Merge pull request #529 from facebook/DataControllerQueues

Overhaul ASDataController and extensively test ASTableView.

Author: appleguy

AsyncDisplayKit/ASDisplayNode.mm

@@ -1337,6 +1337,7 @@ - (void)clearContents
 {
   self.layer.contents = nil;
   _placeholderLayer.contents = nil;
+  _placeholderImage = nil;
 }
 
 - (void)recursivelyClearContents

AsyncDisplayKit/ASTableView.mm

@@ -10,7 +10,7 @@
 
 #import "ASAssert.h"
 #import "ASDataController.h"
-#import "ASFlowLayoutController.h"
+#import "ASCollectionViewLayoutController.h"
 #import "ASLayoutController.h"
 #import "ASRangeController.h"
 #import "ASDisplayNodeInternal.h"
@@ -160,14 +160,16 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
 - (void)configureWithAsyncDataFetching:(BOOL)asyncDataFetchingEnabled
 {
   _layoutController = [[ASFlowLayoutController alloc] initWithScrollOption:ASFlowLayoutDirectionVertical];
-
+  
   _rangeController = [[ASRangeController alloc] init];
   _rangeController.layoutController = _layoutController;
   _rangeController.delegate = self;
 
   _dataController = [[ASDataController alloc] initWithAsyncDataFetching:asyncDataFetchingEnabled];
   _dataController.dataSource = self;
   _dataController.delegate = _rangeController;
+  
+  _layoutController.dataSource = _dataController;
 
   _asyncDataFetchingEnabled = asyncDataFetchingEnabled;
   _asyncDataSourceLocked = NO;
@@ -417,20 +419,12 @@ - (ASScrollDirection)scrollDirection
 {
   CGPoint scrollVelocity = [self.panGestureRecognizer velocityInView:self.superview];
   ASScrollDirection direction = ASScrollDirectionNone;
-  if (_layoutController.layoutDirection == ASFlowLayoutDirectionHorizontal) {
-    if (scrollVelocity.x > 0) {
-      direction = ASScrollDirectionRight;
-    } else if (scrollVelocity.x < 0) {
-      direction = ASScrollDirectionLeft;
-    }
+  if (scrollVelocity.y > 0) {
+    direction = ASScrollDirectionDown;
   } else {
-    if (scrollVelocity.y > 0) {
-      direction = ASScrollDirectionDown;
-    } else {
-      direction = ASScrollDirectionUp;
-    }
+    direction = ASScrollDirectionUp;
   }
-
+  
   return direction;
 }
 

AsyncDisplayKit/Details/ASCollectionViewLayoutController.mm

@@ -21,7 +21,8 @@
 typedef struct ASDirectionalScreenfulBuffer ASDirectionalScreenfulBuffer;
 
 ASDirectionalScreenfulBuffer ASDirectionalScreenfulBufferHorizontal(ASScrollDirection scrollDirection,
-                                                                    ASRangeTuningParameters rangeTuningParameters) {
+                                                                    ASRangeTuningParameters rangeTuningParameters)
+{
   ASDirectionalScreenfulBuffer horizontalBuffer = {0, 0};
   BOOL movingRight = ASScrollDirectionContainsRight(scrollDirection);
   horizontalBuffer.positiveDirection = movingRight ? rangeTuningParameters.leadingBufferScreenfuls :
@@ -32,7 +33,8 @@ ASDirectionalScreenfulBuffer ASDirectionalScreenfulBufferHorizontal(ASScrollDire
 }
 
 ASDirectionalScreenfulBuffer ASDirectionalScreenfulBufferVertical(ASScrollDirection scrollDirection,
-                                                                  ASRangeTuningParameters rangeTuningParameters) {
+                                                                  ASRangeTuningParameters rangeTuningParameters)
+{
   ASDirectionalScreenfulBuffer verticalBuffer = {0, 0};
   BOOL movingDown = ASScrollDirectionContainsDown(scrollDirection);
   verticalBuffer.positiveDirection = movingDown ? rangeTuningParameters.leadingBufferScreenfuls :
@@ -52,19 +54,26 @@ ASDirectionalScreenfulBuffer ASDirectionalScreenfulBufferVertical(ASScrollDirect
 #pragma mark -
 #pragma mark ASCollectionViewLayoutController
 
-@interface ASCollectionViewLayoutController () {
-  ASCollectionView * __weak _collectionView;
+@interface ASCollectionViewLayoutController ()
+{
+  UIScrollView * __weak _scrollView;
+  UICollectionViewLayout * __strong _collectionViewLayout;
   std::vector<CGRect> _updateRangeBoundsIndexedByRangeType;
+  ASScrollDirection _scrollableDirections;
 }
 @end
 
 @implementation ASCollectionViewLayoutController
 
-- (instancetype)initWithCollectionView:(ASCollectionView *)collectionView {
+- (instancetype)initWithCollectionView:(ASCollectionView *)collectionView
+{
   if (!(self = [super init])) {
     return nil;
   }
-  _collectionView = collectionView;
+  
+  _scrollableDirections = [collectionView scrollableDirections];
+  _scrollView = collectionView;
+  _collectionViewLayout = [collectionView collectionViewLayout];
   _updateRangeBoundsIndexedByRangeType = std::vector<CGRect>(ASLayoutRangeTypeCount);
   return self;
 }
@@ -74,22 +83,21 @@ - (instancetype)initWithCollectionView:(ASCollectionView *)collectionView {
 
 - (NSSet *)indexPathsForScrolling:(ASScrollDirection)scrollDirection
                      viewportSize:(CGSize)viewportSize
-                        rangeType:(ASLayoutRangeType)rangeType {
+                        rangeType:(ASLayoutRangeType)rangeType
+{
   ASRangeGeometry rangeGeometry = [self rangeGeometryWithScrollDirection:scrollDirection
-                                                          collectionView:_collectionView
                                                    rangeTuningParameters:[self tuningParametersForRangeType:rangeType]];
   _updateRangeBoundsIndexedByRangeType[rangeType] = rangeGeometry.updateBounds;
-  return [self indexPathsForItemsWithinRangeBounds:rangeGeometry.rangeBounds collectionView:_collectionView];
+  return [self indexPathsForItemsWithinRangeBounds:rangeGeometry.rangeBounds];
 }
 
 - (ASRangeGeometry)rangeGeometryWithScrollDirection:(ASScrollDirection)scrollDirection
-                                     collectionView:(ASCollectionView *)collectionView
-                              rangeTuningParameters:(ASRangeTuningParameters)rangeTuningParameters {
-  CGRect rangeBounds = collectionView.bounds;
-  CGRect updateBounds = collectionView.bounds;
-  ASScrollDirection scrollableDirections = [collectionView scrollableDirections];
+                              rangeTuningParameters:(ASRangeTuningParameters)rangeTuningParameters
+{
+  CGRect rangeBounds = _scrollView.bounds;
+  CGRect updateBounds = _scrollView.bounds;
 
-  BOOL canScrollHorizontally = ASScrollDirectionContainsHorizontalDirection(scrollableDirections);
+  BOOL canScrollHorizontally = ASScrollDirectionContainsHorizontalDirection(_scrollableDirections);
   if (canScrollHorizontally) {
     ASDirectionalScreenfulBuffer horizontalBuffer = ASDirectionalScreenfulBufferHorizontal(scrollDirection,
                                                                                            rangeTuningParameters);
@@ -102,7 +110,7 @@ - (ASRangeGeometry)rangeGeometryWithScrollDirection:(ASScrollDirection)scrollDir
                                                  MIN(horizontalBuffer.positiveDirection * 0.5, 0.95));
   }
 
-  BOOL canScrollVertically = ASScrollDirectionContainsVerticalDirection(scrollableDirections);
+  BOOL canScrollVertically = ASScrollDirectionContainsVerticalDirection(_scrollableDirections);
   if (canScrollVertically) {
     ASDirectionalScreenfulBuffer verticalBuffer = ASDirectionalScreenfulBufferVertical(scrollDirection,
                                                                                        rangeTuningParameters);
@@ -118,9 +126,10 @@ - (ASRangeGeometry)rangeGeometryWithScrollDirection:(ASScrollDirection)scrollDir
   return {rangeBounds, updateBounds};
 }
 
-- (NSSet *)indexPathsForItemsWithinRangeBounds:(CGRect)rangeBounds collectionView:(ASCollectionView *)collectionView {
+- (NSSet *)indexPathsForItemsWithinRangeBounds:(CGRect)rangeBounds
+{
   NSMutableSet *indexPathSet = [[NSMutableSet alloc] init];
-  NSArray *layoutAttributes = [collectionView.collectionViewLayout layoutAttributesForElementsInRect:rangeBounds];
+  NSArray *layoutAttributes = [_collectionViewLayout layoutAttributesForElementsInRect:rangeBounds];
   for (UICollectionViewLayoutAttributes *la in layoutAttributes) {
     [indexPathSet addObject:la.indexPath];
   }
@@ -132,13 +141,14 @@ - (NSSet *)indexPathsForItemsWithinRangeBounds:(CGRect)rangeBounds collectionVie
 
 - (BOOL)shouldUpdateForVisibleIndexPaths:(NSArray *)indexPaths
                             viewportSize:(CGSize)viewportSize
-                               rangeType:(ASLayoutRangeType)rangeType {
+                               rangeType:(ASLayoutRangeType)rangeType
+{
   CGRect updateRangeBounds = _updateRangeBoundsIndexedByRangeType[rangeType];
   if (CGRectIsEmpty(updateRangeBounds)) {
     return YES;
   }
 
-  CGRect currentBounds = _collectionView.bounds;
+  CGRect currentBounds = _scrollView.bounds;
   if (CGRectIsEmpty(currentBounds)) {
     currentBounds = CGRectMake(0, 0, viewportSize.width, viewportSize.height);
   }

AsyncDisplayKit/Details/ASDataController.h

@@ -8,7 +8,7 @@
 
 #import <UIKit/UIKit.h>
 #import <AsyncDisplayKit/ASDealloc2MainObject.h>
-
+#import "ASFlowLayoutController.h"
 
 @class ASCellNode;
 @class ASDataController;
@@ -70,25 +70,21 @@ typedef NSUInteger ASDataControllerAnimationOptions;
 /**
  Called for insertion of elements.
  */
-- (void)dataController:(ASDataController *)dataController willInsertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 - (void)dataController:(ASDataController *)dataController didInsertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 
 /**
  Called for deletion of elements.
  */
-- (void)dataController:(ASDataController *)dataController willDeleteNodesAtIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 - (void)dataController:(ASDataController *)dataController didDeleteNodesAtIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 
 /**
  Called for insertion of sections.
  */
-- (void)dataController:(ASDataController *)dataController willInsertSections:(NSArray *)sections atIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 - (void)dataController:(ASDataController *)dataController didInsertSections:(NSArray *)sections atIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 
 /**
  Called for deletion of sections.
  */
-- (void)dataController:(ASDataController *)dataController willDeleteSectionsAtIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 - (void)dataController:(ASDataController *)dataController didDeleteSectionsAtIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 
 @end
@@ -101,7 +97,8 @@ typedef NSUInteger ASDataControllerAnimationOptions;
  * will be updated asynchronously. The dataSource must be updated to reflect the changes before these methods has been called.
  * For each data updatin, the corresponding methods in delegate will be called.
  */
-@interface ASDataController : ASDealloc2MainObject
+@protocol ASFlowLayoutControllerDataSource;
+@interface ASDataController : ASDealloc2MainObject <ASFlowLayoutControllerDataSource>
 
 /**
  Data source for fetching data info.
@@ -117,7 +114,7 @@ typedef NSUInteger ASDataControllerAnimationOptions;
  *  Designated iniailizer.
  *
  * @param asyncDataFetchingEnabled Enable the data fetching in async mode.
- 
+ *
  * @discussion If enabled, we will fetch data through `dataController:nodeAtIndexPath:` and `dataController:rowsInSection:` in background thread.
  * Otherwise, the methods will be invoked synchronically in calling thread. Enabling data fetching in async mode could avoid blocking main thread
  * while allocating cell on main thread, which is frequently reported issue for handling large scale data. On another hand, the application code
@@ -127,7 +124,11 @@ typedef NSUInteger ASDataControllerAnimationOptions;
  */
 - (instancetype)initWithAsyncDataFetching:(BOOL)asyncDataFetchingEnabled;
 
-/** @name Initial loading */
+/** @name Initial loading
+ *
+ * @discussion This method allows choosing an animation style for the first load of content.  It is typically used just once,
+ * for example in viewWillAppear:, to specify an animation option for the information already present in the asyncDataSource.
+ */
 
 - (void)initialDataLoadingWithAnimationOptions:(ASDataControllerAnimationOptions)animationOptions;
 
@@ -167,4 +168,6 @@ typedef NSUInteger ASDataControllerAnimationOptions;
 
 - (NSArray *)nodesAtIndexPaths:(NSArray *)indexPaths;
 
+- (NSArray *)completedNodes;  // This provides efficient access to the entire _completedNodes multidimensional array.
+
 @end