Merge pull request #1064 from binl/bl_layout_facilitator_change

Initial implementation of ASCollectionNode's LayoutFacilitator to help apps optimize custom layouts.

Author: appleguy

AsyncDisplayKit.xcodeproj/project.pbxproj

@@ -357,6 +357,8 @@
 		ACF6ED631B178DC700DA7C62 /* ASStackLayoutSpecSnapshotTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = ACF6ED5B1B178DC700DA7C62 /* ASStackLayoutSpecSnapshotTests.mm */; };
 		B0F8805A1BEAEC7500D17647 /* ASTableNode.h in Headers */ = {isa = PBXBuildFile; fileRef = B0F880581BEAEC7500D17647 /* ASTableNode.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		B0F8805B1BEAEC7500D17647 /* ASTableNode.m in Sources */ = {isa = PBXBuildFile; fileRef = B0F880591BEAEC7500D17647 /* ASTableNode.m */; };
+		B13CA0F71C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h in Headers */ = {isa = PBXBuildFile; fileRef = B13CA0F61C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h */; };
+		B13CA0F81C519EBA00E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h in Headers */ = {isa = PBXBuildFile; fileRef = B13CA0F61C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h */; };
 		B35061F31B010EFD0018CF92 /* ASCellNode.h in Headers */ = {isa = PBXBuildFile; fileRef = 055F1A3A19ABD43F004DAFF1 /* ASCellNode.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		B35061F51B010EFD0018CF92 /* ASCollectionView.h in Headers */ = {isa = PBXBuildFile; fileRef = AC3C4A4F1A1139C100143C57 /* ASCollectionView.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		B35061F61B010EFD0018CF92 /* ASCollectionView.mm in Sources */ = {isa = PBXBuildFile; fileRef = AC3C4A501A1139C100143C57 /* ASCollectionView.mm */; };
@@ -765,6 +767,7 @@
 		ACF6ED5B1B178DC700DA7C62 /* ASStackLayoutSpecSnapshotTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASStackLayoutSpecSnapshotTests.mm; sourceTree = "<group>"; };
 		B0F880581BEAEC7500D17647 /* ASTableNode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASTableNode.h; sourceTree = "<group>"; };
 		B0F880591BEAEC7500D17647 /* ASTableNode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASTableNode.m; sourceTree = "<group>"; };
+		B13CA0F61C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASCollectionViewLayoutFacilitatorProtocol.h; sourceTree = "<group>"; };
 		B35061DA1B010EDF0018CF92 /* AsyncDisplayKit.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = AsyncDisplayKit.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		B35061DD1B010EDF0018CF92 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; name = Info.plist; path = "../AsyncDisplayKit-iOS/Info.plist"; sourceTree = "<group>"; };
 		CC7FD9DC1BB5E962005CCB2B /* ASPhotosFrameworkImageRequest.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASPhotosFrameworkImageRequest.h; sourceTree = "<group>"; };
@@ -908,6 +911,7 @@
 				AC3C4A4F1A1139C100143C57 /* ASCollectionView.h */,
 				AC3C4A501A1139C100143C57 /* ASCollectionView.mm */,
 				AC3C4A531A113EEC00143C57 /* ASCollectionViewProtocols.h */,
+				B13CA0F61C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h */,
 				DEC146B41C37A16A004A0EE7 /* ASCollectionInternal.h */,
 				DEC146B51C37A16A004A0EE7 /* ASCollectionInternal.m */,
 				058D09D5195D050800B7D73C /* ASControlNode.h */,
@@ -1276,6 +1280,7 @@
 				058D0A72195D05F800B7D73C /* _ASCoreAnimationExtras.h in Headers */,
 				058D0A53195D05DC00B7D73C /* _ASDisplayLayer.h in Headers */,
 				058D0A55195D05DC00B7D73C /* _ASDisplayView.h in Headers */,
+				B13CA0F71C519E9400E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h in Headers */,
 				058D0A74195D05F800B7D73C /* _ASPendingState.h in Headers */,
 				9C5586691BD549CB00B50E3A /* ASAsciiArtBoxCreator.h in Headers */,
 				058D0A76195D05F900B7D73C /* _ASScopeTimer.h in Headers */,
@@ -1474,6 +1479,7 @@
 				B35062041B010EFD0018CF92 /* ASMultiplexImageNode.h in Headers */,
 				DECBD6E81BE56E1900CF4905 /* ASButtonNode.h in Headers */,
 				B35062241B010EFD0018CF92 /* ASMutableAttributedStringBuilder.h in Headers */,
+				B13CA0F81C519EBA00E031AB /* ASCollectionViewLayoutFacilitatorProtocol.h in Headers */,
 				B35062061B010EFD0018CF92 /* ASNetworkImageNode.h in Headers */,
 				34EFC76C1B701CED00AD841F /* ASOverlayLayoutSpec.h in Headers */,
 				B35062261B010EFD0018CF92 /* ASRangeController.h in Headers */,

AsyncDisplayKit/ASCollectionNode.h

@@ -8,6 +8,8 @@
 
 #import <AsyncDisplayKit/ASCollectionView.h>
 
+@protocol ASCollectionViewLayoutFacilitatorProtocol;
+
 NS_ASSUME_NONNULL_BEGIN
 
 /**
@@ -18,6 +20,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout *)layout;
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout;
+- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(nullable id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator;
 
 @property (weak, nonatomic) id <ASCollectionDelegate>   delegate;
 @property (weak, nonatomic) id <ASCollectionDataSource> dataSource;

AsyncDisplayKit/ASCollectionNode.mm

@@ -8,6 +8,7 @@
 
 #import "ASCollectionNode.h"
 #import "ASCollectionInternal.h"
+#import "ASCollectionViewLayoutFacilitatorProtocol.h"
 #import "ASDisplayNode+Subclasses.h"
 #import "ASRangeController.h"
 #include <vector>
@@ -83,9 +84,14 @@ - (instancetype)_initWithCollectionView:(ASCollectionView *)collectionView
 }
 
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout
+{
+  return [self initWithFrame:frame collectionViewLayout:layout layoutFacilitator:nil];
+}
+
+- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator
 {
   ASDisplayNodeViewBlock collectionViewBlock = ^UIView *{
-    return [[ASCollectionView alloc] _initWithFrame:frame collectionViewLayout:layout ownedByNode:YES];
+    return [[ASCollectionView alloc] _initWithFrame:CGRectZero collectionViewLayout:layout layoutFacilitator:layoutFacilitator ownedByNode:YES];
   };
 
   if (self = [super initWithViewBlock:collectionViewBlock]) {

AsyncDisplayKit/ASCollectionView.h

@@ -19,6 +19,7 @@
 @protocol ASCollectionDataSource;
 @protocol ASCollectionDelegate;
 @protocol ASCollectionViewLayoutInspecting;
+@protocol ASCollectionViewLayoutFacilitatorProtocol;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -43,6 +44,7 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout *)layout;
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout;
+- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator;
 
 // The corresponding ASCollectionNode, which exists even if directly allocating & handling the view class.
 @property (nonatomic, weak, readonly) ASCollectionNode *collectionNode;

AsyncDisplayKit/ASCollectionView.mm

@@ -13,6 +13,7 @@
 #import "ASCollectionDataController.h"
 #import "ASCollectionViewLayoutController.h"
 #import "ASCollectionViewFlowLayoutInspector.h"
+#import "ASCollectionViewLayoutFacilitatorProtocol.h"
 #import "ASDisplayNode+FrameworkPrivate.h"
 #import "ASDisplayNode+Beta.h"
 #import "ASInternalHelpers.h"
@@ -67,6 +68,8 @@ @interface ASCollectionView () <ASRangeControllerDataSource, ASRangeControllerDe
   ASRangeController *_rangeController;
   ASCollectionViewLayoutController *_layoutController;
   ASCollectionViewFlowLayoutInspector *_flowLayoutInspector;
+    
+  id<ASCollectionViewLayoutFacilitatorProtocol> _layoutFacilitator;
 
   BOOL _performingBatchUpdates;
   NSMutableArray *_batchUpdateBlocks;
@@ -137,13 +140,25 @@ - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionVi
   return [self _initWithFrame:frame collectionViewLayout:layout ownedByNode:NO];
 }
 
+- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator
+{
+  self = [self _initWithFrame:frame collectionViewLayout:layout ownedByNode:NO];
+  _layoutFacilitator = layoutFacilitator;
+  return self;
+}
+
 // FIXME: This method is deprecated and will probably be removed in or shortly after 2.0.
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout asyncDataFetching:(BOOL)asyncDataFetchingEnabled
 {
   return [self _initWithFrame:frame collectionViewLayout:layout ownedByNode:NO];
 }
 
 - (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout ownedByNode:(BOOL)ownedByNode
+{
+  return [self _initWithFrame:frame collectionViewLayout:layout layoutFacilitator:nil ownedByNode:ownedByNode];
+}
+
+- (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator ownedByNode:(BOOL)ownedByNode
 {
   if (!(self = [super initWithFrame:frame collectionViewLayout:layout]))
     return nil;
@@ -195,6 +210,7 @@ - (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionV
   if ([layout asdk_isFlowLayout]) {
     _layoutInspector = [self flowLayoutInspector];
   }
+  _layoutFacilitator = layoutFacilitator;
 
   _proxyDelegate = [[ASCollectionViewProxy alloc] initWithTarget:nil interceptor:self];
   super.delegate = (id<UICollectionViewDelegate>)_proxyDelegate;
@@ -833,7 +849,7 @@ - (void)didBeginUpdatesInRangeController:(ASRangeController *)rangeController
 - (void)rangeController:(ASRangeController *)rangeController didEndUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL))completion
 {
   ASDisplayNodeAssertMainThread();
-  
+
   if (!self.asyncDataSource || _superIsPendingDataLoad) {
     if (completion) {
       completion(NO);
@@ -856,7 +872,7 @@ - (void)rangeController:(ASRangeController *)rangeController didEndUpdatesAnimat
 - (void)rangeController:(ASRangeController *)rangeController didInsertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
-  
+  [_layoutFacilitator collectionViewEditingCellsAtIndexPaths:indexPaths];
   if (!self.asyncDataSource || _superIsPendingDataLoad) {
     return; // if the asyncDataSource has become invalid while we are processing, ignore this request to avoid crashes
   }
@@ -875,7 +891,7 @@ - (void)rangeController:(ASRangeController *)rangeController didInsertNodes:(NSA
 - (void)rangeController:(ASRangeController *)rangeController didDeleteNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
-  
+  [_layoutFacilitator collectionViewEditingCellsAtIndexPaths:indexPaths];
   if (!self.asyncDataSource || _superIsPendingDataLoad) {
     return; // if the asyncDataSource has become invalid while we are processing, ignore this request to avoid crashes
   }
@@ -894,7 +910,7 @@ - (void)rangeController:(ASRangeController *)rangeController didDeleteNodes:(NSA
 - (void)rangeController:(ASRangeController *)rangeController didInsertSectionsAtIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
-  
+  [_layoutFacilitator collectionViewEditingSectionsAtIndexSet:indexSet];
   if (!self.asyncDataSource || _superIsPendingDataLoad) {
     return; // if the asyncDataSource has become invalid while we are processing, ignore this request to avoid crashes
   }
@@ -913,7 +929,7 @@ - (void)rangeController:(ASRangeController *)rangeController didInsertSectionsAt
 - (void)rangeController:(ASRangeController *)rangeController didDeleteSectionsAtIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
-  
+  [_layoutFacilitator collectionViewEditingSectionsAtIndexSet:indexSet];
   if (!self.asyncDataSource || _superIsPendingDataLoad) {
     return; // if the asyncDataSource has become invalid while we are processing, ignore this request to avoid crashes
   }

AsyncDisplayKit/ASCollectionViewLayoutFacilitatorProtocol.h

@@ -0,0 +1,30 @@
+/* Copyright (c) 2014-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.
+ */
+
+#ifndef ASCollectionViewLayoutFacilitatorProtocol_h
+#define ASCollectionViewLayoutFacilitatorProtocol_h
+
+/**
+ * This facilitator protocol is intended to help Layout to better
+ * gel with the CollectionView
+ */
+@protocol ASCollectionViewLayoutFacilitatorProtocol <NSObject>
+
+/**
+ * Inform that the collectionView is editing the cells at a list of indexPaths
+ */
+- (void)collectionViewEditingCellsAtIndexPaths:(NSArray *)indexPaths;
+
+/**
+ * Inform that the collectionView is editing the sections at a set of indexes
+ */
+- (void)collectionViewEditingSectionsAtIndexSet:(NSIndexSet *)indexes;
+
+@end
+
+#endif /* ASCollectionViewLayoutFacilitatorProtocol_h */

AsyncDisplayKit/Details/ASCollectionInternal.h

@@ -11,7 +11,7 @@
 #import "ASRangeController.h"
 
 @interface ASCollectionView ()
-- (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout ownedByNode:(BOOL)ownedByNode;
+- (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator ownedByNode:(BOOL)ownedByNode;
 
 @property (nonatomic, weak, readwrite) ASCollectionNode *collectionNode;
 @property (nonatomic, strong, readonly) ASRangeController *rangeController;