TextureGroup · rcancro · Jul 26, 2023 · Jul 25, 2023
diff --git a/AsyncDisplayKit.xcodeproj/project.pbxproj b/AsyncDisplayKit.xcodeproj/project.pbxproj
@@ -213,6 +213,7 @@
 		9C49C3701B853961000B0DD5 /* ASStackLayoutElement.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C49C36E1B853957000B0DD5 /* ASStackLayoutElement.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		9C55866B1BD54A1900B50E3A /* ASAsciiArtBoxCreator.mm in Sources */ = {isa = PBXBuildFile; fileRef = 9C5586681BD549CB00B50E3A /* ASAsciiArtBoxCreator.mm */; };
 		9C55866C1BD54A3000B50E3A /* ASAsciiArtBoxCreator.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C5586671BD549CB00B50E3A /* ASAsciiArtBoxCreator.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		9C664E7D2A7048BE0059B2AB /* ASCellVisibilityScrollEventTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 9C664E7C2A7048BE0059B2AB /* ASCellVisibilityScrollEventTests.m */; };
 		9C6BB3B31B8CC9C200F13F52 /* ASAbsoluteLayoutElement.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C6BB3B01B8CC9C200F13F52 /* ASAbsoluteLayoutElement.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		9C70F2051CDA4F06007D6C76 /* ASTraitCollection.mm in Sources */ = {isa = PBXBuildFile; fileRef = 9C70F2021CDA4EFA007D6C76 /* ASTraitCollection.mm */; };
 		9C70F2061CDA4F0C007D6C76 /* ASTraitCollection.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C70F2011CDA4EFA007D6C76 /* ASTraitCollection.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -793,6 +794,7 @@
 		9C49C36E1B853957000B0DD5 /* ASStackLayoutElement.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASStackLayoutElement.h; sourceTree = "<group>"; };
 		9C5586671BD549CB00B50E3A /* ASAsciiArtBoxCreator.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASAsciiArtBoxCreator.h; sourceTree = "<group>"; };
 		9C5586681BD549CB00B50E3A /* ASAsciiArtBoxCreator.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASAsciiArtBoxCreator.mm; sourceTree = "<group>"; };
+		9C664E7C2A7048BE0059B2AB /* ASCellVisibilityScrollEventTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = ASCellVisibilityScrollEventTests.m; sourceTree = "<group>"; };
 		9C6BB3B01B8CC9C200F13F52 /* ASAbsoluteLayoutElement.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASAbsoluteLayoutElement.h; sourceTree = "<group>"; };
 		9C70F2011CDA4EFA007D6C76 /* ASTraitCollection.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASTraitCollection.h; sourceTree = "<group>"; };
 		9C70F2021CDA4EFA007D6C76 /* ASTraitCollection.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASTraitCollection.mm; sourceTree = "<group>"; };
@@ -1401,6 +1403,7 @@
 				CC583ABF1EF9BAB400134156 /* Common */,
 				058D09C6195D04C000B7D73C /* Supporting Files */,
 				052EE06A1A15A0D8002C6279 /* TestResources */,
+				9C664E7C2A7048BE0059B2AB /* ASCellVisibilityScrollEventTests.m */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
@@ -2341,6 +2344,7 @@
 				058D0A39195D057000B7D73C /* ASDisplayNodeAppearanceTests.mm in Sources */,
 				CCB2F34D1D63CCC6004E6DE9 /* ASDisplayNodeSnapshotTests.mm in Sources */,
 				AE6987C11DD04E1000B9E458 /* ASPagerNodeTests.mm in Sources */,
+				9C664E7D2A7048BE0059B2AB /* ASCellVisibilityScrollEventTests.m in Sources */,
 				058D0A3A195D057000B7D73C /* ASDisplayNodeTests.mm in Sources */,
 				9644CFE02193777C00213478 /* ASThrashUtility.m in Sources */,
 				696FCB311D6E46050093471E /* ASBackgroundLayoutSpecSnapshotTests.mm in Sources */,

diff --git a/Source/ASCellNode.h b/Source/ASCellNode.h
@@ -40,6 +40,11 @@ typedef NS_ENUM(NSUInteger, ASCellNodeVisibilityEvent) {
    * Indicates user has ended dragging the visible cell
    */
   ASCellNodeVisibilityEventDidEndDragging,
+  /**
+   * Indicates a cell has stopped scrolling. May not be called if
+   * ASCellNodeVisibilityEventDidEndDragging did not decelerate
+   */
+  ASCellNodeVisibilityEventDidStopScrolling,
 };
 
 /**

diff --git a/Source/ASCollectionView.mm b/Source/ASCollectionView.mm
@@ -1655,7 +1655,10 @@ - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoi
 - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
 {
   _deceleratingVelocity = CGPointZero;
-
+  for (_ASCollectionViewCell *cell in _cellsForVisibilityUpdates) {
+    [cell cellNodeVisibilityEvent:ASCellNodeVisibilityEventDidStopScrolling inScrollView:scrollView];
+  }
+
   if (_asyncDelegateFlags.scrollViewDidEndDecelerating) {
     [_asyncDelegate scrollViewDidEndDecelerating:scrollView];
   }

diff --git a/Source/ASTableView.mm b/Source/ASTableView.mm
@@ -1306,6 +1306,11 @@ - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
   }
   _deceleratingVelocity = CGPointZero;
 
+  for (_ASTableViewCell *tableViewCell in _cellsForVisibilityUpdates) {
+    [[tableViewCell node] cellNodeVisibilityEvent:ASCellNodeVisibilityEventDidStopScrolling
+                                          inScrollView:scrollView
+                                         withCellFrame:tableViewCell.frame];
+  }
   if (_asyncDelegateFlags.scrollViewDidEndDecelerating) {
       [_asyncDelegate scrollViewDidEndDecelerating:scrollView];
   }

diff --git a/Tests/ASCellVisibilityScrollEventTests.m b/Tests/ASCellVisibilityScrollEventTests.m
@@ -0,0 +1,222 @@
+//
+//  ASCellVisibilityScrollEventTests.m
+//  Texture
+//
+//  Copyright (c) Facebook, Inc. and its affiliates.  All rights reserved.
+//  Changes after 4/13/2017 are: Copyright (c) Pinterest, Inc.  All rights reserved.
+//  Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
+//
+
+#import <Foundation/Foundation.h>
+#import <XCTest/XCTest.h>
+
+#import <AsyncDisplayKit/AsyncDisplayKit.h>
+
+@interface ASCellVisibilityTestNode: ASTextCellNode
+@property (nonatomic) NSUInteger cellNodeVisibilityEventVisibleCount;
+@property (nonatomic) NSUInteger cellNodeVisibilityEventVisibleRectChangedCount;
+@property (nonatomic) NSUInteger cellNodeVisibilityEventInvisibleCount;
+@property (nonatomic) NSUInteger cellNodeVisibilityEventWillBeginDraggingCount;
+@property (nonatomic) NSUInteger cellNodeVisibilityEventDidEndDraggingCount;
+@property (nonatomic) NSUInteger cellNodeVisibilityEventDidStopScrollingCount;
+@end
+
+@implementation ASCellVisibilityTestNode
+
+- (void)cellNodeVisibilityEvent:(ASCellNodeVisibilityEvent)event inScrollView:(UIScrollView *)scrollView withCellFrame:(CGRect)cellFrame
+{
+  switch (event) {
+    case ASCellNodeVisibilityEventVisible:
+      self.cellNodeVisibilityEventVisibleCount++;
+      break;
+    case ASCellNodeVisibilityEventVisibleRectChanged:
+      self.cellNodeVisibilityEventVisibleRectChangedCount++;
+      break;
+    case ASCellNodeVisibilityEventInvisible:
+      self.cellNodeVisibilityEventInvisibleCount++;
+      break;
+    case ASCellNodeVisibilityEventWillBeginDragging:
+      self.cellNodeVisibilityEventWillBeginDraggingCount++;
+      break;
+    case ASCellNodeVisibilityEventDidEndDragging:
+      self.cellNodeVisibilityEventDidEndDraggingCount++;
+      break;
+    case ASCellNodeVisibilityEventDidStopScrolling:
+      self.cellNodeVisibilityEventDidStopScrollingCount++;
+      break;
+  }
+}
+
+@end
+
+@interface ASTableView (Private_Testing)
+- (void)scrollViewDidScroll:(UIScrollView *)scrollView;
+- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView;
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate;
+- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath;
+@end
+
+@interface ASCellVisibilityTableViewTestController: UIViewController<ASTableDataSource>
+
+@property (nonatomic) ASTableNode *tableNode;
+@property (nonatomic) ASTableView *tableView;
+
+@end
+
+@implementation ASCellVisibilityTableViewTestController
+
+- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
+  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
+  if (self) {
+    self.tableNode = [[ASTableNode alloc] init];
+    self.tableView = self.tableNode.view;
+    self.tableNode.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
+    self.tableNode.dataSource = self;
+
+    [self.view addSubview:self.tableView];
+  }
+  return self;
+}
+
+- (NSInteger)tableNode:(ASTableNode *)tableNode numberOfRowsInSection:(NSInteger)section
+{
+  return 1;
+}
+
+- (ASCellNodeBlock)tableNode:(ASTableNode *)tableNode nodeBlockForRowAtIndexPath:(NSIndexPath *)indexPath;
+{
+  return ^{
+    ASCellVisibilityTestNode *cell = [[ASCellVisibilityTestNode alloc] init];
+    return cell;
+  };
+}
+
+@end
+
+@interface ASCollectionView (Private_Testing)
+- (void)scrollViewDidScroll:(UIScrollView *)scrollView;
+- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView;
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate;
+- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)rawCell forItemAtIndexPath:(NSIndexPath *)indexPath;
+@end
+
+@interface ASCellVisibilityCollectionViewTestController: UIViewController<ASCollectionDataSource>
+
+@property (nonatomic) ASCollectionNode *collectionNode;
+@property (nonatomic) ASCollectionView *collectionView;
+
+@end
+
+@implementation ASCellVisibilityCollectionViewTestController
+
+- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
+  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
+  if (self) {
+    id realLayout = [UICollectionViewFlowLayout new];
+    self.collectionNode = [[ASCollectionNode alloc] initWithFrame:self.view.bounds collectionViewLayout:realLayout];
+    self.collectionView = self.collectionNode.view;
+    self.collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
+    self.collectionNode.dataSource = self;
+
+    [self.view addSubview:self.collectionView];
+  }
+  return self;
+}
+
+- (NSInteger)collectionNode:(ASCollectionNode *)collectionNode numberOfItemsInSection:(NSInteger)section
+{
+  return 1;
+}
+
+- (ASCellNodeBlock)collectionNode:(ASCollectionNode *)collectionNode nodeBlockForItemAtIndexPath:(NSIndexPath *)indexPath
+{
+  return ^{
+    ASCellVisibilityTestNode *cell = [[ASCellVisibilityTestNode alloc] init];
+    return cell;
+  };
+}
+
+@end
+
+
+@interface ASCellVisibilityScrollEventTests : XCTestCase
+@end
+
+@implementation ASCellVisibilityScrollEventTests
+
+- (void)testTableNodeEvents
+{
+  ASCellVisibilityTableViewTestController *testController = [[ASCellVisibilityTableViewTestController alloc] initWithNibName:nil bundle:nil];
+
+  UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+  [window setRootViewController:testController];
+  [window makeKeyAndVisible];
+
+  [testController.tableNode reloadData];
+  [testController.tableNode waitUntilAllUpdatesAreProcessed];
+  [testController.tableNode layoutIfNeeded];
+
+  ASTableView *tableView = testController.tableView;
+
+  NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
+  ASCellVisibilityTestNode *cell = (ASCellVisibilityTestNode *)[testController.tableNode nodeForRowAtIndexPath:indexPath];
+  UITableViewCell *uicell = [testController.tableNode cellForRowAtIndexPath:indexPath];
+
+  // Pretend the cell is appearing so it is added to _cellsForVisibilityUpdates
+  [tableView tableView:tableView willDisplayCell:uicell forRowAtIndexPath:indexPath];
+
+  // simulator scrollViewDidScroll so we can see if the cell got the event
+  [tableView scrollViewDidScroll:tableView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventVisibleRectChangedCount == 1);
+
+  [tableView scrollViewDidEndDecelerating:tableView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventDidStopScrollingCount == 1);
+
+  [tableView scrollViewWillBeginDragging:tableView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventWillBeginDraggingCount == 1);
+
+  [tableView scrollViewDidEndDragging:tableView willDecelerate:YES];
+  XCTAssertTrue(cell.cellNodeVisibilityEventDidEndDraggingCount == 1);
+
+}
+
+- (void)testCollectionNodeEvents
+{
+  ASCellVisibilityCollectionViewTestController *testController = [[ASCellVisibilityCollectionViewTestController alloc] initWithNibName:nil bundle:nil];
+
+  UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+  [window setRootViewController:testController];
+  [window makeKeyAndVisible];
+
+  [testController.collectionNode reloadData];
+  [testController.collectionNode waitUntilAllUpdatesAreProcessed];
+  [testController.collectionNode layoutIfNeeded];
+
+  ASCollectionView *collectionView = testController.collectionView;
+
+  NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
+  ASCellVisibilityTestNode *cell = (ASCellVisibilityTestNode *)[testController.collectionNode nodeForItemAtIndexPath:indexPath];
+  UICollectionViewCell *uicell = [testController.collectionNode cellForItemAtIndexPath:indexPath];
+
+  // Pretend the cell is appearing so it is added to _cellsForVisibilityUpdates
+  [collectionView collectionView:collectionView willDisplayCell:uicell forItemAtIndexPath:indexPath];
+
+  // simulator scrollViewDidScroll so we can see if the cell got the event
+  [collectionView scrollViewDidScroll:collectionView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventVisibleRectChangedCount == 1);
+
+  [collectionView scrollViewDidEndDecelerating:collectionView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventDidStopScrollingCount == 1);
+
+  [collectionView scrollViewWillBeginDragging:collectionView];
+  XCTAssertTrue(cell.cellNodeVisibilityEventWillBeginDraggingCount == 1);
+
+  [collectionView scrollViewDidEndDragging:collectionView willDecelerate:YES];
+  XCTAssertTrue(cell.cellNodeVisibilityEventDidEndDraggingCount == 1);
+}
+
+
+@end
+