[ASCellNode] Adding support for scroll view begin / end drag to VisibilityEvent changes.

Author: appleguy

AsyncDisplayKit/ASCollectionView.mm

@@ -133,6 +133,8 @@ @interface ASCollectionView () <ASRangeControllerDataSource, ASRangeControllerDe
 
   struct {
     unsigned int asyncDelegateScrollViewDidScroll:1;
+    unsigned int asyncDelegateScrollViewWillBeginDragging:1;
+    unsigned int asyncDelegateScrollViewDidEndDragging:1;
     unsigned int asyncDelegateScrollViewWillEndDraggingWithVelocityTargetContentOffset:1;
     unsigned int asyncDelegateCollectionViewWillDisplayNodeForItemAtIndexPath:1;
     unsigned int asyncDelegateCollectionViewDidEndDisplayingNodeForItemAtIndexPath:1;
@@ -396,6 +398,8 @@ - (void)setAsyncDelegate:(id<ASCollectionViewDelegate>)asyncDelegate
     _asyncDelegateFlags.asyncDelegateCollectionViewDidEndDisplayingNodeForItemAtIndexPath = [_asyncDelegate respondsToSelector:@selector(collectionView:didEndDisplayingNode:forItemAtIndexPath:)];
     _asyncDelegateFlags.asyncDelegateCollectionViewWillBeginBatchFetchWithContext = [_asyncDelegate respondsToSelector:@selector(collectionView:willBeginBatchFetchWithContext:)];
     _asyncDelegateFlags.asyncDelegateShouldBatchFetchForCollectionView = [_asyncDelegate respondsToSelector:@selector(shouldBatchFetchForCollectionView:)];
+    _asyncDelegateFlags.asyncDelegateScrollViewWillBeginDragging = [_asyncDelegate respondsToSelector:@selector(scrollViewWillBeginDragging:)];
+    _asyncDelegateFlags.asyncDelegateScrollViewDidEndDragging = [_asyncDelegate respondsToSelector:@selector(scrollViewDidEndDragging:willDecelerate:)];
   }
 
   super.delegate = (id<UICollectionViewDelegate>)_proxyDelegate;
@@ -672,6 +676,29 @@ - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoi
   }
 }
 
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
+{
+  for (_ASCollectionViewCell *collectionCell in _cellsForVisibilityUpdates) {
+    [[collectionCell node] cellNodeVisibilityEvent:ASCellNodeVisibilityEventWillBeginDragging
+                                          inScrollView:scrollView
+                                         withCellFrame:collectionCell.frame];
+  }
+  if (_asyncDelegateFlags.asyncDelegateScrollViewWillBeginDragging) {
+    [_asyncDelegate scrollViewWillBeginDragging:scrollView];
+  }
+}
+
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
+{
+    for (_ASCollectionViewCell *collectionCell in _cellsForVisibilityUpdates) {
+        [[collectionCell node] cellNodeVisibilityEvent:ASCellNodeVisibilityEventDidEndDragging
+                                          inScrollView:scrollView
+                                         withCellFrame:collectionCell.frame];
+    }
+    if (_asyncDelegateFlags.asyncDelegateScrollViewDidEndDragging) {
+        [_asyncDelegate scrollViewDidEndDragging:scrollView willDecelerate:decelerate];
+    }
+}
 
 #pragma mark - Scroll Direction.
 

AsyncDisplayKit/ASTableView.mm

@@ -117,6 +117,8 @@ @interface ASTableView () <ASRangeControllerDataSource, ASRangeControllerDelegat
 
   struct {
     unsigned int asyncDelegateScrollViewDidScroll:1;
+    unsigned int asyncDelegateScrollViewWillBeginDragging:1;
+    unsigned int asyncDelegateScrollViewDidEndDragging:1;
     unsigned int asyncDelegateTableViewWillDisplayNodeForRowAtIndexPath:1;
     unsigned int asyncDelegateTableViewDidEndDisplayingNodeForRowAtIndexPath:1;
     unsigned int asyncDelegateTableViewDidEndDisplayingNodeForRowAtIndexPathDeprecated:1;
@@ -320,6 +322,8 @@ - (void)setAsyncDelegate:(id<ASTableViewDelegate>)asyncDelegate
     _asyncDelegateFlags.asyncDelegateScrollViewWillEndDraggingWithVelocityTargetContentOffset = [_asyncDelegate respondsToSelector:@selector(scrollViewWillEndDragging:withVelocity:targetContentOffset:)];
     _asyncDelegateFlags.asyncDelegateTableViewWillBeginBatchFetchWithContext = [_asyncDelegate respondsToSelector:@selector(tableView:willBeginBatchFetchWithContext:)];
     _asyncDelegateFlags.asyncDelegateShouldBatchFetchForTableView = [_asyncDelegate respondsToSelector:@selector(shouldBatchFetchForTableView:)];
+    _asyncDelegateFlags.asyncDelegateScrollViewWillBeginDragging = [_asyncDelegate respondsToSelector:@selector(scrollViewWillBeginDragging:)];
+    _asyncDelegateFlags.asyncDelegateScrollViewDidEndDragging = [_asyncDelegate respondsToSelector:@selector(scrollViewDidEndDragging:willDecelerate:)];
   }
 
   super.delegate = (id<UITableViewDelegate>)_proxyDelegate;
@@ -697,6 +701,29 @@ - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoi
   }
 }
 
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
+{
+  for (_ASTableViewCell *tableViewCell in _cellsForVisibilityUpdates) {
+    [[tableViewCell node] cellNodeVisibilityEvent:ASCellNodeVisibilityEventWillBeginDragging
+                                          inScrollView:scrollView
+                                         withCellFrame:tableViewCell.frame];
+  }
+  if (_asyncDelegateFlags.asyncDelegateScrollViewWillBeginDragging) {
+    [_asyncDelegate scrollViewWillBeginDragging:scrollView];
+  }
+}
+
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
+{
+  for (_ASTableViewCell *tableViewCell in _cellsForVisibilityUpdates) {
+    [[tableViewCell node] cellNodeVisibilityEvent:ASCellNodeVisibilityEventDidEndDragging
+                                          inScrollView:scrollView
+                                         withCellFrame:tableViewCell.frame];
+  }
+  if (_asyncDelegateFlags.asyncDelegateScrollViewDidEndDragging) {
+    [_asyncDelegate scrollViewDidEndDragging:scrollView willDecelerate:decelerate];
+  }
+}
 
 #pragma mark - Scroll Direction
 

AsyncDisplayKit/Details/ASDelegateProxy.m

@@ -26,6 +26,10 @@ - (BOOL)interceptsSelector:(SEL)selector
 
           // used for ASCellNode visibility
           selector == @selector(scrollViewDidScroll:) ||
+
+          // used for ASCellNode user interaction
+          selector == @selector(scrollViewWillBeginDragging:) ||
+          selector == @selector(scrollViewDidEndDragging:willDecelerate:) ||
 
           // used for ASRangeController visibility updates
           selector == @selector(tableView:willDisplayCell:forRowAtIndexPath:) ||
@@ -61,6 +65,10 @@ - (BOOL)interceptsSelector:(SEL)selector
 
           // used for ASCellNode visibility
           selector == @selector(scrollViewDidScroll:) ||
+
+          // used for ASCellNode user interaction
+          selector == @selector(scrollViewWillBeginDragging:) ||
+          selector == @selector(scrollViewDidEndDragging:willDecelerate:) ||
 
           // intercepted due to not being supported by ASCollectionView (prevent bugs caused by usage)
           selector == @selector(collectionView:canMoveItemAtIndexPath:) ||