
     .layoutOptionsState = _ASEnvironmentLayoutOptionsStateMakeDefault(),
     .hierarchyState = _ASEnvironmentHierarchyStateMakeDefault(),
-    .displayTraits = _ASDisplayTraitsMakeDefault()
+    .displayTraits = _ASEnvironmentDisplayTraitsMakeDefault()
   };
 }
 

AsyncDisplayKit/Layout/ASLayoutSpec.mm

@@ -80,7 +80,7 @@
 
     id<ASLayoutable> finalLayoutable = [child finalLayoutable];
     if (finalLayoutable != child) {
-      if (ASEnvironmentStateUpwardPropagationEnabled()) {
+      if (ASEnvironmentStatePropagationEnabled()) {
         ASEnvironmentStatePropagateUp(finalLayoutable, child.environmentState.layoutOptionsState);
       } else {
         // If state propagation is not enabled the layout options state needs to be copied manually
@@ -183,12 +183,12 @@
 // the specifications that are known to have more than one.
 - (BOOL)supportsUpwardPropagation
 {
-  return ASEnvironmentStateUpwardPropagationEnabled();
+  return ASEnvironmentStatePropagationEnabled();
 }
 
-- (BOOL)supportsDownwardPropagation
+- (BOOL)supportsTraitsCollectionPropagation
 {
-  return ASEnvironmentStateDownwardPropagationEnabled();
+  return ASEnvironmentStateTraitCollectionPropagationEnabled();
 }
 
 - (void)propagateUpLayoutable:(id<ASLayoutable>)layoutable

AsyncDisplayKit/Layout/ASLayoutablePrivate.h

@@ -79,7 +79,7 @@ extern void ASLayoutableClearCurrentContext();
 #define ASEnvironmentLayoutOptionsForwarding \
 - (void)propagateUpLayoutOptionsState\
 {\
-  if (!ASEnvironmentStateUpwardPropagationEnabled()) {\
+  if (!ASEnvironmentStatePropagationEnabled()) {\
     return;\
   }\
   id<ASEnvironment> parent = [self parent];\

AsyncDisplayKit/Private/ASEnvironmentInternal.h

@@ -12,8 +12,8 @@
 
 #pragma once
 
-BOOL ASEnvironmentStateUpwardPropagationEnabled();
+BOOL ASEnvironmentStatePropagationEnabled();
-BOOL ASEnvironmentStateDownwardPropagationEnabled();
+BOOL ASEnvironmentStateTraitCollectionPropagationEnabled();
 
 
 #pragma mark - Set and get extensible values for layout options
@@ -49,8 +49,8 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environme
 static const struct ASEnvironmentHierarchyState ASEnvironmentDefaultHierarchyState = {};
 ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentHierarchyState state, ASEnvironmentStatePropagation propagation);
 
-static const struct ASDisplayTraits ASEnvironmentDefaultDisplayTraits = {};
+static const struct ASEnvironmentDisplayTraits ASEnvironmentDefaultDisplayTraits = {};
-ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASDisplayTraits state, ASEnvironmentStatePropagation propagation);
+ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentDisplayTraits state, ASEnvironmentStatePropagation propagation);
 
 
 #pragma mark - Propagation

AsyncDisplayKit/Private/ASEnvironmentInternal.mm

@@ -15,20 +15,19 @@
 //#define LOG(...) NSLog(__VA_ARGS__)
 #define LOG(...)
 
-#define AS_SUPPORT_UPWARD_PROPAGATION NO
+#define AS_SUPPORT_PROPAGATION YES
-#define AS_SUPPORT_DOWNWARD_PROPAGATION YES
+#define AS_DOES_NOT_SUPPORT_PROPAGATION NO
 
-BOOL ASEnvironmentStateUpwardPropagationEnabled()
+BOOL ASEnvironmentStatePropagationEnabled()
 {
-  return AS_SUPPORT_UPWARD_PROPAGATION;
+  return AS_DOES_NOT_SUPPORT_PROPAGATION;
 }
 
-BOOL ASEnvironmentStateDownwardPropagationEnabled()
+BOOL ASEnvironmentStateTraitCollectionPropagationEnabled()
 {
-  return AS_SUPPORT_DOWNWARD_PROPAGATION;
+  return AS_SUPPORT_PROPAGATION;
 }
 
-
 #pragma mark - Traversing an ASEnvironment Tree
 
 void ASEnvironmentPerformBlockOnObjectAndChildren(id<ASEnvironment> object, void(^block)(id<ASEnvironment> node))
@@ -120,7 +119,7 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environme
   // Merge object and layout options state
   LOG(@"Merge object and state: %@ - ASEnvironmentLayoutOptionsState", layoutOptionsState);
   
-  if (!ASEnvironmentStateUpwardPropagationEnabled() && propagation == ASEnvironmentStatePropagation::UP) {
+  if (!ASEnvironmentStatePropagationEnabled() && propagation == ASEnvironmentStatePropagation::UP) {
     return environmentState;
   }
   
@@ -195,14 +194,14 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environme
   return environmentState;
 }
 
-ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState childEnvironmentState, ASDisplayTraits parentDisplayTraits, ASEnvironmentStatePropagation propagation) {
+ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState childEnvironmentState, ASEnvironmentDisplayTraits parentDisplayTraits, ASEnvironmentStatePropagation propagation) {
-  if (propagation == ASEnvironmentStatePropagation::DOWN && !ASEnvironmentStateDownwardPropagationEnabled()) {
+  if (propagation == ASEnvironmentStatePropagation::DOWN && !ASEnvironmentStateTraitCollectionPropagationEnabled()) {
     return childEnvironmentState;
   }
   
   // Support propagate down
   if (propagation == ASEnvironmentStatePropagation::DOWN) {
-    ASDisplayTraits childDisplayTraits = childEnvironmentState.displayTraits;
+    ASEnvironmentDisplayTraits childDisplayTraits = childEnvironmentState.displayTraits;
     childDisplayTraits.horizontalSizeClass = parentDisplayTraits.horizontalSizeClass;
     childDisplayTraits.verticalSizeClass = parentDisplayTraits.verticalSizeClass;
     childDisplayTraits.userInterfaceIdiom = parentDisplayTraits.userInterfaceIdiom;

examples/DisplayTraits/Sample/CollectionViewController.m

@@ -61,7 +61,7 @@
 
 - (ASSizeRange)collectionView:(ASCollectionView *)collectionView constrainedSizeForNodeAtIndexPath:(NSIndexPath *)indexPath
 {
-  ASDisplayTraits displayTraits = self.collectionNode.environmentState.displayTraits;
+  ASEnvironmentDisplayTraits displayTraits = self.collectionNode.environmentState.displayTraits;
   
   if (displayTraits.horizontalSizeClass == UIUserInterfaceSizeClassRegular) {
     return ASSizeRangeMake(CGSizeMake(200, 120), CGSizeMake(200, 120));

examples/DisplayTraits/Sample/KittenNode.m

@@ -129,7 +129,7 @@ static const CGFloat kInnerPadding = 10.0f;
 - (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
 {
   
-  ASDisplayTraits displayTraits = self.environmentState.displayTraits;
+  ASEnvironmentDisplayTraits displayTraits = self.environmentState.displayTraits;
   
   ASStackLayoutSpec *stackSpec = [[ASStackLayoutSpec alloc] init];
   stackSpec.spacing = kInnerPadding;
@@ -152,7 +152,7 @@ static const CGFloat kInnerPadding = 10.0f;
   OverrideViewController *overrideVC = [[OverrideViewController alloc] init];
   
   overrideVC.overrideDisplayTraitsWithTraitCollection = ^(UITraitCollection *traitCollection) {
-    return (ASDisplayTraits) {
+    return (ASEnvironmentDisplayTraits) {
       .displayScale = traitCollection.displayScale,
       .horizontalSizeClass = UIUserInterfaceSizeClassCompact,
       .userInterfaceIdiom = traitCollection.userInterfaceIdiom,

examples/DisplayTraits/Sample/OverrideViewController.m

@@ -42,7 +42,7 @@ static NSString *kLinkAttributeName = @"PlaceKittenNodeLinkAttributeName";
 - (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
 {
   CGFloat pointSize = 16.f;
-  ASDisplayTraits displayTraits = self.environmentState.displayTraits;
+  ASEnvironmentDisplayTraits displayTraits = self.environmentState.displayTraits;
   if (displayTraits.horizontalSizeClass == UIUserInterfaceSizeClassRegular) {
     // This should never happen because we override the VC's display traits to always be compact.
     pointSize = 100;