Instagram · rnystrom · Dec 5, 2016 · Dec 5, 2016
diff --git a/IGListKit.xcodeproj/project.pbxproj b/IGListKit.xcodeproj/project.pbxproj
@@ -455,12 +455,12 @@
 				8285404F1DE40D2D00118B94 /* IGListTestAdapterHorizontalDataSource.m */,
 				8240C7F91DC2F6CF00B3AAE7 /* IGListTestAdapterStoryboardDataSource.h */,
 				8240C7FA1DC2F6CF00B3AAE7 /* IGListTestAdapterStoryboardDataSource.m */,
+				8285404A1DE40C6E00118B94 /* IGListTestHorizontalSection.h */,
+				8285404B1DE40C6E00118B94 /* IGListTestHorizontalSection.m */,
 				88144EF31D870EDC007C7F66 /* IGListTestOffsettingLayout.h */,
 				88144EF41D870EDC007C7F66 /* IGListTestOffsettingLayout.m */,
 				88144EF51D870EDC007C7F66 /* IGListTestSection.h */,
 				88144EF61D870EDC007C7F66 /* IGListTestSection.m */,
-				8285404A1DE40C6E00118B94 /* IGListTestHorizontalSection.h */,
-				8285404B1DE40C6E00118B94 /* IGListTestHorizontalSection.m */,
 				8240C7F61DC2F3FB00B3AAE7 /* IGListTestStoryboardSection.h */,
 				8240C7F71DC2F3FB00B3AAE7 /* IGListTestStoryboardSection.m */,
 				88144EF71D870EDC007C7F66 /* IGListTestUICollectionViewDataSource.h */,

diff --git a/Source/IGListStackedSectionController.m b/Source/IGListStackedSectionController.m
@@ -16,43 +16,13 @@
 
 #import "IGListSectionControllerInternal.h"
 
-@interface UICollectionViewCell (IGListStackedSectionController)
-@end
-@implementation UICollectionViewCell (IGListStackedSectionController)
-
-static void * kStackedSectionControllerKey = &kStackedSectionControllerKey;
-
-- (void)ig_setStackedSectionController:(id)stackedSectionController {
-    objc_setAssociatedObject(self, kStackedSectionControllerKey, stackedSectionController, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
-}
-
-- (id)ig_stackedSectionController {
-    return objc_getAssociatedObject(self, kStackedSectionControllerKey);
-}
-
-static void * kStackedSectionControllerIndexKey = &kStackedSectionControllerIndexKey;
-
-- (void)ig_setStackedSectionControllerIndex:(NSInteger)stackedSectionControllerIndex {
-    objc_setAssociatedObject(self, kStackedSectionControllerIndexKey, @(stackedSectionControllerIndex), OBJC_ASSOCIATION_ASSIGN);
-}
-
-- (NSInteger)ig_stackedSectionControllerIndex {
-    return [objc_getAssociatedObject(self, kStackedSectionControllerIndexKey) integerValue];
-}
-
-@end
-
 @implementation IGListStackedSectionController
 
 - (instancetype)initWithSectionControllers:(NSArray <IGListSectionController<IGListSectionType> *> *)sectionControllers {
     if (self = [super init]) {
         for (IGListSectionController<IGListSectionType> *sectionController in sectionControllers) {
             sectionController.collectionContext = self;
             sectionController.viewController = self.viewController;
-
-            if (self.supplementaryViewSource == nil) {
-                self.supplementaryViewSource = sectionController.supplementaryViewSource;
-            }
         }
 
         _visibleSectionControllers = [[NSCountedSet alloc] init];
@@ -123,6 +93,15 @@ - (NSIndexSet *)itemIndexesForSectionController:(IGListSectionController<IGListS
     return itemIndexes;
 }
 
+- (id<IGListSupplementaryViewSource>)supplementaryViewSource {
+    for (IGListSectionController *sectionController in self.sectionControllers) {
+        id<IGListSupplementaryViewSource> supplementaryViewSource = sectionController.supplementaryViewSource;
+        if (supplementaryViewSource != nil) {
+            return supplementaryViewSource;
+        }
+    }
+    return nil;
+}
 
 #pragma mark - IGListSectionType
 
@@ -305,9 +284,6 @@ - (void)listAdapter:(IGListAdapter *)listAdapter willDisplaySectionController:(I
     IGListSectionController<IGListSectionType> *childSectionController = [self sectionControllerForObjectIndex:index];
     const NSUInteger localIndex = [self localIndexForSectionController:childSectionController index:index];
 
-    [cell ig_setStackedSectionController:childSectionController];
-    [cell ig_setStackedSectionControllerIndex:localIndex];
-
     NSCountedSet *visibleSectionControllers = self.visibleSectionControllers;
     id<IGListDisplayDelegate> displayDelegate = [childSectionController displayDelegate];
 

diff --git a/Tests/IGListStackSectionControllerTests.m b/Tests/IGListStackSectionControllerTests.m
@@ -17,7 +17,13 @@
 #import "IGListDisplayHandler.h"
 #import "IGListStackedSectionControllerInternal.h"
 #import "IGListTestSection.h"
+#import "IGTestCell.h"
 #import "IGTestStackedDataSource.h"
+#import "IGTestStoryboardCell.h"
+#import "IGTestStoryboardViewController.h"
+#import "IGTestSupplementarySource.h"
+#import "IGTestSupplementarySource.h"
+#import "IGTestStoryboardSupplementarySource.h"
 
 static const CGRect kStackTestFrame = (CGRect){{0.0, 0.0}, {100.0, 100.0}};
 
@@ -37,9 +43,15 @@ - (void)setUp {
 
     self.window = [[UIWindow alloc] initWithFrame:kStackTestFrame];
 
-    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
-    self.collectionView = [[IGListCollectionView alloc] initWithFrame:kStackTestFrame collectionViewLayout:layout];
-    [self.window addSubview:self.collectionView];
+    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"IGTestStoryboard" bundle:[NSBundle bundleForClass:self.class]];
+    IGTestStoryboardViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"testVC"];
+    self.window.rootViewController = vc;
+    [self.window addSubview:vc.view];
+    [vc performSelectorOnMainThread:@selector(loadView) withObject:nil waitUntilDone:YES];
+    self.collectionView = vc.collectionView;
+
+    vc.view.frame = kStackTestFrame;
+    self.collectionView.frame = kStackTestFrame;
 
     self.dataSource = [[IGTestStackedDataSource alloc] init];
     self.adapter = [[IGListAdapter alloc] initWithUpdater:[IGListAdapterUpdater new] viewController:nil workingRangeSize:0];
@@ -431,4 +443,229 @@ - (void)test_whenPerformingItemUpdates_thatMutationsMapToSectionControllers {
     [self waitForExpectationsWithTimeout:15 handler:nil];
 }
 
+- (void)test_whenSelectingItems_thatChildSectionControllersSelected {
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@1 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                             ]];
+
+    [self.adapter collectionView:self.collectionView didSelectItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
+    [self.adapter collectionView:self.collectionView didSelectItemAtIndexPath:[NSIndexPath indexPathForItem:2 inSection:1]];
+    [self.adapter collectionView:self.collectionView didSelectItemAtIndexPath:[NSIndexPath indexPathForItem:1 inSection:2]];
+
+    IGListStackedSectionController *stack0 = [self.adapter sectionControllerForObject:self.dataSource.objects[0]];
+    IGListStackedSectionController *stack1 = [self.adapter sectionControllerForObject:self.dataSource.objects[1]];
+    IGListStackedSectionController *stack2 = [self.adapter sectionControllerForObject:self.dataSource.objects[2]];
+
+    XCTAssertTrue([stack0.sectionControllers[0] wasSelected]);
+    XCTAssertFalse([stack0.sectionControllers[1] wasSelected]);
+    XCTAssertFalse([stack0.sectionControllers[2] wasSelected]);
+    XCTAssertFalse([stack1.sectionControllers[0] wasSelected]);
+    XCTAssertTrue([stack1.sectionControllers[1] wasSelected]);
+    XCTAssertFalse([stack1.sectionControllers[2] wasSelected]);
+    XCTAssertFalse([stack2.sectionControllers[0] wasSelected]);
+    XCTAssertTrue([stack2.sectionControllers[1] wasSelected]);
+}
+
+- (void)test_whenUsingNibs_withStoryboards_thatCellsAreConfigured {
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@1, @"nib", @"storyboard"]],
+                             ]];
+
+    UICollectionViewCell *cell0 = [self.collectionView cellForItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
+    IGTestCell *cell1 = (IGTestCell *)[self.collectionView cellForItemAtIndexPath:[NSIndexPath indexPathForItem:1 inSection:0]];
+    IGTestStoryboardCell *cell2 = (IGTestStoryboardCell *)[self.collectionView cellForItemAtIndexPath:[NSIndexPath indexPathForItem:2 inSection:0]];
+
+    XCTAssertEqualObjects(cell0.class, [UICollectionViewCell class]);
+    XCTAssertEqualObjects(cell1.class, [IGTestCell class]);
+    XCTAssertEqualObjects(cell2.class, [IGTestStoryboardCell class]);
+
+    XCTAssertEqualObjects(cell1.label.text, @"nib");
+    XCTAssertEqualObjects(cell2.label.text, @"storyboard");
+}
+
+- (void)test_whenForwardingDidScrollEvent_thatChildSectionControllersReceiveEvent {
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                             ]];
+
+    id mockScrollDelegate = [OCMockObject mockForProtocol:@protocol(IGListScrollDelegate)];
+
+    IGListStackedSectionController *stack0 = [self.adapter sectionControllerForObject:self.dataSource.objects[0]];
+    IGListStackedSectionController *stack1 = [self.adapter sectionControllerForObject:self.dataSource.objects[1]];
+
+    stack0.scrollDelegate = mockScrollDelegate;
+    stack1.scrollDelegate = mockScrollDelegate;
+
+    [[mockScrollDelegate expect] listAdapter:self.adapter didScrollSectionController:stack0];
+    [[mockScrollDelegate expect] listAdapter:self.adapter didScrollSectionController:stack1];
+
+    [self.adapter scrollViewDidScroll:self.collectionView];
+
+    [mockScrollDelegate verify];
+}
+
+- (void)test_whenForwardingWillBeginDraggingEvent_thatChildSectionControllersReceiveEvent {
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                             ]];
+
+    id mockScrollDelegate = [OCMockObject mockForProtocol:@protocol(IGListScrollDelegate)];
+
+    IGListStackedSectionController *stack0 = [self.adapter sectionControllerForObject:self.dataSource.objects[0]];
+    IGListStackedSectionController *stack1 = [self.adapter sectionControllerForObject:self.dataSource.objects[1]];
+
+    stack0.scrollDelegate = mockScrollDelegate;
+    stack1.scrollDelegate = mockScrollDelegate;
+
+    [[mockScrollDelegate expect] listAdapter:self.adapter willBeginDraggingSectionController:stack0];
+    [[mockScrollDelegate expect] listAdapter:self.adapter willBeginDraggingSectionController:stack1];
+
+    [self.adapter scrollViewWillBeginDragging:self.collectionView];
+
+    [mockScrollDelegate verify];
+}
+
+- (void)test_whenForwardingDidEndDraggingEvent_thatChildSectionControllersReceiveEvent {
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                             ]];
+
+    id mockScrollDelegate = [OCMockObject mockForProtocol:@protocol(IGListScrollDelegate)];
+
+    IGListStackedSectionController *stack0 = [self.adapter sectionControllerForObject:self.dataSource.objects[0]];
+    IGListStackedSectionController *stack1 = [self.adapter sectionControllerForObject:self.dataSource.objects[1]];
+
+    stack0.scrollDelegate = mockScrollDelegate;
+    stack1.scrollDelegate = mockScrollDelegate;
+
+    [[mockScrollDelegate expect] listAdapter:self.adapter didEndDraggingSectionController:stack0 willDecelerate:NO];
+    [[mockScrollDelegate expect] listAdapter:self.adapter didEndDraggingSectionController:stack1 willDecelerate:NO];
+
+    [self.adapter scrollViewDidEndDragging:self.collectionView willDecelerate:NO];
+
+    [mockScrollDelegate verify];
+}
+
+- (void)test_whenUsingSupplementary_withCode_thatSupplementaryViewExists {
+    // updater that uses reloadData so we can rebuild all views/sizes
+    IGListAdapter *adapter = [[IGListAdapter alloc] initWithUpdater:[IGListReloadDataUpdater new] viewController:nil workingRangeSize:0];
+
+    self.dataSource.objects = @[
+                                [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                                [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                                ];
+
+    adapter.collectionView = self.collectionView;
+    adapter.dataSource = self.dataSource;
+    [self.collectionView layoutIfNeeded];
+
+    IGListStackedSectionController *stack = [adapter sectionControllerForObject:self.dataSource.objects[1]];
+    IGListTestSection *section = stack.sectionControllers.lastObject;
+
+    IGTestSupplementarySource *supplementarySource = [IGTestSupplementarySource new];
+    // the stack acts as the collection context. manually assign it.
+    supplementarySource.collectionContext = stack;
+    // however the actual section controller the supplementary serves is a child of the stack
+    supplementarySource.sectionController = section;
+    supplementarySource.supportedElementKinds = @[UICollectionElementKindSectionFooter];
+
+    section.supplementaryViewSource = supplementarySource;
+
+    [adapter performUpdatesAnimated:NO completion:nil];
+
+    XCTAssertNotNil([self.collectionView supplementaryViewForElementKind:UICollectionElementKindSectionFooter
+                                                             atIndexPath:[NSIndexPath indexPathForItem:0 inSection:1]]);
+    XCTAssertNotNil(supplementarySource);
+}
+
+- (void)test_whenUsingSupplementary_withNib_thatSupplementaryViewExists {
+    // updater that uses reloadData so we can rebuild all views/sizes
+    IGListAdapter *adapter = [[IGListAdapter alloc] initWithUpdater:[IGListReloadDataUpdater new] viewController:nil workingRangeSize:0];
+
+    self.dataSource.objects = @[
+                                [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                                [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                                ];
+
+    adapter.collectionView = self.collectionView;
+    adapter.dataSource = self.dataSource;
+    [self.collectionView layoutIfNeeded];
+
+    IGListStackedSectionController *stack = [adapter sectionControllerForObject:self.dataSource.objects[1]];
+    IGListTestSection *section = stack.sectionControllers.lastObject;
+
+    IGTestSupplementarySource *supplementarySource = [IGTestSupplementarySource new];
+    // the stack acts as the collection context. manually assign it.
+    supplementarySource.collectionContext = stack;
+    // however the actual section controller the supplementary serves is a child of the stack
+    supplementarySource.sectionController = section;
+    supplementarySource.supportedElementKinds = @[UICollectionElementKindSectionFooter];
+    supplementarySource.dequeueFromNib = YES;
+
+    section.supplementaryViewSource = supplementarySource;
+
+    [adapter performUpdatesAnimated:NO completion:nil];
+
+    XCTAssertNotNil([self.collectionView supplementaryViewForElementKind:UICollectionElementKindSectionFooter
+                                                             atIndexPath:[NSIndexPath indexPathForItem:0 inSection:1]]);
+    XCTAssertNotNil(supplementarySource);
+}
+
+- (void)test_whenUsingSupplementary_withStoryboard_thatSupplementaryViewExists {
+    // updater that uses reloadData so we can rebuild all views/sizes
+    IGListAdapter *adapter = [[IGListAdapter alloc] initWithUpdater:[IGListReloadDataUpdater new] viewController:nil workingRangeSize:0];
+
+    self.dataSource.objects = @[
+                                [[IGTestObject alloc] initWithKey:@0 value:@[@1, @2, @3]],
+                                [[IGTestObject alloc] initWithKey:@2 value:@[@1, @1]]
+                                ];
+
+    adapter.collectionView = self.collectionView;
+    adapter.dataSource = self.dataSource;
+    [self.collectionView layoutIfNeeded];
+
+    IGListStackedSectionController *stack = [adapter sectionControllerForObject:self.dataSource.objects[1]];
+    IGListTestSection *section = stack.sectionControllers.lastObject;
+
+    IGTestStoryboardSupplementarySource *supplementarySource = [IGTestStoryboardSupplementarySource new];
+    // the stack acts as the collection context. manually assign it.
+    supplementarySource.collectionContext = stack;
+    // however the actual section controller the supplementary serves is a child of the stack
+    supplementarySource.sectionController = section;
+
+    // the "section header" property of the parent collection view must be checked
+    supplementarySource.supportedElementKinds = @[UICollectionElementKindSectionHeader];
+
+    section.supplementaryViewSource = supplementarySource;
+
+    [adapter performUpdatesAnimated:NO completion:nil];
+
+    XCTAssertNotNil([self.collectionView supplementaryViewForElementKind:UICollectionElementKindSectionHeader
+                                                             atIndexPath:[NSIndexPath indexPathForItem:0 inSection:1]]);
+    XCTAssertNotNil(supplementarySource);
+}
+
+- (void)test_whenScrollingFromChildSectionController_thatScrollsToCorrectPosition {
+    // pad with enough items that we can freely scroll to the middle without accounting for content size
+    [self setupWithObjects:@[
+                             [[IGTestObject alloc] initWithKey:@0 value:@[@4, @5, @6]],
+                             [[IGTestObject alloc] initWithKey:@1 value:@[@1, @2, @3]],
+                             [[IGTestObject alloc] initWithKey:@2 value:@[@4, @5, @6]]
+                             ]];
+
+    IGListStackedSectionController *stack = [self.adapter sectionControllerForObject:self.dataSource.objects[1]];
+    IGListTestSection *section = stack.sectionControllers[1];
+
+    [section.collectionContext scrollToSectionController:section atIndex:1 scrollPosition:UICollectionViewScrollPositionTop animated:NO];
+
+    // IGListTestSection cells are 100x10
+    XCTAssertEqual(self.collectionView.contentOffset.x, 0);
+    XCTAssertEqual(self.collectionView.contentOffset.y, 170);
+}
+
 @end