Fixing reuse and sizing issues.

MVMCoreUI/Atomic/Organisms/Carousel.swift

@@ -54,6 +54,32 @@ open class Carousel: View {
     
     private var size: CGFloat?
     
+    // Updates the model and index.
+    public func updateModelIndex() {
+        (model as? CarouselModel)?.index = pageIndex
+    }
+    
+    open override func layoutSubviews() {
+        super.layoutSubviews()
+        // Accounts for any collection size changes
+        DispatchQueue.main.async {
+            self.layoutCollection()
+        }
+    }
+    
+    /// Invalidates the layout and ensures we are paged to the correct cell.
+    open func layoutCollection() {
+        collectionView.collectionViewLayout.invalidateLayout()
+        showPeaking(false)
+
+        // Go to current cell. layoutIfNeeded is needed otherwise cellForItem returns nil for peaking logic. The dispatch is a sad way to ensure the collection view is ready to be scrolled.
+        DispatchQueue.main.async {
+            self.collectionView.scrollToItem(at: IndexPath(row: self.currentIndex, section: 0), at: self.itemAlignment, animated: false)
+            self.collectionView.layoutIfNeeded()
+            self.showPeaking(true)
+        }
+    }
+    
     // MARK: - MVMCoreViewProtocol
     open override func setupView() {
         super.setupView()
@@ -73,15 +99,12 @@ open class Carousel: View {
     open override func updateView(_ size: CGFloat) {
         super.updateView(size)
         self.size = size
-        collectionView.collectionViewLayout.invalidateLayout()
+        
-        showPeaking(false)
+        // Update cells and re-layout.
-
+        for cell in collectionView.visibleCells {
-        // Go to current cell. layoutIfNeeded is needed otherwise cellForItem returns nil for peaking logic. The dispatch is a sad way to ensure the collection view is ready to be scrolled.
+            (cell as? MVMCoreViewProtocol)?.updateView(size)
-        DispatchQueue.main.async {
-            self.collectionView.scrollToItem(at: IndexPath(row: self.currentIndex, section: 0), at: self.itemAlignment, animated: false)
-            self.collectionView.layoutIfNeeded()
-            self.showPeaking(true)
         }
+        layoutCollection()
     }
     
     // MARK: - MoleculeViewProtocol
@@ -108,6 +131,9 @@ open class Carousel: View {
         }
 
         setupPagingMolecule(carouselModel.pagingMolecule, delegateObject: delegateObject)
+        
+        pageIndex = carouselModel.index
+        pagingView?.setPage(carouselModel.index)
         collectionView.reloadData()
     }
     
@@ -197,6 +223,7 @@ open class Carousel: View {
                 }
                 let currentPage = pager.currentPage()
                 localSelf.pageIndex = currentPage
+                localSelf.updateModelIndex()
                 localSelf.goTo(localSelf.currentIndex, animated: !UIAccessibility.isVoiceOverRunning)
             })
         }
@@ -246,7 +273,7 @@ open class Carousel: View {
 
 extension Carousel: UICollectionViewDelegateFlowLayout {
     open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
-        let itemWidth = (size ?? collectionView.bounds.width) * CGFloat(itemWidthPercent)
+        let itemWidth = collectionView.bounds.width * CGFloat(itemWidthPercent)
         return CGSize(width: itemWidth, height: collectionView.bounds.height)
     }
     
@@ -280,19 +307,18 @@ extension Carousel: UIScrollViewDelegate {
     
     func goTo(_ index: Int, animated: Bool) {
         showPeaking(false)
-        setAccessiblity(collectionView.cellForItem(at: IndexPath(row: self.currentIndex, section: 0)), index: index)
+        setAccessiblity(collectionView.cellForItem(at: IndexPath(row: currentIndex, section: 0)), index: index)
-        self.currentIndex = index
+        currentIndex = index
-        self.collectionView.scrollToItem(at: IndexPath(row: self.currentIndex, section: 0), at: self.itemAlignment, animated: animated)
+        updateModelIndex()
-        if let cell = collectionView.cellForItem(at: IndexPath(row: self.currentIndex, section: 0)) {
+        collectionView.scrollToItem(at: IndexPath(row: currentIndex, section: 0), at: itemAlignment, animated: animated)
-            setAccessiblity(collectionView.cellForItem(at: IndexPath(row: self.currentIndex, section: 0)), index: index)
+        if let cell = collectionView.cellForItem(at: IndexPath(row: currentIndex, section: 0)) {
+            setAccessiblity(collectionView.cellForItem(at: IndexPath(row: currentIndex, section: 0)), index: index)
             UIAccessibility.post(notification: .layoutChanged, argument: cell)
         }
     }
     
     func handleUserOnBufferCell() {
-        guard loop else {
+        guard loop else { return }
-            return
-        }
 
         let lastPageIndex = numberOfPages + 1
         let goToIndex = {(index: Int) in
@@ -320,9 +346,11 @@ extension Carousel: UIScrollViewDelegate {
             let index = scrollView.contentOffset.x / (itemWidth + separatorWidth)
             let lastCellIndex = collectionView(collectionView, numberOfItemsInSection: 0) - 1
             if index < 1 {
-                self.currentIndex = 0
+                currentIndex = 0
+                updateModelIndex()
             } else if index > CGFloat(lastCellIndex - 1) {
-                self.currentIndex = lastCellIndex
+                currentIndex = lastCellIndex
+                updateModelIndex()
             }
         }
         
@@ -348,9 +376,7 @@ extension Carousel: UIScrollViewDelegate {
         targetContentOffset.pointee = scrollView.contentOffset
         
         // This is for setting up smooth custom paging. (Since UICollectionView only handles paging based on collection view size and not cell size).
-        guard let separatorWidth = (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)?.minimumLineSpacing else {
+        guard let separatorWidth = (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)?.minimumLineSpacing else { return }
-            return
-        }
         
         // We switch cards if we pass the velocity threshold or position threshold (currently 50%).
         let itemWidth = collectionView.bounds.width * CGFloat(itemWidthPercent)

MVMCoreUI/Atomic/Organisms/CarouselModel.swift

@@ -12,7 +12,7 @@ import UIKit
     public static var identifier: String = "carousel"
     public var backgroundColor: Color?
     public var molecules: [CarouselItemModel]
-
+    public var index: Int = 0
     public var spacing: Float?
     public var border: Bool?
     public var loop: Bool?
@@ -29,6 +29,7 @@ import UIKit
         case moleculeName
         case backgroundColor
         case molecules
+        case index
         case spacing
         case border
         case loop
@@ -40,15 +41,16 @@ import UIKit
 
    required public init(from decoder: Decoder) throws {
         let typeContainer = try decoder.container(keyedBy: CodingKeys.self)
-        self.molecules = try typeContainer.decode([CarouselItemModel].self, forKey: .molecules)
+        molecules = try typeContainer.decode([CarouselItemModel].self, forKey: .molecules)
-        self.backgroundColor = try typeContainer.decodeIfPresent(Color.self, forKey: .backgroundColor)
+        index = try typeContainer.decodeIfPresent(Int.self, forKey: .index) ?? 0
-        self.spacing = try typeContainer.decodeIfPresent(Float.self, forKey: .spacing)
+        backgroundColor = try typeContainer.decodeIfPresent(Color.self, forKey: .backgroundColor)
-        self.border = try typeContainer.decodeIfPresent(Bool.self, forKey: .border)
+        spacing = try typeContainer.decodeIfPresent(Float.self, forKey: .spacing)
-        self.loop = try typeContainer.decodeIfPresent(Bool.self, forKey: .loop)
+        border = try typeContainer.decodeIfPresent(Bool.self, forKey: .border)
-        self.height = try typeContainer.decodeIfPresent(Float.self, forKey: .height)
+        loop = try typeContainer.decodeIfPresent(Bool.self, forKey: .loop)
-        self.itemWidthPercent = try typeContainer.decodeIfPresent(Float.self, forKey: .itemWidthPercent)
+        height = try typeContainer.decodeIfPresent(Float.self, forKey: .height)
-        self.itemAlignment = try typeContainer.decodeIfPresent(UICollectionView.ScrollPosition.self, forKey: .itemAlignment)
+        itemWidthPercent = try typeContainer.decodeIfPresent(Float.self, forKey: .itemWidthPercent)
-        self.pagingMolecule = try typeContainer.decodeModelIfPresent(codingKey: .pagingMolecule)
+        itemAlignment = try typeContainer.decodeIfPresent(UICollectionView.ScrollPosition.self, forKey: .itemAlignment)
+        pagingMolecule = try typeContainer.decodeModelIfPresent(codingKey: .pagingMolecule)
    }
 
    public func encode(to encoder: Encoder) throws {

MVMCoreUI/BaseControllers/ThreeLayerTableViewController.swift

@@ -33,7 +33,7 @@ open class ThreeLayerTableViewController: ProgrammaticTableViewController {
             bottomView.updateView(width)
             showFooter(width)
         }
-        self.tableView?.reloadData()
+        tableView?.reloadData()
     }
     
     open override func handleNewData() {

MVMCoreUI/BaseControllers/ViewController.swift

@@ -278,7 +278,8 @@ import UIKit
             return
         }
         
-        if needsUpdateUI || screenSizeChanged() {
+        // First update should be explicit (hence the zero check)
+        if needsUpdateUI || (previousScreenSize != .zero && screenSizeChanged()) {
             updateViews()
             needsUpdateUI = false
         }