Add support for headers/footers in ASTableView (apptekstudios#48)

Fix apptekstudios#9

Demo/ASCollectionViewDemo/Models/Post.swift

@@ -47,7 +47,25 @@ struct Post: Identifiable
 
 struct DataSource
 {
-	static func postsForSection(_ sectionID: Int, number: Int = 12) -> [Post]
+	static func postsForGridSection(_ sectionID: Int, number: Int = 12) -> [Post]
+	{
+		(0..<number).map
+			{ b -> Post in
+				let aspect: CGFloat = 1
+				return Post.randomPost(sectionID * 10_000 + b, aspectRatio: aspect, offset: b)
+		}
+	}
+
+	static func postsForInstaSection(_ sectionID: Int, number: Int = 12) -> [Post]
+	{
+		(0..<number).map
+			{ b -> Post in
+				let aspect: CGFloat = [0.75, 1.0, 1.5].randomElement() ?? 1
+				return Post.randomPost(sectionID * 10_000 + b, aspectRatio: aspect, offset: b)
+		}
+	}
+
+	static func postsForWaterfallSection(_ sectionID: Int, number: Int = 12) -> [Post]
 	{
 		(0..<number).map
 			{ b -> Post in

Demo/ASCollectionViewDemo/Screens/AdjustableLayout/AdjustableGridScreen.swift

@@ -17,7 +17,7 @@ struct AdjustableGridScreen: View
 	@ObservedObject var layoutState = LayoutState()
 	@State var showConfig: Bool = true
 	@State var animateChange: Bool = false
-	@State var data: [Post] = DataSource.postsForSection(1, number: 1000)
+	@State var data: [Post] = DataSource.postsForGridSection(1, number: 1000)
 
 	typealias SectionID = Int
 

Demo/ASCollectionViewDemo/Screens/InstaFeed/InstaFeedScreen.swift

@@ -6,7 +6,7 @@ import UIKit
 
 struct InstaFeedScreen: View
 {
-	@State var data: [[Post]] = (0...3).map { DataSource.postsForSection($0) }
+	@State var data: [[Post]] = (0...3).map { DataSource.postsForInstaSection($0) }
 
 	var sections: [ASTableViewSection<Int>]
 	{
@@ -37,11 +37,22 @@ struct InstaFeedScreen: View
 				return ASTableViewSection(
 					id: i,
 					data: sectionData,
-					estimatedItemSize: CGSize(width: 0, height: 500),
 					onCellEvent: onCellEventPosts)
 				{ item, _ in
 					PostView(post: item)
 				}
+				.tableViewSetEstimatedSizes(rowHeight: 500, headerHeight: 50) //Optional: Provide reasonable estimated heights for this section
+				.sectionHeader {
+					VStack(spacing: 0) {
+						HStack {
+							Text("Demo sticky header view")
+								.padding(EdgeInsets(top: 4, leading: 20, bottom: 4, trailing: 20))
+							Spacer()
+						}
+						Divider()
+					}
+					.background(Color(.secondarySystemBackground))
+				}
 			}
 		}
 	}
@@ -60,7 +71,7 @@ struct InstaFeedScreen: View
 	func loadMoreContent()
 	{
 		let a = data.count
-		data.append(DataSource.postsForSection(a))
+		data.append(DataSource.postsForInstaSection(a))
 	}
 
 	func onCellEventStories(_ event: CellEvent<Post>)

Demo/ASCollectionViewDemo/Screens/MagazineLayout/MagazineLayoutScreen.swift

@@ -9,7 +9,7 @@ struct MagazineLayoutScreen: View
 {
 	@State var data: [[Post]] = (0...5).map
 	{
-		DataSource.postsForSection($0, number: 10)
+		DataSource.postsForGridSection($0, number: 10)
 	}
 
 	var sections: [ASCollectionViewSection<Int>]

Demo/ASCollectionViewDemo/Screens/PhotoGrid/PhotoGridScreen.swift

@@ -6,7 +6,7 @@ import UIKit
 
 struct PhotoGridScreen: View
 {
-	@State var data: [Post] = DataSource.postsForSection(1, number: 1000)
+	@State var data: [Post] = DataSource.postsForGridSection(1, number: 1000)
 	@State var selectedItems: IndexSet = []
 
 	@Environment(\.editMode) private var editMode

Demo/ASCollectionViewDemo/Screens/Waterfall/WaterfallScreen.swift

@@ -8,7 +8,7 @@ import UIKit
 ///THIS IS A WORK IN PROGRESS
 struct WaterfallScreen: View
 {
-	@State var data: [Post] = DataSource.postsForSection(1, number: 1000)
+	@State var data: [Post] = DataSource.postsForWaterfallSection(1, number: 1000)
 	@State var selectedItems: [SectionID: IndexSet] = [:]
 	@State var columnMinSize: CGFloat = 150
 

Sources/ASCollectionView/ASCollectionViewSection.swift

@@ -33,7 +33,10 @@ public struct ASCollectionViewSection<SectionID: Hashable>: Hashable
 		dataSource.getUniqueItemIDs(withSectionID: id)
 	}
 
-	var estimatedItemSize: CGSize?
+	//Only relevant for ASTableView
+	var estimatedRowHeight: CGFloat?
+	var estimatedHeaderHeight: CGFloat?
+	var estimatedFooterHeight: CGFloat?
 
 	/**
 	 Initializes a  section with data
@@ -42,7 +45,6 @@ public struct ASCollectionViewSection<SectionID: Hashable>: Hashable
 	 	- id: The id for this section
 	 	- data: The data to display in the section. This initialiser expects data that conforms to 'Identifiable'
 	 	- dataID: The keypath to a hashable identifier of each data item
-	 	- estimatedItemSize: (Optional) Provide an estimated item size to aid in calculating the layout
 	 	- onCellEvent: Use this to respond to cell appearance/disappearance, and preloading events.
 	 - onDragDropEvent: Define this closure to enable drag/drop and respond to events (default is nil: drag/drop disabled)
 	 	- contentBuilder: A closure returning a SwiftUI view for the given data item
@@ -51,13 +53,11 @@ public struct ASCollectionViewSection<SectionID: Hashable>: Hashable
 		id: SectionID,
 		data: [Data],
 		dataID dataIDKeyPath: KeyPath<Data, DataID>,
-		estimatedItemSize: CGSize? = nil,
 		onCellEvent: OnCellEvent<Data>? = nil,
 		onDragDropEvent: OnDragDrop<Data>? = nil,
 		@ViewBuilder contentBuilder: @escaping ((Data, CellContext) -> Content))
 	{
 		self.id = id
-		self.estimatedItemSize = estimatedItemSize
 		dataSource = ASSectionDataSource<Data, DataID, Content>(
 			data: data,
 			dataIDKeyPath: dataIDKeyPath,
@@ -137,6 +137,15 @@ public extension ASCollectionViewSection
 		section.setSupplementaryView(content(), ofKind: kind)
 		return section
 	}
+
+	func tableViewSetEstimatedSizes(rowHeight: CGFloat? = nil, headerHeight: CGFloat? = nil, footerHeight: CGFloat? = nil) -> Self
+	{
+		var section = self
+		section.estimatedRowHeight = rowHeight
+		section.estimatedHeaderHeight = headerHeight
+		section.estimatedFooterHeight = footerHeight
+		return section
+	}
 }
 
 // MARK: STATIC CONTENT SECTION
@@ -189,19 +198,17 @@ public extension ASCollectionViewSection
 	 - Parameters:
 	 	- id: The id for this section
 	 	- data: The data to display in the section. This initialiser expects data that conforms to 'Identifiable'
-	 	- estimatedItemSize: (Optional) Provide an estimated item size to aid in calculating the layout
 	 	- onCellEvent: Use this to respond to cell appearance/disappearance, and preloading events.
 	 - onDragDropEvent: Define this closure to enable drag/drop and respond to events (default is nil: drag/drop disabled)
 	 	- contentBuilder: A closure returning a SwiftUI view for the given data item
 	 */
 	@inlinable init<Content: View, Data: Identifiable>(
 		id: SectionID,
 		data: [Data],
-		estimatedItemSize: CGSize? = nil,
 		onCellEvent: OnCellEvent<Data>? = nil,
 		onDragDropEvent: OnDragDrop<Data>? = nil,
 		@ViewBuilder contentBuilder: @escaping ((Data, CellContext) -> Content))
 	{
-		self.init(id: id, data: data, dataID: \.id, estimatedItemSize: estimatedItemSize, onCellEvent: onCellEvent, onDragDropEvent: onDragDropEvent, contentBuilder: contentBuilder)
+		self.init(id: id, data: data, dataID: \.id, onCellEvent: onCellEvent, onDragDropEvent: onDragDropEvent, contentBuilder: contentBuilder)
 	}
 }

Sources/ASCollectionView/ASTableView.swift

@@ -11,9 +11,9 @@ extension ASTableView where SectionID == Int
 	 - Parameters:
 	 - section: A single section (ASTableViewSection)
 	 */
-	public init(mode: UITableView.Style = .plain, selectedItems: Binding<IndexSet>? = nil, section: Section)
+	public init(style: UITableView.Style = .plain, selectedItems: Binding<IndexSet>? = nil, section: Section)
 	{
-		self.mode = mode
+		self.style = style
 		self.selectedItems = selectedItems.map
 		{ selectedItems in
 			Binding(
@@ -27,13 +27,13 @@ extension ASTableView where SectionID == Int
 	 Initializes a  table view with a single section.
 	 */
 	public init<Data, DataID: Hashable, Content: View>(
-		mode: UITableView.Style = .plain,
+		style: UITableView.Style = .plain,
 		data: [Data],
 		dataID dataIDKeyPath: KeyPath<Data, DataID>,
 		selectedItems: Binding<IndexSet>? = nil,
 		@ViewBuilder contentBuilder: @escaping ((Data, CellContext) -> Content))
 	{
-		self.mode = mode
+		self.style = style
 		let section = ASTableViewSection(
 			id: 0,
 			data: data,
@@ -53,7 +53,7 @@ extension ASTableView where SectionID == Int
 	 */
 	init(@ViewArrayBuilder staticContent: (() -> [AnyView])) //Clashing with above functions in Swift 5.1, therefore internal for time being
 	{
-		self.mode = .plain
+		self.style = .plain
 		self.sections = [
 			ASTableViewSection(id: 0, content: staticContent)
 		]
@@ -66,7 +66,7 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 {
 	public typealias Section = ASTableViewSection<SectionID>
 	public var sections: [Section]
-	public var mode: UITableView.Style
+	public var style: UITableView.Style
 	public var selectedItems: Binding<[SectionID: IndexSet]>?
 
 	@Environment(\.tableViewSeparatorsEnabled) private var separatorsEnabled
@@ -82,16 +82,16 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 	 - Parameters:
 	 - sections: An array of sections (ASTableViewSection)
 	 */
-	@inlinable public init(mode: UITableView.Style = .plain, selectedItems: Binding<[SectionID: IndexSet]>? = nil, sections: [Section])
+	@inlinable public init(style: UITableView.Style = .plain, selectedItems: Binding<[SectionID: IndexSet]>? = nil, sections: [Section])
 	{
-		self.mode = mode
+		self.style = style
 		self.selectedItems = selectedItems
 		self.sections = sections
 	}
 
-	@inlinable public init(mode: UITableView.Style = .plain, selectedItems: Binding<[SectionID: IndexSet]>? = nil, @SectionArrayBuilder <SectionID> sectionBuilder: () -> [Section])
+	@inlinable public init(style: UITableView.Style = .plain, selectedItems: Binding<[SectionID: IndexSet]>? = nil, @SectionArrayBuilder <SectionID> sectionBuilder: () -> [Section])
 	{
-		self.mode = mode
+		self.style = style
 		self.selectedItems = selectedItems
 		sections = sectionBuilder()
 	}
@@ -100,7 +100,7 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 	{
 		context.coordinator.parent = self
 
-		let tableViewController = UITableViewController(style: .plain)
+		let tableViewController = UITableViewController(style: style)
 		tableViewController.tableView.tableFooterView = UIView()
 		updateTableViewSettings(tableViewController.tableView)
 		context.coordinator.tableViewController = tableViewController
@@ -246,7 +246,7 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 
 		public func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat
 		{
-			parent.sections[indexPath.section].estimatedItemSize?.height ?? 50
+			parent.sections[indexPath.section].estimatedRowHeight ?? 50
 		}
 
 		public func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)
@@ -336,6 +336,58 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 				selectedItemsBinding.wrappedValue = selectedBySection
 			}
 		}
+
+		public func tableView(_ tableView: UITableView, estimatedHeightForHeaderInSection section: Int) -> CGFloat {
+			guard self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionHeader) != nil else {
+				return CGFloat.leastNormalMagnitude
+			}
+			return parent.sections[section].estimatedHeaderHeight ?? 50
+		}
+
+		public func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
+			guard self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionHeader) != nil else {
+				return CGFloat.leastNormalMagnitude
+			}
+			return UITableView.automaticDimension
+		}
+
+		public func tableView(_ tableView: UITableView, estimatedHeightForFooterInSection section: Int) -> CGFloat {
+			guard self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionFooter) != nil else {
+				return CGFloat.leastNormalMagnitude
+			}
+			return parent.sections[section].estimatedFooterHeight ?? 50
+		}
+
+		public func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
+			guard self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionFooter) != nil else {
+				return CGFloat.leastNormalMagnitude
+			}
+			return UITableView.automaticDimension
+		}
+
+		public func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
+			guard let reusableView = tableView.dequeueReusableHeaderFooterView(withIdentifier: self.supplementaryReuseID) as? ASTableViewSupplementaryView
+				else { return nil }
+			if let supplementaryView = self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionHeader)
+			{
+				reusableView.setupFor(
+					id: section,
+					view: supplementaryView)
+			}
+			return reusableView
+		}
+
+		public func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
+			guard let reusableView = tableView.dequeueReusableHeaderFooterView(withIdentifier: self.supplementaryReuseID) as? ASTableViewSupplementaryView
+				else { return nil }
+			if let supplementaryView = self.parent.sections[section].supplementary(ofKind: UICollectionView.elementKindSectionFooter)
+			{
+				reusableView.setupFor(
+					id: section,
+					view: supplementaryView)
+			}
+			return reusableView
+		}
 
 		public func scrollViewDidScroll(_ scrollView: UIScrollView)
 		{
@@ -360,3 +412,20 @@ public struct ASTableView<SectionID: Hashable>: UIViewControllerRepresentable
 		}
 	}
 }
+
+/*
+class ASTableViewDataSource<SectionIdentifierType, ItemIdentifierType>: UITableViewDiffableDataSource<SectionIdentifierType, ItemIdentifierType> where SectionIdentifierType : Hashable, ItemIdentifierType : Hashable {
+	public typealias HeaderFooterViewProvider = (_ sectionIndex: Int) -> UITableViewHeaderFooterView?
+
+	public var headerViewProvider: HeaderFooterViewProvider?
+	public var footerViewProvider: HeaderFooterViewProvider?
+
+	func headerView(forSection section: Int) -> UITableViewHeaderFooterView? {
+		headerViewProvider?(section)
+	}
+
+	func footerView(forSection section: Int) -> UITableViewHeaderFooterView? {
+		footerViewProvider?(section)
+	}
+}
+*/

Sources/ASCollectionView/ASTableViewCells.swift

@@ -88,7 +88,16 @@ class ASTableViewSupplementaryView: UITableViewHeaderFooterView
 	var hostingController: ASHostingControllerProtocol?
 
 	private(set) var id: Int?
-
+
+	override init(reuseIdentifier: String?) {
+		super.init(reuseIdentifier: reuseIdentifier)
+		backgroundView = UIView()
+	}
+
+	required init?(coder: NSCoder) {
+		fatalError("init(coder:) has not been implemented")
+	}
+
 	func setupFor<Content: View>(id: Int, view: Content?)
 	{
 		self.id = id
@@ -99,7 +108,7 @@ class ASTableViewSupplementaryView: UITableViewHeaderFooterView
 		else
 		{
 			hostingController = nil
-			subviews.forEach { $0.removeFromSuperview() }
+			contentView.subviews.forEach { $0.removeFromSuperview() }
 		}
 	}
 
@@ -115,7 +124,7 @@ class ASTableViewSupplementaryView: UITableViewHeaderFooterView
 		{
 			$0.viewController.removeFromParent()
 			vc?.addChild($0.viewController)
-			addSubview($0.viewController.view)
+			contentView.addSubview($0.viewController.view)
 
 			setNeedsLayout()
 
@@ -131,13 +140,13 @@ class ASTableViewSupplementaryView: UITableViewHeaderFooterView
 	override func prepareForReuse()
 	{
 		hostingController = nil
-		subviews.forEach { $0.removeFromSuperview() }
+		contentView.subviews.forEach { $0.removeFromSuperview() }
 	}
 
 	override func layoutSubviews()
 	{
 		super.layoutSubviews()
-		hostingController?.viewController.view.frame = bounds
+		hostingController?.viewController.view.frame = contentView.bounds
 	}
 
 	override func systemLayoutSizeFitting(_ targetSize: CGSize) -> CGSize