[ASEnvironment - Layout] Fixes to upward propagation of ASLayoutable properties.

AsyncDisplayKit/ASDisplayNode.mm

@@ -1702,10 +1702,6 @@ static NSInteger incrementIfFound(NSInteger i) {
       [self exitHierarchyState:stateToEnterOrExit];
     }
   }
-    
-  if ([newSupernode supportsUpwardPropagation]) {
-    ASEnvironmentStatePropagateUp(newSupernode, _environmentState.layoutOptionsState);
-  }
 }
 
 // Track that a node will be displayed as part of the current node hierarchy.
@@ -1860,7 +1856,7 @@ void recursivelyTriggerDisplayForLayer(CALayer *layer, BOOL shouldBlock)
   ASDN::MutexLocker l(_propertyLock);
   if (_methodOverrides & ASDisplayNodeMethodOverrideLayoutSpecThatFits) {
     ASLayoutSpec *layoutSpec = [self layoutSpecThatFits:constrainedSize];
-    layoutSpec.parent = self;
+    layoutSpec.parent = self; // This causes upward propogation of any non-default layoutable values.
     layoutSpec.isMutable = NO;
     ASLayout *layout = [layoutSpec measureWithSizeRange:constrainedSize];
     // Make sure layoutableObject of the root layout is `self`, so that the flattened layout will be structurally correct.

AsyncDisplayKit/Layout/ASLayoutSpec.mm

@@ -81,8 +81,8 @@ static NSString * const kDefaultChildrenKey = @"kDefaultChildrenKey";
 
     id<ASLayoutable> finalLayoutable = [child finalLayoutable];
     if (finalLayoutable != child) {
-      // Layout options state of child needs to be copied to final layoutable
-      finalLayoutable.environmentState.layoutOptionsState = child.environmentState.layoutOptionsState;
+      // Layout options state of child needs to be copied to final layoutable, but don't override customized values.
+      ASEnvironmentStatePropagateUp(finalLayoutable, child.environmentState.layoutOptionsState);
       return finalLayoutable;
     }
   }
@@ -99,10 +99,11 @@ static NSString * const kDefaultChildrenKey = @"kDefaultChildrenKey";
 
 - (void)setParent:(id<ASLayoutable>)parent
 {
+  // FIXME: Locking should be evaluated here.  _parent is not widely used yet, though.
   _parent = parent;
   
   if ([parent supportsUpwardPropagation]) {
-    ASEnvironmentStatePropagateUp(parent, _environmentState.layoutOptionsState);
+    ASEnvironmentStatePropagateUp(parent, self.environmentState.layoutOptionsState);
   }
 }
 
@@ -115,12 +116,11 @@ static NSString * const kDefaultChildrenKey = @"kDefaultChildrenKey";
 {
   ASDisplayNodeAssert(self.isMutable, @"Cannot set properties when layout spec is not mutable");
   id<ASLayoutable> finalLayoutable = [self layoutableToAddFromLayoutable:child];
-  BOOL needsToPropagateLayoutOptionsState = (child != finalLayoutable);
   self.layoutChildren[identifier] = finalLayoutable;
-  if (needsToPropagateLayoutOptionsState) {
-    // We only need to propagate up layout options in setChild: as up propagation is currently only supported for
-    // layout specification has with one child
-    [self propagateUpLayoutOptionsState];
+  if ([finalLayoutable isKindOfClass:[ASLayoutSpec class]]) {
+    [(ASLayoutSpec *)finalLayoutable setParent:self]; // This will trigger upward propogation if needed.
+  } else if ([self supportsUpwardPropagation]) {
+    ASEnvironmentStatePropagateUp(self, finalLayoutable.environmentState.layoutOptionsState); // Probably an ASDisplayNode
   }
 }
 

AsyncDisplayKit/Private/ASEnvironmentInternal.mm

@@ -115,33 +115,33 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environme
     
     // For every field check if the parent value is equal to the default than propegate up the child value to
     // the parent
-    if (parentState.spacingBefore != defaultState.spacingBefore) {
+    if (parentState.spacingBefore == defaultState.spacingBefore) {
       parentState.spacingBefore = state.spacingBefore;
     }
-    if (parentState.spacingAfter != defaultState.spacingAfter) {
+    if (parentState.spacingAfter == defaultState.spacingAfter) {
       parentState.spacingAfter = state.spacingAfter;
     }
-    if (parentState.alignSelf != defaultState.alignSelf) {
-      parentState.alignSelf = defaultState.alignSelf;
+    if (parentState.alignSelf == defaultState.alignSelf) {
+      parentState.alignSelf = state.alignSelf;
     }
-    if (parentState.flexGrow != defaultState.flexGrow) {
-      parentState.flexGrow = defaultState.flexGrow;
+    if (parentState.flexGrow == defaultState.flexGrow) {
+      parentState.flexGrow = state.flexGrow;
     }
-    if (!ASRelativeDimensionEqualToRelativeDimension(parentState.flexBasis, defaultState.flexBasis)) {
-      parentState.flexBasis = defaultState.flexBasis;
+    if (ASRelativeDimensionEqualToRelativeDimension(parentState.flexBasis, defaultState.flexBasis)) {
+      parentState.flexBasis = state.flexBasis;
     }
-    if (parentState.alignSelf != defaultState.alignSelf) {
-      parentState.alignSelf = defaultState.alignSelf;
+    if (parentState.alignSelf == defaultState.alignSelf) {
+      parentState.alignSelf = state.alignSelf;
     }
-    if (parentState.ascender != defaultState.ascender) {
-      parentState.ascender = defaultState.ascender;
+    if (parentState.ascender == defaultState.ascender) {
+      parentState.ascender = state.ascender;
     }
     
-    if (!ASRelativeSizeRangeEqualToRelativeSizeRange(parentState.sizeRange, defaultState.sizeRange)) {
-      parentState.sizeRange = defaultState.sizeRange;
+    if (ASRelativeSizeRangeEqualToRelativeSizeRange(parentState.sizeRange, defaultState.sizeRange)) {
+      parentState.sizeRange = state.sizeRange;
     }
     if (CGPointEqualToPoint(parentState.layoutPosition, defaultState.layoutPosition)) {
-      parentState.layoutPosition = defaultState.layoutPosition;
+      parentState.layoutPosition = state.layoutPosition;
     }
     
     environmentState.layoutOptionsState = parentState;

examples/SocialAppLayout/Sample/AppDelegate.h

@@ -15,6 +15,4 @@
 
 @property (strong, nonatomic) UIWindow *window;
 
-
 @end
-

examples/SocialAppLayout/Sample/AppDelegate.m

@@ -10,23 +10,17 @@
  */
 
 #import "AppDelegate.h"
-
 #import "ViewController.h"
 
-@interface AppDelegate ()
-
-@end
-
 @implementation AppDelegate
 
-
-- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
+{
     self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
     self.window.backgroundColor = [UIColor whiteColor];
     self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:[[ViewController alloc] init]];
     [self.window makeKeyAndVisible];
     return YES;
-
 }
 
 @end

examples/SocialAppLayout/Sample/CommentsNode.m

@@ -20,8 +20,8 @@
 
 @implementation CommentsNode
 
-- (instancetype)initWithCommentsCount:(NSInteger)comentsCount {
-    
+- (instancetype)initWithCommentsCount:(NSInteger)comentsCount
+{
     self = [super init];
     if (self) {
         _commentsCount = comentsCount;
@@ -44,8 +44,8 @@
     
 }
 
-- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize {
-    
+- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
+{
     ASStackLayoutSpec *mainStack =  [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal spacing:6.0 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsCenter children:@[self.iconNode, self.countNode]];
     
     // set sizeRange to make width fixed to 60
@@ -55,5 +55,4 @@
     return [ASStaticLayoutSpec staticLayoutSpecWithChildren:@[mainStack]];
 }
 
-
 @end

examples/SocialAppLayout/Sample/LikesNode.m

@@ -21,8 +21,8 @@
 
 @implementation LikesNode
 
-- (instancetype)initWithLikesCount:(NSInteger)likesCount {
-    
+- (instancetype)initWithLikesCount:(NSInteger)likesCount
+{
     self = [super init];
     if (self) {
         _likesCount = likesCount;
@@ -49,7 +49,7 @@
     
 }
 
-+ (BOOL) getYesOrNo
++ (BOOL)getYesOrNo
 {
     int tmp = (arc4random() % 30)+1;
     if (tmp % 5 == 0) {
@@ -58,8 +58,8 @@
     return NO;
 }
 
-- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize {
-    
+- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
+{
     ASStackLayoutSpec *mainStack = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal spacing:6.0 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsCenter children:@[_iconNode, _countNode]];
     
     // set sizeRange to make width fixed to 60
@@ -67,7 +67,6 @@
     ASRelativeSize max = ASRelativeSizeMake(ASRelativeDimensionMakeWithPoints(60.0), ASRelativeDimensionMakeWithPoints(40.0));
     mainStack.sizeRange = ASRelativeSizeRangeMake(min, max);
     return [ASStaticLayoutSpec staticLayoutSpecWithChildren:@[mainStack]];
-    
 }
 
 @end

examples/SocialAppLayout/Sample/Post.m

@@ -12,5 +12,4 @@
 #import "Post.h"
 
 @implementation Post
-
 @end

examples/SocialAppLayout/Sample/PostNode.m

@@ -34,8 +34,8 @@
 
 @implementation PostNode
 
-- (instancetype)initWithPost:(Post *)post {
-    
+- (instancetype)initWithPost:(Post *)post
+{
     self = [super init];
     if (self) {
         _post = post;
@@ -181,14 +181,19 @@
     [super didLoad];
 }
 
-- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize {
-    
+- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
+{
     // Flexible spacer between username and time
     ASLayoutSpec *spacer = [[ASLayoutSpec alloc] init];
     spacer.flexGrow = YES;
-    
+  
+    // NOTE: This inset is not actually required by the layout, but is an example of the upward propogation of layoutable
+    // properties.  Specifically, .flexGrow from the child is transferred to the inset spec so they can expand together.
+    // Without this capability, it would be required to set insetSpacer.flexGrow = YES;
+    ASInsetLayoutSpec *insetSpacer = [ASInsetLayoutSpec insetLayoutSpecWithInsets:UIEdgeInsetsMake(0, 0, 0, 0) child:spacer];
+  
     // Horizontal stack for name, username, via icon and time
-    NSMutableArray *layoutSpecChildren = [@[_nameNode, _usernameNode, spacer] mutableCopy];
+    NSMutableArray *layoutSpecChildren = [@[_nameNode, _usernameNode, insetSpacer] mutableCopy];
     if (_post.via != 0) {
         [layoutSpecChildren addObject:_viaNode];
     }

examples/SocialAppLayout/Sample/TextStyles.m

@@ -54,16 +54,16 @@
     };
 }
 
-+ (NSDictionary *)cellControlStyle {
-    
++ (NSDictionary *)cellControlStyle
+{
     return @{
         NSFontAttributeName : [UIFont systemFontOfSize:13.0],
         NSForegroundColorAttributeName: [UIColor lightGrayColor]
     };
 }
 
-+ (NSDictionary *)cellControlColoredStyle {
-    
++ (NSDictionary *)cellControlColoredStyle
+{
     return @{
         NSFontAttributeName : [UIFont systemFontOfSize:13.0],
         NSForegroundColorAttributeName: [UIColor colorWithRed:59.0/255.0 green:89.0/255.0 blue:152.0/255.0 alpha:1.0]

examples/SocialAppLayout/Sample/ViewController.h

@@ -12,7 +12,4 @@
 #import <UIKit/UIKit.h>
 
 @interface ViewController : UIViewController
-
-
 @end
-

examples/SocialAppLayout/Sample/ViewController.m

@@ -45,8 +45,8 @@
     _tableView.asyncDelegate = nil;
 }
 
-- (void)viewDidLoad {
-    
+- (void)viewDidLoad
+{
     [super viewDidLoad];
     
     self.tableView = [[ASTableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain asyncDataFetching:YES];
@@ -57,8 +57,8 @@
     [self.view addSubview:self.tableView];
 }
 
-- (void)createSocialAppDataSource {
-    
+- (void)createSocialAppDataSource
+{
     _socialAppDataSource = [[NSMutableArray alloc] init];
     
     Post *newPost = [[Post alloc] init];