CompositionalLayout support for SingleSectionCollectionViewAdapter (#124

)

Add section kit compositional layout support to the single section
collection view adapter

Example/Examples/Sources/Examples/ExampleList/ExampleListCoordinator+Presentable.swift

@@ -37,6 +37,14 @@ extension ExampleListCoordinator: Presentable {
                             presentable: VanillaSwiftExamples.EmojisCoordinator(navigationController: navigationController)
                         )
                     ),
+                    ExampleViewModel(
+                        name: "Activities",
+                        description: "An MVC example with compositional layout example using a SingleSectionCollectionViewAdapter that shows a single ListSectionController.",
+                        navigation: ExampleCoordinator(
+                            navigationController: navigationController,
+                            presentable: ActivitiesViewController()
+                        )
+                    ),
                     ExampleViewModel(
                         name: "Names",
                         description: "An MVVM-C architecture with compositional layout example by using a ListCompositionalLayoutCollectionViewAdapter that shows multiple ListCompositionalLayoutSectionController.",

Example/VanillaSwiftExamples/Sources/VanillaSwiftExamples/Activities/Activities.swift

@@ -0,0 +1,53 @@
+enum Activity: String, CaseIterable {
+    case workingOut
+
+    case practicingForASport
+
+    case playingASport
+
+    case swimmingLaps
+
+    case yogaClass
+
+    case running
+
+    case pilates
+
+    case homeRenovations
+
+    case meditating
+
+    case studyingForAnExam
+
+    case completingAnAssignment
+
+    case readingATextbook
+
+    case writingAnArticle
+
+    case editingAVideo
+
+    case learningANewSkill
+
+    case journalling
+
+    case joiningASocialGroup
+
+    case goingToARally
+
+    case attendingAnImprovClass
+
+    case goingToChurch
+
+    case spendingTimeWithFriends
+
+    var text: String {
+        rawValue
+            .replacingOccurrences(
+                of: "[A-Z]",
+                with: " $0",
+                options: .regularExpression
+            )
+            .capitalized
+    }
+}

Example/VanillaSwiftExamples/Sources/VanillaSwiftExamples/Activities/ActivitiesSectionController.swift

@@ -0,0 +1,43 @@
+import SectionKit
+import UIKit
+
+final class ActivitiesSectionController: ListSectionController<[String], String> {
+    override var layoutProvider: SectionLayoutProvider {
+        .compositionalLayout(
+            .init(
+                layoutSectionProvider: { _ in
+                    let layoutSize = NSCollectionLayoutSize(
+                        widthDimension: .fractionalWidth(1),
+                        heightDimension: .estimated(50)
+                    )
+
+                    let item = NSCollectionLayoutItem(layoutSize: layoutSize)
+                    let layout = NSCollectionLayoutSection(
+                        group: .vertical(
+                            layoutSize: layoutSize,
+                            subitem: item,
+                            count: 1
+                        )
+                    )
+                    return layout
+                }
+            )
+        )
+    }
+
+    override func items(for model: [String]) -> [String] {
+        model
+    }
+
+    override func cellForItem(
+        at indexPath: SectionIndexPath,
+        in context: CollectionViewContext
+    ) -> UICollectionViewCell {
+        let item = items[indexPath]
+        let cell: UICollectionViewListCell = context.dequeueReusableCell(for: indexPath)
+        var contentConfiguration = cell.defaultContentConfiguration()
+        contentConfiguration.text = item
+        cell.contentConfiguration = contentConfiguration
+        return cell
+    }
+}

Example/VanillaSwiftExamples/Sources/VanillaSwiftExamples/Activities/ActivitiesViewController.swift

@@ -0,0 +1,33 @@
+import UIKit
+import SectionKit
+
+public final class ActivitiesViewController: UIViewController {
+    private let collectionView: UICollectionView = {
+        let layout = SectionKitCompositionalLayout()
+        let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
+        collectionView.backgroundColor = .systemBackground
+        collectionView.alwaysBounceVertical = true
+        return collectionView
+    }()
+
+    private lazy var collectionViewAdapter = SingleSectionCollectionViewAdapter(
+        collectionView: collectionView,
+        viewController: self
+    )
+
+    override public func loadView() {
+        view = collectionView
+    }
+
+    override public func viewDidLoad() {
+        super.viewDidLoad()
+        title = "Activities"
+
+        let activities = Activity.allCases.map(\.text)
+        collectionViewAdapter.section = Section(
+            id: UUID(),
+            model: activities,
+            controller: ActivitiesSectionController(model: activities)
+        )
+    }
+}

SectionKit/Sources/CollectionViewAdapter/SingleSectionCollectionViewAdapter/SingleSectionCollectionViewAdapter.swift

@@ -45,6 +45,15 @@ open class SingleSectionCollectionViewAdapter: NSObject, CollectionViewAdapter {
             collectionView.dragDelegate = self
             collectionView.dropDelegate = self
         }
+        if #available(iOS 13.0, *),
+           let layout = collectionView.collectionViewLayout as? SectionKitCompositionalLayout {
+            layout.sections = { [weak self] in
+                guard let section = self?.collectionViewSection else {
+                    return []
+                }
+                return [section]
+            }
+        }
     }
 
     /**
@@ -86,6 +95,15 @@ open class SingleSectionCollectionViewAdapter: NSObject, CollectionViewAdapter {
             collectionView.dragDelegate = self
             collectionView.dropDelegate = self
         }
+        if #available(iOS 13.0, *),
+           let layout = collectionView.collectionViewLayout as? SectionKitCompositionalLayout {
+            layout.sections = { [weak self] in
+                guard let section = self?.collectionViewSection else {
+                    return []
+                }
+                return [section]
+            }
+        }
     }
 
     public let context: CollectionViewContext