From 27cc2bec82fa7d7779e87a5756c4bbf798241d65 Mon Sep 17 00:00:00 2001
From: Michael Schneider <mischneider1@gmail.com>
Date: Tue, 5 Apr 2016 14:21:55 -0700
Subject: [PATCH] Add merging ASEnvironmentStateExtensions on upward
 propegation

---
 .../Private/ASEnvironmentInternal.h           |  2 +
 .../Private/ASEnvironmentInternal.mm          | 73 +++++++++++++------
 2 files changed, 51 insertions(+), 24 deletions(-)

diff --git a/AsyncDisplayKit/Private/ASEnvironmentInternal.h b/AsyncDisplayKit/Private/ASEnvironmentInternal.h
index 9cf9a11e55..e69bed23a0 100644
--- a/AsyncDisplayKit/Private/ASEnvironmentInternal.h
+++ b/AsyncDisplayKit/Private/ASEnvironmentInternal.h
@@ -35,6 +35,8 @@ void ASEnvironmentPerformBlockOnObjectAndParents(id<ASEnvironment> object, void(
 
 #pragma mark - Merging
 
+static const struct ASEnvironmentStateExtensions ASEnvironmentDefaultStateExtensions = {};
+
 static const struct ASEnvironmentLayoutOptionsState ASEnvironmentDefaultLayoutOptionsState = {};
 ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentLayoutOptionsState state, ASEnvironmentStatePropagation propagation);
 
diff --git a/AsyncDisplayKit/Private/ASEnvironmentInternal.mm b/AsyncDisplayKit/Private/ASEnvironmentInternal.mm
index b49fbd0e48..909787a560 100644
--- a/AsyncDisplayKit/Private/ASEnvironmentInternal.mm
+++ b/AsyncDisplayKit/Private/ASEnvironmentInternal.mm
@@ -96,13 +96,13 @@ UIEdgeInsets _ASEnvironmentLayoutOptionsExtensionGetEdgeInsetsAtIndex(id<ASEnvir
 
 #pragma mark - Merging functions for states
 
-ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentHierarchyState state, ASEnvironmentStatePropagation propagation) {
+ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentHierarchyState hierarchyState, ASEnvironmentStatePropagation propagation) {
     // Merge object and hierarchy state
   LOG(@"Merge object and state: %@ - ASEnvironmentHierarchyState", object);
   return environmentState;
 }
 
-ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentLayoutOptionsState state, ASEnvironmentStatePropagation propagation) {
+ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environmentState, ASEnvironmentLayoutOptionsState layoutOptionsState, ASEnvironmentStatePropagation propagation) {
   // Merge object and layout options state
   LOG(@"Merge object and state: %@ - ASEnvironmentLayoutOptionsState", object);
   
@@ -111,40 +111,65 @@ ASEnvironmentState ASEnvironmentMergeObjectAndState(ASEnvironmentState environme
 
    // Object is the parent and the state is the state of the child
     const ASEnvironmentLayoutOptionsState defaultState = ASEnvironmentDefaultLayoutOptionsState;
-    ASEnvironmentLayoutOptionsState parentState = environmentState.layoutOptionsState;
+    ASEnvironmentLayoutOptionsState parentLayoutOptionsState = environmentState.layoutOptionsState;
     
-    // 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) {
-      parentState.spacingBefore = state.spacingBefore;
+    // For every field check if the parent value is equal to the default and if so propegate up the value of the passed
+    // in layout options state
+    if (parentLayoutOptionsState.spacingBefore == defaultState.spacingBefore) {
+      parentLayoutOptionsState.spacingBefore = layoutOptionsState.spacingBefore;
     }
-    if (parentState.spacingAfter == defaultState.spacingAfter) {
-      parentState.spacingAfter = state.spacingAfter;
+    if (parentLayoutOptionsState.spacingAfter == defaultState.spacingAfter) {
+      parentLayoutOptionsState.spacingAfter = layoutOptionsState.spacingAfter;
     }
-    if (parentState.alignSelf == defaultState.alignSelf) {
-      parentState.alignSelf = state.alignSelf;
+    if (parentLayoutOptionsState.alignSelf == defaultState.alignSelf) {
+      parentLayoutOptionsState.alignSelf = layoutOptionsState.alignSelf;
     }
-    if (parentState.flexGrow == defaultState.flexGrow) {
-      parentState.flexGrow = state.flexGrow;
+    if (parentLayoutOptionsState.flexGrow == defaultState.flexGrow) {
+      parentLayoutOptionsState.flexGrow = layoutOptionsState.flexGrow;
     }
-    if (ASRelativeDimensionEqualToRelativeDimension(parentState.flexBasis, defaultState.flexBasis)) {
-      parentState.flexBasis = state.flexBasis;
+    if (ASRelativeDimensionEqualToRelativeDimension(parentLayoutOptionsState.flexBasis, defaultState.flexBasis)) {
+      parentLayoutOptionsState.flexBasis = layoutOptionsState.flexBasis;
     }
-    if (parentState.alignSelf == defaultState.alignSelf) {
-      parentState.alignSelf = state.alignSelf;
+    if (parentLayoutOptionsState.alignSelf == defaultState.alignSelf) {
+      parentLayoutOptionsState.alignSelf = layoutOptionsState.alignSelf;
     }
-    if (parentState.ascender == defaultState.ascender) {
-      parentState.ascender = state.ascender;
+    if (parentLayoutOptionsState.ascender == defaultState.ascender) {
+      parentLayoutOptionsState.ascender = layoutOptionsState.ascender;
     }
     
-    if (ASRelativeSizeRangeEqualToRelativeSizeRange(parentState.sizeRange, defaultState.sizeRange)) {
-      parentState.sizeRange = state.sizeRange;
+    if (ASRelativeSizeRangeEqualToRelativeSizeRange(parentLayoutOptionsState.sizeRange, defaultState.sizeRange)) {
+      parentLayoutOptionsState.sizeRange = layoutOptionsState.sizeRange;
     }
-    if (CGPointEqualToPoint(parentState.layoutPosition, defaultState.layoutPosition)) {
-      parentState.layoutPosition = state.layoutPosition;
+    if (CGPointEqualToPoint(parentLayoutOptionsState.layoutPosition, defaultState.layoutPosition)) {
+      parentLayoutOptionsState.layoutPosition = layoutOptionsState.layoutPosition;
     }
     
-    environmentState.layoutOptionsState = parentState;
+    // Merge extended values if necessary
+    const ASEnvironmentStateExtensions defaultExtensions = ASEnvironmentDefaultStateExtensions;
+    const ASEnvironmentStateExtensions layoutOptionsStateExtensions = layoutOptionsState._extensions;
+    ASEnvironmentStateExtensions parentLayoutOptionsExtensions = parentLayoutOptionsState._extensions;
+    
+    for (int i = 0; i < kMaxEnvironmentStateBoolExtensions; i++) {
+      if (parentLayoutOptionsExtensions.boolExtensions[i] == defaultExtensions.boolExtensions[i]) {
+        parentLayoutOptionsExtensions.boolExtensions[i] = layoutOptionsStateExtensions.boolExtensions[i];
+      }
+    }
+    
+    for (int i = 0; i < kMaxEnvironmentStateIntegerExtensions; i++) {
+      if (parentLayoutOptionsExtensions.integerExtensions[i] == defaultExtensions.integerExtensions[i]) {
+        parentLayoutOptionsExtensions.integerExtensions[i] = layoutOptionsStateExtensions.integerExtensions[i];
+      }
+    }
+    
+    for (int i = 0; i < kMaxEnvironmentStateEdgeInsetExtensions; i++) {
+      if (UIEdgeInsetsEqualToEdgeInsets(parentLayoutOptionsExtensions.edgeInsetsExtensions[i], defaultExtensions.edgeInsetsExtensions[i])) {
+        parentLayoutOptionsExtensions.edgeInsetsExtensions[i] = layoutOptionsStateExtensions.edgeInsetsExtensions[i];
+      }
+    }
+    parentLayoutOptionsState._extensions = parentLayoutOptionsExtensions;
+    
+    // Update layout options state
+    environmentState.layoutOptionsState = parentLayoutOptionsState;
   }
   
   return environmentState;