V1.7.0 (#150)

- Add support for setting scrollPosition through binding
- Improve function builders, support for unlimited number of static views, support for arrays
- Improve default self-sizing settings
- Support for automatic keyboard avoidance

Author: apptekstudios

.github/FUNDING.yml

@@ -9,4 +9,5 @@
 #liberapay: # Replace with a single Liberapay username
 #issuehunt: # Replace with a single IssueHunt username
 #otechie: # Replace with a single Otechie username
+github: apptekstudios
 custom: ['https://www.buymeacoffee.com/tobeasbrennan'] # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

.swiftformat

@@ -20,6 +20,7 @@
 --fractiongrouping disabled
 --ifdef outdent
 --importgrouping testable-top
---stripunusedargs closure-only
 --wraparguments before-first
 --wrapcollections after-first
+
+--disable unusedArguments

ASCollectionView-SwiftUI.podspec

@@ -1,7 +1,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'ASCollectionView-SwiftUI'
-  s.version          = '1.6.3'
+  s.version          = '1.7.0'
   s.summary          = 'A SwiftUI collection view with support for custom layouts, preloading, and more. '
 
   s.description      = <<-DESC

Demo/ASCollectionViewDemo/Screens/AppStore/AppStoreScreen.swift

@@ -61,8 +61,9 @@ struct AppStoreScreen: View
 	{
 		ASCollectionView(sections: self.sections)
 			.layout(self.layout)
+			.contentInsets(.init(top: 10, left: 0, bottom: 10, right: 0))
 			.shouldAttemptToMaintainScrollPositionOnOrientationChange(maintainPosition: false)
-			.navigationBarTitle("Apps", displayMode: .large)
+			.navigationBarTitle("Apps", displayMode: .inline)
 			.edgesIgnoringSafeArea(.all)
 	}
 
@@ -138,6 +139,8 @@ extension AppStoreScreen
 					section.interGroupSpacing = 20
 					section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 20, bottom: 0, trailing: 20)
 					section.orthogonalScrollingBehavior = .groupPaging
+					section.visibleItemsInvalidationHandler = { _, _, _ in } // If this isn't defined, there is a bug in UICVCompositional Layout that will fail to update sizes of cells
+
 					return section
 				}
 			case 1:
@@ -175,6 +178,8 @@ extension AppStoreScreen
 					section.boundarySupplementaryItems = [header]
 					section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 20, bottom: 0, trailing: 20)
 					section.orthogonalScrollingBehavior = .groupPaging
+					section.visibleItemsInvalidationHandler = { _, _, _ in } // If this isn't defined, there is a bug in UICVCompositional Layout that will fail to update sizes of cells
+
 					return section
 				}
 			default:
@@ -212,6 +217,8 @@ extension AppStoreScreen
 					section.boundarySupplementaryItems = [header]
 					section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 20, bottom: 0, trailing: 20)
 					section.orthogonalScrollingBehavior = .groupPaging
+					section.visibleItemsInvalidationHandler = { _, _, _ in } // If this isn't defined, there is a bug in UICVCompositional Layout that will fail to update sizes of cells
+
 					return section
 				}
 			}

Demo/ASCollectionViewDemo/Screens/InstaFeed/PostView.swift

@@ -100,7 +100,7 @@ struct PostView: View
 				)
 			buttonBar
 			textContent
-			Spacer()
+			Spacer().layoutPriority(2)
 		}
 		.padding([.top, .bottom])
 	}

Demo/BuildTools/Package.resolved

@@ -108,11 +108,12 @@ public extension ASCollectionView
 		return this
 	}
 
-	/// Set an initial scroll position for the ASCollectionView
-	func initialScrollPosition(_ position: ASCollectionViewScrollPosition?) -> Self
+	/// Set a binding that will scroll the ASCollectionView when set. It will always return nil once the scroll is applied (use onScroll to read scroll position)
+	func scrollPositionSetter(_ binding: Binding<ASCollectionViewScrollPosition?>) -> Self
 	{
 		var this = self
-		this.initialScrollPosition = position
+		_ = binding.wrappedValue // Touch the binding so that SwiftUI will notify us of future updates
+		this.scrollPositionSetter = binding
 		return this
 	}
 

Sources/ASCollectionView/ASCollectionView+Modifiers.swift

@@ -81,15 +81,22 @@ public extension ASTableViewSection
 {
 	func sectionHeaderInsetGrouped<Content: View>(content: () -> Content?) -> Self
 	{
-		var section = self
-		let insetGroupedContent =
-			content()
-				.font(.headline)
-				.frame(maxWidth: .infinity, alignment: .leading)
-				.padding(EdgeInsets(top: 12, leading: 0, bottom: 6, trailing: 0))
+		if let content = content()
+		{
+			var section = self
+			let insetGroupedContent =
+				content
+					.font(.headline)
+					.frame(maxWidth: .infinity, alignment: .leading)
+					.padding(EdgeInsets(top: 12, leading: 0, bottom: 6, trailing: 0))
 
-		section.setHeaderView(insetGroupedContent)
-		return section
+			section.setHeaderView(insetGroupedContent)
+			return section
+		}
+		else
+		{
+			return self
+		}
 	}
 }
 

Sources/ASCollectionView/ASTableView+Modifiers.swift

@@ -7,117 +7,103 @@ import UIKit
 @available(iOS 13.0, *)
 class ASCollectionViewCell: UICollectionViewCell, ASDataSourceConfigurableCell
 {
-	var indexPath: IndexPath?
 	var itemID: ASCollectionViewItemUniqueID?
 	var hostingController: ASHostingControllerProtocol?
 	{
-		didSet
-		{
-			hostingController?.invalidateCellLayoutCallback = invalidateLayoutCallback
-			hostingController?.collectionViewScrollToCellCallback = scrollToCellCallback
-		}
+		get { _hostingController }
+		set { _hostingController = newValue; attachView() }
 	}
 
-	weak var collectionView: UICollectionView?
+	private var _hostingController: ASHostingControllerProtocol?
 
+	weak var collectionViewController: AS_CollectionViewController?
 	var selfSizingConfig: ASSelfSizingConfig = .init(selfSizeHorizontally: true, selfSizeVertically: true)
 
-	var invalidateLayoutCallback: ((_ animated: Bool) -> Void)?
-	var scrollToCellCallback: ((UICollectionView.ScrollPosition) -> Void)?
-
-	func willAppear(in vc: UIViewController)
+	private var hasAppeared: Bool = false // Needed due to the `self-sizing` cell used by UICV
+	func willAppear()
 	{
-		if hostingController?.viewController.parent != vc
-		{
-			hostingController?.viewController.removeFromParent()
-			hostingController.map { vc.addChild($0.viewController) }
-			attachView()
-			hostingController?.viewController.didMove(toParent: vc)
-		}
+		hasAppeared = true
+		attachView()
 	}
 
 	func didDisappear()
 	{
-		hostingController?.viewController.removeFromParent()
+		hasAppeared = false
+		detachViews()
 	}
 
 	private func attachView()
 	{
+		guard hasAppeared else { return }
 		guard let hcView = hostingController?.viewController.view else
 		{
 			detachViews()
 			return
 		}
 		if hcView.superview != contentView
 		{
+			hostingController.map { collectionViewController?.addChild($0.viewController) }
 			contentView.subviews.forEach { $0.removeFromSuperview() }
 			contentView.addSubview(hcView)
-			setNeedsLayout()
+			hcView.frame = contentView.bounds
+			hostingController?.viewController.didMove(toParent: collectionViewController)
 		}
 	}
 
 	private func detachViews()
 	{
+		hostingController?.viewController.willMove(toParent: nil)
 		contentView.subviews.forEach { $0.removeFromSuperview() }
+		hostingController?.viewController.removeFromParent()
 	}
 
-	var shouldSkipNextRefresh: Bool = true
-
 	override func prepareForReuse()
 	{
-		indexPath = nil
 		itemID = nil
 		isSelected = false
-		hostingController = nil
-		shouldSkipNextRefresh = true
+		alpha = 1.0
+		_hostingController = nil
 	}
 
 	override func layoutSubviews()
 	{
 		super.layoutSubviews()
 
-		attachView()
-
 		if hostingController?.viewController.view.frame != contentView.bounds
 		{
-			UIView.performWithoutAnimation {
-				hostingController?.viewController.view.frame = contentView.bounds
-				hostingController?.viewController.view.setNeedsLayout()
-				hostingController?.viewController.view.layoutIfNeeded()
-			}
+			hostingController?.viewController.view.frame = contentView.bounds
+			hostingController?.viewController.view.setNeedsLayout()
 		}
+		hostingController?.viewController.view.layoutIfNeeded()
 	}
 
-	override func systemLayoutSizeFitting(_ targetSize: CGSize) -> CGSize
+	override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize
 	{
-		guard let hc = hostingController else
+		guard let hostingController = hostingController else { return CGSize(width: 1, height: 1) }
+
+		let selfSizeHorizontal = selfSizingConfig.selfSizeHorizontally ?? (horizontalFittingPriority != .required)
+		let selfSizeVertical = selfSizingConfig.selfSizeVertically ?? (verticalFittingPriority != .required)
+
+		guard selfSizeVertical || selfSizeHorizontal else
 		{
-			return CGSize(width: 1, height: 1)
-		} // Can't return .zero as UICollectionViewLayout will crash
+			return targetSize
+		}
 
-		let size = hc.sizeThatFits(
+		// We need to calculate a size for self-sizing. Layout the view to get swiftUI to update its state
+		hostingController.viewController.view.setNeedsLayout()
+		hostingController.viewController.view.layoutIfNeeded()
+		let size = hostingController.sizeThatFits(
 			in: targetSize,
 			maxSize: maxSizeForSelfSizing,
-			selfSizeHorizontal: selfSizingConfig.selfSizeHorizontally,
-			selfSizeVertical: selfSizingConfig.selfSizeVertically)
+			selfSizeHorizontal: selfSizeHorizontal,
+			selfSizeVertical: selfSizeVertical)
 		return size
 	}
 
-	override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize
-	{
-		systemLayoutSizeFitting(targetSize)
-	}
-
-	override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes
-	{
-		layoutAttributes.size = systemLayoutSizeFitting(layoutAttributes.size)
-		return layoutAttributes
-	}
-
 	var maxSizeForSelfSizing: ASOptionalSize
 	{
 		ASOptionalSize(
-			width: selfSizingConfig.canExceedCollectionWidth ? nil : collectionView.map { $0.contentSize.width - 0.001 },
-			height: selfSizingConfig.canExceedCollectionHeight ? nil : collectionView.map { $0.contentSize.height - 0.001 })
+			width: selfSizingConfig.canExceedCollectionWidth ? nil : collectionViewController.map { $0.collectionView.contentSize.width - 0.001 },
+			height: selfSizingConfig.canExceedCollectionHeight ? nil : collectionViewController.map { $0.collectionView.contentSize.height - 0.001 })
 	}
 }

Sources/ASCollectionView/Cells/ASCollectionViewCell.swift

@@ -16,9 +16,8 @@ class ASCollectionViewDecoration<Content: Decoration>: ASCollectionViewSupplemen
 	override init(frame: CGRect)
 	{
 		super.init(frame: frame)
-		let view = Content()
-		hostingController = ASHostingController(view)
-		willAppear(in: nil)
+		hostingController = ASHostingController(Content())
+		willAppear()
 	}
 
 	required init?(coder: NSCoder)