facebookarchive · Adlai-Holler · Jul 8, 2016 · Jul 7, 2016 · Jul 7, 2016 · Jul 7, 2016
diff --git a/AsyncDisplayKit/ASViewController.h b/AsyncDisplayKit/ASViewController.h
@@ -27,18 +27,6 @@ typedef ASTraitCollection * _Nonnull (^ASDisplayTraitsForTraitWindowSizeBlock)(C
 
 @property (nonatomic, strong, readonly) DisplayNodeType node;
 
-/**
- *  An optional context to pass along with an ASTraitCollection.
- *  This can be used to pass any internal state to all subnodes via the ASTraitCollection that is not
- *  included in UITraitCollection. This could range from more fine-tuned size classes to a class of
- *  constants that is based upon the new trait collection.
- *
- *  Be aware that internally this context is held by a C struct which cannot retain the pointer. Therefore
- *  ASVC keeps a strong reference to the context to make sure that it stays alive. If you change this value
- *  it will propagate the change to the subnodes.
- */
-@property (nonatomic, strong) id _Nullable traitCollectionContext;
-
 /**
  * Set this block to customize the ASDisplayTraits returned when the VC transitions to the given traitCollection.
  */

diff --git a/AsyncDisplayKit/ASViewController.mm b/AsyncDisplayKit/ASViewController.mm
@@ -58,17 +58,6 @@ - (instancetype)initWithNode:(ASDisplayNode *)node
   return self;
 }
 
-- (void)dealloc
-{
-  if (_traitCollectionContext != nil) {
-    // The setter will iterate through the VC's subnodes and replace the traitCollectionContext in their ASEnvironmentTraitCollection with nil.
-    // Since the VC holds the only strong reference to this context and we are in the process of destroying
-    // the VC, all the references in the subnodes will be unsafe unless we nil them out. More than likely all the subnodes will be dealloc'ed
-    // as part of the VC being dealloc'ed, but this is just to make extra sure.
-    self.traitCollectionContext = nil;
-  }
-}
-
 - (void)loadView
 {
   ASDisplayNodeAssertTrue(!_node.layerBacked);
@@ -199,37 +188,26 @@ - (ASInterfaceState)interfaceState
 
 #pragma mark - ASEnvironmentTraitCollection
 
-- (void)setTraitCollectionContext:(id)traitCollectionContext
-{
-  if (_traitCollectionContext != traitCollectionContext) {
-    // nil out the displayContext in the subnodes so they aren't hanging around with a dealloc'ed pointer don't set
-    // the new context yet as this will cause ASEnvironmentTraitCollectionIsEqualToASEnvironmentTraitCollection to fail
-    ASEnvironmentTraitCollectionUpdateDisplayContext(self.node, nil);
-
-    _traitCollectionContext = traitCollectionContext;
-  }
-}
-
 - (ASEnvironmentTraitCollection)environmentTraitCollectionForUITraitCollection:(UITraitCollection *)traitCollection
 {
   if (self.overrideDisplayTraitsWithTraitCollection) {
     ASTraitCollection *asyncTraitCollection = self.overrideDisplayTraitsWithTraitCollection(traitCollection);
-    self.traitCollectionContext = asyncTraitCollection.traitCollectionContext;
     return [asyncTraitCollection environmentTraitCollection];
   }
 
+  ASDisplayNodeAssertMainThread();
   ASEnvironmentTraitCollection asyncTraitCollection = ASEnvironmentTraitCollectionFromUITraitCollection(traitCollection);
-  asyncTraitCollection.displayContext = self.traitCollectionContext;
+  asyncTraitCollection.containerSize = self.view.frame.size;
   return asyncTraitCollection;
 }
 
 - (ASEnvironmentTraitCollection)environmentTraitCollectionForWindowSize:(CGSize)windowSize
 {
   if (self.overrideDisplayTraitsWithWindowSize) {
     ASTraitCollection *traitCollection = self.overrideDisplayTraitsWithWindowSize(windowSize);
-    self.traitCollectionContext = traitCollection.traitCollectionContext;
     return [traitCollection environmentTraitCollection];
   }
+  self.node.environmentTraitCollection.containerSize = windowSize;
   return self.node.environmentTraitCollection;
 }
 
@@ -255,17 +233,13 @@ - (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection
   [super traitCollectionDidChange:previousTraitCollection];
 
   ASEnvironmentTraitCollection environmentTraitCollection = [self environmentTraitCollectionForUITraitCollection:self.traitCollection];
+  environmentTraitCollection.containerSize = self.view.bounds.size;
   [self progagateNewEnvironmentTraitCollection:environmentTraitCollection];
 }
 
-- (void)willTransitionToTraitCollection:(UITraitCollection *)newCollection withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
-{
-  [super willTransitionToTraitCollection:newCollection withTransitionCoordinator:coordinator];
-
-  ASEnvironmentTraitCollection environmentTraitCollection = [self environmentTraitCollectionForUITraitCollection:newCollection];
-  [self progagateNewEnvironmentTraitCollection:environmentTraitCollection];
-}
-
+// Note: We don't override willTransitionToTraitCollection:withTransitionCoordinator: because viewWillTransitionToSize:withTransitionCoordinator: will also called
+// called in all these cases. However, there are cases where viewWillTransitionToSize:withTransitionCoordinator: but willTransitionToTraitCollection:withTransitionCoordinator:
+// is not.
 - (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
 {
   [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];

diff --git a/AsyncDisplayKit/Details/ASEnvironment.h b/AsyncDisplayKit/Details/ASEnvironment.h
@@ -69,25 +69,9 @@ typedef struct ASEnvironmentTraitCollection {
   UIUserInterfaceIdiom userInterfaceIdiom;
   UIUserInterfaceSizeClass verticalSizeClass;
   UIForceTouchCapability forceTouchCapability;
-
-  // WARNING:
-  // This pointer is in a C struct and therefore not managed by ARC. It is
-  // an unsafe unretained pointer, so when you dereference it you better be
-  // sure that it is valid.
-  //
-  // Use displayContext when you wish to pass view context specific data along with the
-  // display traits to subnodes. This should be a piece of data owned by an
-  // ASViewController, which will ensure that the data is still valid when laying out
-  // its subviews. When the VC is dealloc'ed, the displayContext it created will also
-  // be dealloced but any subnodes that are hanging around (why would they be?) will now
-  // have a displayContext that points to a bad pointer.
-  //
-  // As an added precaution ASDisplayTraitsClearDisplayContext is called from ASVC's desctructor
-  // which will propagate a nil displayContext to its subnodes.
-  id __unsafe_unretained displayContext;
-} ASEnvironmentTraitCollection;
 
-extern void ASEnvironmentTraitCollectionUpdateDisplayContext(id<ASEnvironment> rootEnvironment, id _Nullable context);
+  CGSize containerSize;
+} ASEnvironmentTraitCollection;
 
 extern ASEnvironmentTraitCollection ASEnvironmentTraitCollectionFromUITraitCollection(UITraitCollection *traitCollection);
 extern BOOL ASEnvironmentTraitCollectionIsEqualToASEnvironmentTraitCollection(ASEnvironmentTraitCollection lhs, ASEnvironmentTraitCollection rhs);
@@ -165,14 +149,11 @@ ASDISPLAYNODE_EXTERN_C_END
   if (ASEnvironmentTraitCollectionIsEqualToASEnvironmentTraitCollection(currentTraits, oldTraits) == NO) {\
     /* Must dispatch to main for self.view && [self.view.dataController completedNodes]*/ \
     ASPerformBlockOnMainThread(^{\
-      BOOL needsLayout = (oldTraits.displayContext == currentTraits.displayContext) || currentTraits.displayContext != nil;\
       NSArray<NSArray <ASCellNode *> *> *completedNodes = [self.view.dataController completedNodes];\
       for (NSArray *sectionArray in completedNodes) {\
         for (ASCellNode *cellNode in sectionArray) {\
           ASEnvironmentStatePropagateDown(cellNode, currentTraits);\
-          if (needsLayout) {\
-            [cellNode setNeedsLayout];\
-          }\
+          [cellNode setNeedsLayout];\
         }\
       }\
     });\

diff --git a/AsyncDisplayKit/Details/ASEnvironment.mm b/AsyncDisplayKit/Details/ASEnvironment.mm
@@ -26,23 +26,11 @@ ASEnvironmentHierarchyState _ASEnvironmentHierarchyStateMakeDefault()
   };
 }
 
-extern void ASEnvironmentTraitCollectionUpdateDisplayContext(id<ASEnvironment> rootEnvironment, id context)
-{
-  ASEnvironmentState envState = [rootEnvironment environmentState];
-  ASEnvironmentTraitCollection environmentTraitCollection = envState.environmentTraitCollection;
-  environmentTraitCollection.displayContext = context;
-  envState.environmentTraitCollection = environmentTraitCollection;
-  [rootEnvironment setEnvironmentState:envState];
-
-  for (id<ASEnvironment> child in [rootEnvironment children]) {
-    ASEnvironmentStatePropagateDown(child, environmentTraitCollection);
-  }
-}
-
 ASEnvironmentTraitCollection _ASEnvironmentTraitCollectionMakeDefault()
 {
   return (ASEnvironmentTraitCollection) {
     // Default values can be defined in here
+    .containerSize = CGSizeZero,
   };
 }
 
@@ -69,7 +57,7 @@ BOOL ASEnvironmentTraitCollectionIsEqualToASEnvironmentTraitCollection(ASEnviron
     lhs.displayScale == rhs.displayScale &&
     lhs.userInterfaceIdiom == rhs.userInterfaceIdiom &&
     lhs.forceTouchCapability == rhs.forceTouchCapability &&
-    lhs.displayContext == rhs.displayContext;
+    CGSizeEqualToSize(lhs.containerSize, rhs.containerSize);
 }
 
 ASEnvironmentState ASEnvironmentStateMakeDefault()

diff --git a/AsyncDisplayKit/Details/ASTraitCollection.h b/AsyncDisplayKit/Details/ASTraitCollection.h
@@ -18,35 +18,21 @@
 @property (nonatomic, assign, readonly) UIUserInterfaceIdiom userInterfaceIdiom;
 @property (nonatomic, assign, readonly) UIUserInterfaceSizeClass verticalSizeClass;
 @property (nonatomic, assign, readonly) UIForceTouchCapability forceTouchCapability;
-
-/**
- *  An optional context to pass along with an ASTraitCollection.
- *  This can be used to pass any internal state to all subnodes via the ASTraitCollection that is not
- *  included in UITraitCollection. This could range from more fine-tuned size classes to a class of
- *  constants that is based upon the new trait collection.
- *
- *  Be aware that internally this context is held by a C struct which cannot retain the pointer. 
- *  ASTraitCollection is generally a very short-lived class, existing only to provide a non-struct API
- *  to trait collections. When an ASTraitCollection is returned via one of ASViewController's 2 
- *  custom trait collection creation blocks, traitCollectionContext is assigned to the VC's traitCollectionContext.
- *  This makes sure that the VC is the owner of the context and ASEnvironmentTraitCollections will not
- *  have a reference to a dangling pointer.
- */
-@property (nonatomic, strong, readonly) id traitCollectionContext;
+@property (nonatomic, assign, readonly) CGSize containerSize;
 
 
 + (ASTraitCollection *)traitCollectionWithASEnvironmentTraitCollection:(ASEnvironmentTraitCollection)traits;
 
 + (ASTraitCollection *)traitCollectionWithUITraitCollection:(UITraitCollection *)traitCollection
-                                     traitCollectionContext:(id)traitCollectionContext;
+                                        containerSize:(CGSize)windowSize;
 
 
 + (ASTraitCollection *)traitCollectionWithDisplayScale:(CGFloat)displayScale
                                     userInterfaceIdiom:(UIUserInterfaceIdiom)userInterfaceIdiom
                                    horizontalSizeClass:(UIUserInterfaceSizeClass)horizontalSizeClass
                                      verticalSizeClass:(UIUserInterfaceSizeClass)verticalSizeClass
                                   forceTouchCapability:(UIForceTouchCapability)forceTouchCapability
-                                traitCollectionContext:(id)traitCollectionContext;
+                                   containerSize:(CGSize)windowSize;
 
 
 - (ASEnvironmentTraitCollection)environmentTraitCollection;

diff --git a/AsyncDisplayKit/Details/ASTraitCollection.m b/AsyncDisplayKit/Details/ASTraitCollection.m
@@ -21,7 +21,7 @@ - (instancetype)initWithDisplayScale:(CGFloat)displayScale
                  horizontalSizeClass:(UIUserInterfaceSizeClass)horizontalSizeClass
                    verticalSizeClass:(UIUserInterfaceSizeClass)verticalSizeClass
                 forceTouchCapability:(UIForceTouchCapability)forceTouchCapability
-              traitCollectionContext:(id)traitCollectionContext
+                 containerSize:(CGSize)windowSize
 {
     self = [super init];
     if (self) {
@@ -30,7 +30,7 @@ - (instancetype)initWithDisplayScale:(CGFloat)displayScale
       _horizontalSizeClass = horizontalSizeClass;
       _verticalSizeClass = verticalSizeClass;
       _forceTouchCapability = forceTouchCapability;
-      _traitCollectionContext = traitCollectionContext;
+      _containerSize = windowSize;
     }
     return self;
 }
@@ -40,29 +40,29 @@ + (ASTraitCollection *)traitCollectionWithDisplayScale:(CGFloat)displayScale
                                    horizontalSizeClass:(UIUserInterfaceSizeClass)horizontalSizeClass
                                      verticalSizeClass:(UIUserInterfaceSizeClass)verticalSizeClass
                                   forceTouchCapability:(UIForceTouchCapability)forceTouchCapability
-                                traitCollectionContext:(id)traitCollectionContext
+                                   containerSize:(CGSize)windowSize
 {
   return [[[self class] alloc] initWithDisplayScale:displayScale
                                  userInterfaceIdiom:userInterfaceIdiom
                                 horizontalSizeClass:horizontalSizeClass
                                   verticalSizeClass:verticalSizeClass
                                forceTouchCapability:forceTouchCapability
-                             traitCollectionContext:traitCollectionContext];
+                             containerSize:windowSize];
 }
 
 + (ASTraitCollection *)traitCollectionWithASEnvironmentTraitCollection:(ASEnvironmentTraitCollection)traits
 {
-  return [[[self class] alloc] initWithDisplayScale:traits.displayScale
-                                 userInterfaceIdiom:traits.userInterfaceIdiom
-                                horizontalSizeClass:traits.horizontalSizeClass
-                                  verticalSizeClass:traits.verticalSizeClass
-                               forceTouchCapability:traits.forceTouchCapability
-                             traitCollectionContext:traits.displayContext];
+    return [[[self class] alloc] initWithDisplayScale:traits.displayScale
+                                   userInterfaceIdiom:traits.userInterfaceIdiom
+                                  horizontalSizeClass:traits.horizontalSizeClass
+                                    verticalSizeClass:traits.verticalSizeClass
+                                 forceTouchCapability:traits.forceTouchCapability
+                                        containerSize:traits.containerSize];
 
 }
 
 + (ASTraitCollection *)traitCollectionWithUITraitCollection:(UITraitCollection *)traitCollection
-                                     traitCollectionContext:(id)traitCollectionContext
+                                        containerSize:(CGSize)windowSize
 {
   ASTraitCollection *asyncTraitCollection = nil;
   if (AS_AT_LEAST_IOS9) {
@@ -71,15 +71,15 @@ + (ASTraitCollection *)traitCollectionWithUITraitCollection:(UITraitCollection *
                                                   horizontalSizeClass:traitCollection.horizontalSizeClass
                                                     verticalSizeClass:traitCollection.verticalSizeClass
                                                  forceTouchCapability:traitCollection.forceTouchCapability
-                                               traitCollectionContext:traitCollectionContext];
+                                                  containerSize:windowSize];
   }
   else if (AS_AT_LEAST_IOS8) {
     asyncTraitCollection = [[[self class] alloc] initWithDisplayScale:traitCollection.displayScale
                                                    userInterfaceIdiom:traitCollection.userInterfaceIdiom
                                                   horizontalSizeClass:traitCollection.horizontalSizeClass
                                                     verticalSizeClass:traitCollection.verticalSizeClass
                                                  forceTouchCapability:0
-                                               traitCollectionContext:traitCollectionContext];
+                                                  containerSize:windowSize];
   } else {
     asyncTraitCollection = [[[self class] alloc] init];
   }
@@ -95,7 +95,7 @@ - (ASEnvironmentTraitCollection)environmentTraitCollection
     .userInterfaceIdiom = self.userInterfaceIdiom,
     .verticalSizeClass = self.verticalSizeClass,
     .forceTouchCapability = self.forceTouchCapability,
-    .displayContext = self.traitCollectionContext,
+    .containerSize = self.containerSize,
   };
 }
 
@@ -105,7 +105,7 @@ - (BOOL)isEqualToTraitCollection:(ASTraitCollection *)traitCollection
   self.horizontalSizeClass == traitCollection.horizontalSizeClass &&
   self.verticalSizeClass == traitCollection.verticalSizeClass &&
   self.userInterfaceIdiom == traitCollection.userInterfaceIdiom &&
-  self.traitCollectionContext == traitCollection.traitCollectionContext &&
+  CGSizeEqualToSize(self.containerSize, traitCollection.containerSize) &&
   self.forceTouchCapability == traitCollection.forceTouchCapability;
 }
 

diff --git a/AsyncDisplayKit/Private/ASEnvironmentInternal.mm b/AsyncDisplayKit/Private/ASEnvironmentInternal.mm
@@ -207,7 +207,7 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState childEnvi
     childTraitCollection.userInterfaceIdiom = parentTraitCollection.userInterfaceIdiom;
     childTraitCollection.forceTouchCapability = parentTraitCollection.forceTouchCapability;
     childTraitCollection.displayScale = parentTraitCollection.displayScale;
-    childTraitCollection.displayContext = parentTraitCollection.displayContext;
+    childTraitCollection.containerSize = parentTraitCollection.containerSize;
     childEnvironmentState.environmentTraitCollection = childTraitCollection;
 
   }