Add ASLegacyCollectionLayoutCalculator for backward compatibility

AsyncDisplayKit.xcodeproj/project.pbxproj

@@ -368,6 +368,8 @@
 		DECBD6E81BE56E1900CF4905 /* ASButtonNode.h in Headers */ = {isa = PBXBuildFile; fileRef = DECBD6E51BE56E1900CF4905 /* ASButtonNode.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		DECBD6EA1BE56E1900CF4905 /* ASButtonNode.mm in Sources */ = {isa = PBXBuildFile; fileRef = DECBD6E61BE56E1900CF4905 /* ASButtonNode.mm */; };
 		DEFAD8131CC48914000527C4 /* ASVideoNode.mm in Sources */ = {isa = PBXBuildFile; fileRef = AEEC47E01C20C2DD00EC1693 /* ASVideoNode.mm */; };
+		E52465C01E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.h in Headers */ = {isa = PBXBuildFile; fileRef = E52465BE1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		E52465C11E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.m in Sources */ = {isa = PBXBuildFile; fileRef = E52465BF1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.m */; };
 		E55D86331CA8A14000A0C26F /* ASLayoutElement.mm in Sources */ = {isa = PBXBuildFile; fileRef = E55D86311CA8A14000A0C26F /* ASLayoutElement.mm */; };
 		E5711A2C1C840C81009619D4 /* ASCollectionElement.h in Headers */ = {isa = PBXBuildFile; fileRef = E5711A2A1C840C81009619D4 /* ASCollectionElement.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E5711A301C840C96009619D4 /* ASCollectionElement.mm in Sources */ = {isa = PBXBuildFile; fileRef = E5711A2D1C840C96009619D4 /* ASCollectionElement.mm */; };
@@ -775,6 +777,8 @@
 		DECBD6E61BE56E1900CF4905 /* ASButtonNode.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASButtonNode.mm; sourceTree = "<group>"; };
 		E52405B21C8FEF03004DC8E7 /* ASLayoutTransition.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASLayoutTransition.mm; sourceTree = "<group>"; };
 		E52405B41C8FEF16004DC8E7 /* ASLayoutTransition.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASLayoutTransition.h; sourceTree = "<group>"; };
+		E52465BE1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASLegacyCollectionLayoutCalculator.h; sourceTree = "<group>"; };
+		E52465BF1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASLegacyCollectionLayoutCalculator.m; sourceTree = "<group>"; };
 		E55D86311CA8A14000A0C26F /* ASLayoutElement.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASLayoutElement.mm; sourceTree = "<group>"; };
 		E5711A2A1C840C81009619D4 /* ASCollectionElement.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASCollectionElement.h; sourceTree = "<group>"; };
 		E5711A2D1C840C96009619D4 /* ASCollectionElement.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASCollectionElement.mm; sourceTree = "<group>"; };
@@ -1399,6 +1403,8 @@
 				E5B077F01E6855B100C24B5B /* ASCollectionLayoutSpecCalculator.m */,
 				E5B0780A1E6A01E200C24B5B /* ASCollectionFlowLayoutCalculator.h */,
 				E5B0780B1E6A01E200C24B5B /* ASCollectionFlowLayoutCalculator.m */,
+				E52465BE1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.h */,
+				E52465BF1E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.m */,
 				E5B077E11E6843A600C24B5B /* ASCollectionViewLayout.h */,
 				E5B077F41E68576B00C24B5B /* ASCollectionViewLayout.m */,
 			);
@@ -1422,6 +1428,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				E52465C01E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.h in Headers */,
 				E5B0780C1E6A01E200C24B5B /* ASCollectionFlowLayoutCalculator.h in Headers */,
 				E5B077EE1E68558200C24B5B /* ASCollectionLayoutSpecCalculator.h in Headers */,
 				E5B077EA1E6843A600C24B5B /* ASCollectionLayoutCalculating.h in Headers */,
@@ -1891,6 +1898,7 @@
 				68FC85EC1CE29C7D00EDD713 /* ASVisibilityProtocols.m in Sources */,
 				CC55A7121E52A0F200594372 /* ASResponderChainEnumerator.m in Sources */,
 				68B8A4E41CBDB958007E4543 /* ASWeakProxy.m in Sources */,
+				E52465C11E6DE877003632D0 /* ASLegacyCollectionLayoutCalculator.m in Sources */,
 				9C70F20A1CDBE949007D6C76 /* ASTableNode.mm in Sources */,
 				69CB62AE1CB8165900024920 /* _ASDisplayViewAccessiblity.mm in Sources */,
 				B35061F61B010EFD0018CF92 /* ASCollectionView.mm in Sources */,

Source/ASCollectionView.mm

@@ -17,14 +17,13 @@
 #import <AsyncDisplayKit/ASCollectionInternal.h>
 #import <AsyncDisplayKit/ASCollectionViewLayoutController.h>
 #import <AsyncDisplayKit/ASCollectionViewLayout.h>
-#import <AsyncDisplayKit/ASCollectionLayoutCalculating.h>
-#import <AsyncDisplayKit/ASCollectionFlowLayoutCalculator.h>
 #import <AsyncDisplayKit/ASCollectionViewFlowLayoutInspector.h>
 #import <AsyncDisplayKit/ASDataController.h>
 #import <AsyncDisplayKit/ASDisplayNodeExtras.h>
 #import <AsyncDisplayKit/ASDisplayNode+FrameworkPrivate.h>
 #import <AsyncDisplayKit/ASElementMap.h>
 #import <AsyncDisplayKit/ASInternalHelpers.h>
+#import <AsyncDisplayKit/ASLegacyCollectionLayoutCalculator.h>
 #import <AsyncDisplayKit/UICollectionViewLayout+ASConvenience.h>
 #import <AsyncDisplayKit/ASRangeController.h>
 #import <AsyncDisplayKit/ASCollectionNode.h>
@@ -144,6 +143,8 @@ @interface ASCollectionView () <ASRangeControllerDataSource, ASRangeControllerDe
    */
   NSInteger _batchUpdateCount;
 
+  id<ASCollectionLayoutCalculating> _layoutCalculator;
+
   struct {
     unsigned int scrollViewDidScroll:1;
     unsigned int scrollViewWillBeginDragging:1;
@@ -218,8 +219,9 @@ @interface ASCollectionView () <ASRangeControllerDataSource, ASRangeControllerDe
   } _layoutInspectorFlags;
 
   struct {
-    unsigned int providesLayoutCalculator;
-    unsigned int consumesResultOfLayoutCalculator;
+    unsigned int isASCollectionViewLayout:1;
+    unsigned int providesLayoutCalculator:1;
+    unsigned int consumesResultOfLayoutCalculator:1;
   } _collectionViewLayoutFlags;
 
 }
@@ -256,7 +258,7 @@ - (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionV
   if (!(self = [super initWithFrame:frame collectionViewLayout:layout]))
     return nil;
 
-  [self _configureCollectionViewLayout:layout];
+  [self _configureCollectionViewLayoutFlags:layout];
 
   // Disable UICollectionView prefetching.
   // Experiments done by Instagram show that this option being YES (default)
@@ -545,7 +547,7 @@ - (void)setCollectionViewLayout:(nonnull UICollectionViewLayout *)collectionView
 {
   [super setCollectionViewLayout:collectionViewLayout];
 
-  [self _configureCollectionViewLayout:collectionViewLayout];
+  [self _configureCollectionViewLayoutFlags:collectionViewLayout];
 
   // Trigger recreation of layout inspector with new collection view layout
   if (_layoutInspector != nil) {
@@ -754,8 +756,9 @@ - (NSArray *)visibleNodes
 
 #pragma mark Internal
 
-- (void)_configureCollectionViewLayout:(nonnull UICollectionViewLayout *)layout
+- (void)_configureCollectionViewLayoutFlags:(nonnull UICollectionViewLayout *)layout
 {
+  _collectionViewLayoutFlags.isASCollectionViewLayout = [layout isKindOfClass:[ASCollectionViewLayout class]];
   _collectionViewLayoutFlags.providesLayoutCalculator = [layout conformsToProtocol:@protocol(ASCollectionLayoutCalculatorProviding)];
   _collectionViewLayoutFlags.consumesResultOfLayoutCalculator = [layout conformsToProtocol:@protocol(ASCollectionLayoutCalculatorResultConsuming)];
 }
@@ -1519,14 +1522,30 @@ - (void)_beginBatchFetching
 
 #pragma mark - ASCollectionLayoutCalculatorProviding
 
-- (id<ASCollectionLayoutCalculating>)collectionViewLayoutCalculator
+- (id<ASCollectionLayoutCalculating>)collectionLayoutCalculator
 {
-  return _collectionViewLayoutFlags.providesLayoutCalculator ? [(id<ASCollectionLayoutCalculatorProviding>)self.collectionViewLayout collectionViewLayoutCalculator] : nil;
+  ASDisplayNodeAssertMainThread();
+  // If layout object provides layout calculator, use it. But clear any existing default calculator first.
+  if (_collectionViewLayoutFlags.providesLayoutCalculator) {
+    _layoutCalculator = nil;
+    return [(id<ASCollectionLayoutCalculatorProviding>)self.collectionViewLayout collectionLayoutCalculator];
+  }
+
+  // Layout object doesn't provide a layout calculator. Lazily create a default one.
+  if (_layoutCalculator == nil) {
+    _layoutCalculator = [[ASLegacyCollectionLayoutCalculator alloc] init];
+  }
+  return _layoutCalculator;
 }
 
 - (CGSize)viewportSizeForCollectionLayout
 {
-  return _collectionViewLayoutFlags.providesLayoutCalculator ? [(id<ASCollectionLayoutCalculatorProviding>)self.collectionViewLayout viewportSizeForCollectionLayout] : CGSizeZero;
+  ASDisplayNodeAssertMainThread();
+  if (_collectionViewLayoutFlags.providesLayoutCalculator) {
+    return [(id<ASCollectionLayoutCalculatorProviding>)self.collectionViewLayout viewportSizeForCollectionLayout];
+  } else {
+    return self.bounds.size;
+  }
 }
 
 #pragma mark - ASCollectionLayoutCalculatorResultConsuming
@@ -1705,9 +1724,7 @@ - (ASSizeRange)dataController:(ASDataController *)dataController constrainedSize
     return [self.layoutInspector collectionView:self constrainedSizeForSupplementaryNodeOfKind:kind atIndexPath:indexPath];
   }
 
-  if (_collectionViewLayoutFlags.providesLayoutCalculator == NO) {
-    ASDisplayNodeAssert(NO, @"To support supplementary nodes in ASCollectionView, it must have a layoutInspector for layout inspection. (See ASCollectionViewFlowLayoutInspector for an example.)");
-  }
+  ASDisplayNodeAssert(NO, @"To support supplementary nodes in ASCollectionView, it must have a layoutInspector for layout inspection. (See ASCollectionViewFlowLayoutInspector for an example.)");
   return ASSizeRangeMake(CGSizeZero, CGSizeZero);
 }
 
@@ -2050,7 +2067,9 @@ - (void)layer:(CALayer *)layer didChangeBoundsWithOldValue:(CGRect)oldBounds new
   if (self.collectionViewLayout == nil) {
     return;
   }
-  if (_collectionViewLayoutFlags.providesLayoutCalculator) {
+  if (_collectionViewLayoutFlags.isASCollectionViewLayout) {
+    // ASCollectionViewLayout should be able to handle bounds changes and automatically re-run its calculator.
+    // TODO This is more or less a workaround for the current relayout system which is destined for an overhaul.
     return;
   }
   CGSize lastUsedSize = _lastBoundsSizeUsedForMeasuringNodes;

Source/ASTableView.mm

@@ -24,6 +24,7 @@
 #import <AsyncDisplayKit/ASElementMap.h>
 #import <AsyncDisplayKit/ASInternalHelpers.h>
 #import <AsyncDisplayKit/ASLayout.h>
+#import <AsyncDisplayKit/ASLegacyCollectionLayoutCalculator.h>
 #import <AsyncDisplayKit/ASTableNode.h>
 #import <AsyncDisplayKit/ASRangeController.h>
 #import <AsyncDisplayKit/ASEqualityHelpers.h>
@@ -181,6 +182,8 @@ @interface ASTableView () <ASRangeControllerDataSource, ASRangeControllerDelegat
    */
   NSInteger _batchUpdateCount;
 
+  id<ASCollectionLayoutCalculating> _layoutCalculator;
+
   struct {
     unsigned int scrollViewDidScroll:1;
     unsigned int scrollViewWillBeginDragging:1;
@@ -288,6 +291,8 @@ - (void)configureWithDataControllerClass:(Class)dataControllerClass eventLog:(AS
 
   _proxyDataSource = [[ASTableViewProxy alloc] initWithTarget:nil interceptor:self];
   super.dataSource = (id<UITableViewDataSource>)_proxyDataSource;
+
+  _layoutCalculator = [[ASLegacyCollectionLayoutCalculator alloc] init];
 
   [self registerClass:_ASTableViewCell.class forCellReuseIdentifier:kCellReuseIdentifier];
 }
@@ -1542,7 +1547,19 @@ - (void)rangeController:(ASRangeController *)rangeController didUpdateWithChange
   [changeSet executeCompletionHandlerWithFinished:YES];
 }
 
-#pragma mark - ASDataControllerDelegate
+#pragma mark - ASDataControllerSource
+
+- (id<ASCollectionLayoutCalculating>)collectionLayoutCalculator
+{
+  ASDisplayNodeAssertMainThread();
+  return _layoutCalculator;
+}
+
+- (CGSize)viewportSizeForCollectionLayout
+{
+  ASDisplayNodeAssertMainThread();
+  return CGSizeMake(_nodesConstrainedWidth, self.bounds.size.height);
+}
 
 - (ASCellNodeBlock)dataController:(ASDataController *)dataController nodeBlockAtIndexPath:(NSIndexPath *)indexPath {
   ASCellNodeBlock block = nil;

Source/AsyncDisplayKit.h

@@ -32,15 +32,16 @@
 #import <AsyncDisplayKit/ASTableNode.h>
 #import <AsyncDisplayKit/ASCollectionView.h>
 #import <AsyncDisplayKit/ASCollectionNode.h>
-#import <AsyncDisplayKit/ASCollectionViewLayout.h>
 #import <AsyncDisplayKit/ASCollectionViewLayoutInspector.h>
 #import <AsyncDisplayKit/ASCollectionViewLayoutFacilitatorProtocol.h>
 #import <AsyncDisplayKit/ASCellNode.h>
 #import <AsyncDisplayKit/ASSectionContext.h>
 
+#import <AsyncDisplayKit/ASCollectionViewLayout.h>
 #import <AsyncDisplayKit/ASCollectionLayoutCalculating.h>
 #import <AsyncDisplayKit/ASCollectionLayoutSpecCalculator.h>
 #import <AsyncDisplayKit/ASCollectionFlowLayoutCalculator.h>
+#import <AsyncDisplayKit/ASLegacyCollectionLayoutCalculator.h>
 
 #import <AsyncDisplayKit/ASSectionController.h>
 #import <AsyncDisplayKit/ASSupplementaryNodeSource.h>

Source/Details/ASCollectionFlowLayoutCalculator.m

@@ -11,17 +11,13 @@
 #import <AsyncDisplayKit/ASCollectionElement.h>
 #import <AsyncDisplayKit/ASElementMap.h>
 #import <AsyncDisplayKit/ASStackLayoutSpec.h>
+#import <AsyncDisplayKit/ASBaseDefines.h>
 
 @implementation ASCollectionFlowLayoutCalculator
 
 - (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)sizeRange forElementMap:(ASElementMap *)map
 {
-  // TODO Use ASArrayByFlatMapping
-  NSMutableArray<ASCellNode *> *children = [NSMutableArray array];
-  for (ASCollectionElement *element in map) {
-    [children addObject:element.node];
-  }
-
+  NSArray<ASCellNode *> *children = ASArrayByFlatMapping(map, ASCollectionElement *element, element.node);
   ASStackLayoutSpec *stackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal
                                                                          spacing:0
                                                                   justifyContent:ASStackLayoutJustifyContentStart

Source/Details/ASCollectionLayoutCalculating.h

@@ -15,10 +15,17 @@ NS_ASSUME_NONNULL_BEGIN
 
 @protocol ASCollectionLayoutCalculating <NSObject>
 
+/**
+ * Whether or not size ranges must be provided via collection element in the element map.
+ * Default to NO, which means the calculator can determine size range for each collection element.
+ * ASLegacyCollectionLayoutCalculator might return YES because size ranges used to be provided via async delegate of table/collection view or layout inspector of collection view.
+ */
+@property (nonatomic, assign, readonly) BOOL sizeRangesShouldBeProvided;
+
 /**
  * @abstract Return a layout of elements.
  *
- * @param viewportSize The viewport size that the resulting layout should fit, usually equals to the bounds of the containing collection view.
+ * @param viewportSize The viewport size that the resulting layout should fit, usually equals to the bounds of the containing table/collection view.
  *
  * @param map An element map containings all elements to be laid out.
  *
@@ -31,7 +38,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @protocol ASCollectionLayoutCalculatorProviding <NSObject>
 
-- (nullable id<ASCollectionLayoutCalculating>)collectionViewLayoutCalculator;
+- (id<ASCollectionLayoutCalculating>)collectionLayoutCalculator;
 
 - (CGSize)viewportSizeForCollectionLayout;
 

Source/Details/ASCollectionLayoutSpecCalculator.m

@@ -12,6 +12,11 @@
 
 @implementation ASCollectionLayoutSpecCalculator
 
+- (BOOL)sizeRangesShouldBeProvided
+{
+  return NO;
+}
+
 - (instancetype)init
 {
   return [self initWithScrollableDirections:ASScrollDirectionVerticalDirections];

Source/Details/ASCollectionViewLayout.m

@@ -50,7 +50,7 @@ - (instancetype)initWithLayoutCalculator:(id<ASCollectionLayoutCalculating>)calc
 
 #pragma mark - ASCollectionLayoutCalculatorProviding
 
-- (id<ASCollectionLayoutCalculating>)collectionViewLayoutCalculator
+- (id<ASCollectionLayoutCalculating>)collectionLayoutCalculator
 {
   return _calculator;
 }

Source/Details/ASDataController.h

@@ -12,6 +12,7 @@
 
 #import <UIKit/UIKit.h>
 #import <AsyncDisplayKit/ASBlockTypes.h>
+#import <AsyncDisplayKit/ASCollectionLayoutCalculating.h>
 #import <AsyncDisplayKit/ASDimension.h>
 #import <AsyncDisplayKit/ASEventLog.h>
 #ifdef __cplusplus
@@ -46,7 +47,7 @@ extern NSString * const ASCollectionInvalidUpdateException;
  It will be invoked in the same thread as the api call of ASDataController.
  */
 
-@protocol ASDataControllerSource <NSObject>
+@protocol ASDataControllerSource <ASCollectionLayoutCalculatorProviding>
 
 /**
  Fetch the ASCellNode block for specific index path. This block should return the ASCellNode for the specified index path.
@@ -56,7 +57,6 @@ extern NSString * const ASCollectionInvalidUpdateException;
 /**
  The constrained size range for layout.
  */
-// TODO now that there is a layout calculator, this might be optional?
 - (ASSizeRange)dataController:(ASDataController *)dataController constrainedSizeForNodeAtIndexPath:(NSIndexPath *)indexPath;
 
 /**