Exposes ASCollectionView's ability to determine scroll direction. Scroll direction detection can now support 2-axis collection view layouts. ASCollectionView can now determine scrollable axes.

AsyncDisplayKit.xcodeproj/project.pbxproj

@@ -142,6 +142,9 @@
 		05F20AA41A15733C00DCA68A /* ASImageProtocols.h in Headers */ = {isa = PBXBuildFile; fileRef = 05F20AA31A15733C00DCA68A /* ASImageProtocols.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		1950C4491A3BB5C1005C8279 /* ASEqualityHelpers.h in Headers */ = {isa = PBXBuildFile; fileRef = 1950C4481A3BB5C1005C8279 /* ASEqualityHelpers.h */; };
 		204C979E1B362CB3002B1083 /* Default-568h@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 204C979D1B362CB3002B1083 /* Default-568h@2x.png */; };
+		205F0E0F1B371875007741D0 /* UICollectionViewLayout+ASConvenience.h in Headers */ = {isa = PBXBuildFile; fileRef = 205F0E0D1B371875007741D0 /* UICollectionViewLayout+ASConvenience.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		205F0E101B371875007741D0 /* UICollectionViewLayout+ASConvenience.m in Sources */ = {isa = PBXBuildFile; fileRef = 205F0E0E1B371875007741D0 /* UICollectionViewLayout+ASConvenience.m */; };
+		205F0E121B371BD7007741D0 /* ASScrollDirection.m in Sources */ = {isa = PBXBuildFile; fileRef = 205F0E111B371BD7007741D0 /* ASScrollDirection.m */; };
 		242995D31B29743C00090100 /* ASBasicImageDownloaderTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 242995D21B29743C00090100 /* ASBasicImageDownloaderTests.m */; };
 		2911485C1A77147A005D0878 /* ASControlNodeTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 2911485B1A77147A005D0878 /* ASControlNodeTests.m */; };
 		291B63FB1AA53A7A000A71B3 /* ASScrollDirection.h in Headers */ = {isa = PBXBuildFile; fileRef = 296A0A311A951715005ACEAA /* ASScrollDirection.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -318,7 +321,10 @@
 		05EA6FE61AC0966E00E35788 /* ASSnapshotTestCase.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASSnapshotTestCase.mm; sourceTree = "<group>"; };
 		05F20AA31A15733C00DCA68A /* ASImageProtocols.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASImageProtocols.h; sourceTree = "<group>"; };
 		1950C4481A3BB5C1005C8279 /* ASEqualityHelpers.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASEqualityHelpers.h; sourceTree = "<group>"; };
-		204C979D1B362CB3002B1083 /* Default-568h@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "Default-568h@2x.png"; sourceTree = "<group>"; };
+		204C979D1B362CB3002B1083 /* Default-568h@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; name = "Default-568h@2x.png"; path = "../Default-568h@2x.png"; sourceTree = "<group>"; };
+		205F0E0D1B371875007741D0 /* UICollectionViewLayout+ASConvenience.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "UICollectionViewLayout+ASConvenience.h"; sourceTree = "<group>"; };
+		205F0E0E1B371875007741D0 /* UICollectionViewLayout+ASConvenience.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "UICollectionViewLayout+ASConvenience.m"; sourceTree = "<group>"; };
+		205F0E111B371BD7007741D0 /* ASScrollDirection.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASScrollDirection.m; sourceTree = "<group>"; };
 		242995D21B29743C00090100 /* ASBasicImageDownloaderTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASBasicImageDownloaderTests.m; sourceTree = "<group>"; };
 		2911485B1A77147A005D0878 /* ASControlNodeTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASControlNodeTests.m; sourceTree = "<group>"; };
 		292C59991A956527007E5DD6 /* ASLayoutRangeType.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASLayoutRangeType.h; sourceTree = "<group>"; };
@@ -392,6 +398,7 @@
 		057D02C01AC0A66700C7AC3C /* AsyncDisplayKitTestHost */ = {
 			isa = PBXGroup;
 			children = (
+				204C979D1B362CB3002B1083 /* Default-568h@2x.png */,
 				057D02C51AC0A66700C7AC3C /* AppDelegate.h */,
 				057D02C61AC0A66700C7AC3C /* AppDelegate.m */,
 				057D02C11AC0A66700C7AC3C /* Supporting Files */,
@@ -412,7 +419,6 @@
 		058D09A3195D04C000B7D73C = {
 			isa = PBXGroup;
 			children = (
-				204C979D1B362CB3002B1083 /* Default-568h@2x.png */,
 				058D09B1195D04C000B7D73C /* AsyncDisplayKit */,
 				058D09C5195D04C000B7D73C /* AsyncDisplayKitTests */,
 				058D09AE195D04C000B7D73C /* Frameworks */,
@@ -565,6 +571,7 @@
 				292C599D1A956527007E5DD6 /* ASRangeHandlerRender.h */,
 				292C599E1A956527007E5DD6 /* ASRangeHandlerRender.mm */,
 				296A0A311A951715005ACEAA /* ASScrollDirection.h */,
+				205F0E111B371BD7007741D0 /* ASScrollDirection.m */,
 				058D09EA195D050800B7D73C /* ASTextNodeCoreTextAdditions.h */,
 				058D09EB195D050800B7D73C /* ASTextNodeCoreTextAdditions.m */,
 				058D09EC195D050800B7D73C /* ASTextNodeRenderer.h */,
@@ -580,6 +587,8 @@
 				058D09F5195D050800B7D73C /* NSMutableAttributedString+TextKitAdditions.h */,
 				058D09F6195D050800B7D73C /* NSMutableAttributedString+TextKitAdditions.m */,
 				058D09F7195D050800B7D73C /* Transactions */,
+				205F0E0D1B371875007741D0 /* UICollectionViewLayout+ASConvenience.h */,
+				205F0E0E1B371875007741D0 /* UICollectionViewLayout+ASConvenience.m */,
 				058D09FF195D050800B7D73C /* UIView+ASConvenience.h */,
 				058D0A00195D050800B7D73C /* UIView+ASConvenience.m */,
 			);
@@ -704,6 +713,7 @@
 				058D0A66195D05DC00B7D73C /* NSMutableAttributedString+TextKitAdditions.h in Headers */,
 				058D0A67195D05DC00B7D73C /* NSMutableAttributedString+TextKitAdditions.m in Headers */,
 				058D0A68195D05EC00B7D73C /* _ASAsyncTransaction.h in Headers */,
+				205F0E0F1B371875007741D0 /* UICollectionViewLayout+ASConvenience.h in Headers */,
 				058D0A69195D05EC00B7D73C /* _ASAsyncTransaction.m in Headers */,
 				058D0A6A195D05EC00B7D73C /* _ASAsyncTransactionContainer+Private.h in Headers */,
 				058D0A6B195D05EC00B7D73C /* _ASAsyncTransactionContainer.h in Headers */,
@@ -920,6 +930,7 @@
 				058D0A15195D050800B7D73C /* ASDisplayNodeExtras.mm in Sources */,
 				058D0A1F195D050800B7D73C /* ASTextNodeTextKitHelpers.mm in Sources */,
 				055F1A3519ABD3E3004DAFF1 /* ASTableView.mm in Sources */,
+				205F0E121B371BD7007741D0 /* ASScrollDirection.m in Sources */,
 				464052261A3F83C40061C0BA /* ASMultidimensionalArrayUtils.mm in Sources */,
 				055B9FA91A1C154B00035D6D /* ASNetworkImageNode.mm in Sources */,
 				058D0A1D195D050800B7D73C /* ASTextNodeRenderer.mm in Sources */,
@@ -943,6 +954,7 @@
 				058D0A1C195D050800B7D73C /* ASTextNodeCoreTextAdditions.m in Sources */,
 				058D0A13195D050800B7D73C /* ASControlNode.m in Sources */,
 				058D0A19195D050800B7D73C /* _ASDisplayView.mm in Sources */,
+				205F0E101B371875007741D0 /* UICollectionViewLayout+ASConvenience.m in Sources */,
 				05A6D05B19D0EB64002DD95E /* ASDealloc2MainObject.m in Sources */,
 				058D0A17195D050800B7D73C /* ASTextNode.mm in Sources */,
 				058D0A27195D050800B7D73C /* _ASPendingState.m in Sources */,

AsyncDisplayKit/ASCollectionView.h

@@ -131,6 +131,20 @@
  */
 - (CGSize)calculatedSizeForNodeAtIndexPath:(NSIndexPath *)indexPath;
 
+/**
+ * Determines collection view's current scroll direction. Supports 2-axis collection views.
+ *
+ * @returns a bitmask of ASScrollDirection values.
+ */
+- (ASScrollDirection)scrollDirection;
+
+/**
+ * Determines collection view's scrollable directions.
+ *
+ * @returns a bitmask of ASScrollDirection values.
+ */
+- (ASScrollDirection)scrollableDirections;
+
 @end
 
 

AsyncDisplayKit/ASCollectionView.mm

@@ -14,6 +14,7 @@
 #import "ASDataController.h"
 #import "ASDisplayNodeInternal.h"
 #import "ASBatchFetching.h"
+#import "UICollectionViewLayout+ASConvenience.h"
 
 const static NSUInteger kASCollectionViewAnimationNone = UITableViewRowAnimationNone;
 
@@ -141,7 +142,7 @@ static BOOL _isInterceptedSelector(SEL sel)
   // https://github.com/facebook/AsyncDisplayKit/issues/385
   asyncDataFetchingEnabled = NO;
 
-  ASDisplayNodeAssert([layout isKindOfClass:UICollectionViewFlowLayout.class], @"only flow layouts are currently supported");
+  ASDisplayNodeAssert([layout asdk_isFlowLayout], @"only flow layouts are currently supported");
 
   ASFlowLayoutDirection direction = (((UICollectionViewFlowLayout *)layout).scrollDirection == UICollectionViewScrollDirectionHorizontal) ? ASFlowLayoutDirectionHorizontal : ASFlowLayoutDirectionVertical;
   _layoutController = [[ASFlowLayoutController alloc] initWithScrollOption:direction];
@@ -369,24 +370,57 @@ static BOOL _isInterceptedSelector(SEL sel)
 - (ASScrollDirection)scrollDirection
 {
   CGPoint scrollVelocity = [self.panGestureRecognizer velocityInView:self.superview];
+  return [self scrollDirectionForVelocity:scrollVelocity];
+}
+  
+- (ASScrollDirection)scrollDirectionForVelocity:(CGPoint)scrollVelocity
+{
   ASScrollDirection direction = ASScrollDirectionNone;
-  if (_layoutController.layoutDirection == ASFlowLayoutDirectionHorizontal) {
+  ASScrollDirection scrollableDirections = [self scrollableDirections];
+  
+  if (ASScrollDirectionContainsHorizontalDirection(scrollableDirections)) { // Can scroll horizontally.
     if (scrollVelocity.x > 0) {
-      direction = ASScrollDirectionRight;
+      direction |= ASScrollDirectionRight;
-    } else if (scrollVelocity.x < 0) {
+    } else {
-      direction = ASScrollDirectionLeft;
+      direction |= ASScrollDirectionLeft;
     }
-  } else {
+  }
+  if (ASScrollDirectionContainsVerticalDirection(scrollableDirections)) { // Can scroll vertically.
     if (scrollVelocity.y > 0) {
-      direction = ASScrollDirectionDown;
+      direction |= ASScrollDirectionDown;
     } else {
-      direction = ASScrollDirectionUp;
+      direction |= ASScrollDirectionUp;
     }
   }
 
   return direction;
 }
 
+- (ASScrollDirection)scrollableDirections
+{
+  if ([self.collectionViewLayout asdk_isFlowLayout]) {
+    return [self flowLayoutScrollableDirections:(UICollectionViewFlowLayout *)self.collectionViewLayout];
+  } else {
+    return [self nonFlowLayoutScrollableDirections];
+  }
+}
+
+- (ASScrollDirection)flowLayoutScrollableDirections:(UICollectionViewFlowLayout *)flowLayout {
+  return (flowLayout.scrollDirection == UICollectionViewScrollDirectionHorizontal) ? ASScrollDirectionHorizontalDirections : ASScrollDirectionVerticalDirections;
+}
+
+- (ASScrollDirection)nonFlowLayoutScrollableDirections
+{
+  ASScrollDirection scrollableDirection = ASScrollDirectionNone;
+  if (self.contentSize.width > self.bounds.size.width) { // Can scroll horizontally.
+    scrollableDirection |= ASScrollDirectionHorizontalDirections;
+  }
+  if (self.contentSize.height > self.bounds.size.height) { // Can scroll vertically.
+    scrollableDirection |= ASScrollDirectionVerticalDirections;
+  }
+  return scrollableDirection;
+}
+
 - (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath
 {
   [_rangeController visibleNodeIndexPathsDidChangeWithScrollDirection:self.scrollDirection];

AsyncDisplayKit/Details/ASScrollDirection.h

@@ -8,6 +8,8 @@
 
 #import <Foundation/Foundation.h>
 
+#import "ASBaseDefines.h"
+
 typedef NS_OPTIONS(NSInteger, ASScrollDirection) {
   ASScrollDirectionNone  = 0,
   ASScrollDirectionRight = 1 << 0,
@@ -15,3 +17,13 @@ typedef NS_OPTIONS(NSInteger, ASScrollDirection) {
   ASScrollDirectionUp    = 1 << 2,
   ASScrollDirectionDown  = 1 << 3
 };
+
+extern const ASScrollDirection ASScrollDirectionHorizontalDirections;
+extern const ASScrollDirection ASScrollDirectionVerticalDirections;
+
+ASDISPLAYNODE_EXTERN_C_BEGIN
+
+BOOL ASScrollDirectionContainsVerticalDirection(ASScrollDirection scrollDirection);
+BOOL ASScrollDirectionContainsHorizontalDirection(ASScrollDirection scrollDirection);
+
+ASDISPLAYNODE_EXTERN_C_END

AsyncDisplayKit/Details/ASScrollDirection.m

@@ -0,0 +1,20 @@
+/* Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "ASScrollDirection.h"
+
+const ASScrollDirection ASScrollDirectionHorizontalDirections = ASScrollDirectionLeft | ASScrollDirectionRight;
+const ASScrollDirection ASScrollDirectionVerticalDirections = ASScrollDirectionUp | ASScrollDirectionDown;
+
+BOOL ASScrollDirectionContainsVerticalDirection(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionVerticalDirections) != 0;
+}
+
+BOOL ASScrollDirectionContainsHorizontalDirection(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionHorizontalDirections) != 0;
+}

AsyncDisplayKit/Details/UICollectionViewLayout+ASConvenience.h

@@ -0,0 +1,15 @@
+/* Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <UIKit/UIKit.h>
+
+@interface UICollectionViewLayout (ASConvenience)
+
+- (BOOL)asdk_isFlowLayout;
+
+@end

AsyncDisplayKit/Details/UICollectionViewLayout+ASConvenience.m

@@ -0,0 +1,17 @@
+/* Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "UICollectionViewLayout+ASConvenience.h"
+
+@implementation UICollectionViewLayout (ASConvenience)
+
+- (BOOL)asdk_isFlowLayout {
+  return [self isKindOfClass:UICollectionViewFlowLayout.class];
+}
+
+@end