update collection for sizing properly

MVMCoreUI/BaseClasses/CollectionView.swift

@@ -10,6 +10,11 @@ import Foundation
 
 open class CollectionView: UICollectionView, MVMCoreViewProtocol {
     
+    /// A block that gets called on tableview frame changes
+    public var frameChangeAction: (() -> Void)?
+    
+    private var previousFrame = CGRect.zero
+    
     private var initialSetupPerformed = false
     
     private func initialSetup() {
@@ -29,6 +34,14 @@ open class CollectionView: UICollectionView, MVMCoreViewProtocol {
         initialSetup()
     }
     
+    open override func layoutSubviews() {
+        super.layoutSubviews()
+        if frame != previousFrame {
+            frameChangeAction?()
+        }
+        previousFrame = frame
+    }
+    
     public func updateView(_ size: CGFloat) {
         for cell in visibleCells {
             (cell as? MVMCoreViewProtocol)?.updateView(size)

MVMCoreUI/BaseControllers/ProgrammaticCollectionViewController.swift

@@ -11,7 +11,7 @@ import Foundation
 /// A base view controller with a collection view.
 @objc open class ProgrammaticCollectionViewController: ScrollingViewController {
     
-    public var collectionView: UICollectionView?
+    public var collectionView: CollectionView?
     public var topConstraint: NSLayoutConstraint?
     public var bottomConstraint: NSLayoutConstraint?
 
@@ -49,7 +49,7 @@ import Foundation
     }
 
     /// Creates the collection view.
-    open func createCollectionView() -> UICollectionView {
+    open func createCollectionView() -> CollectionView {
         let collection = CollectionView(frame: .zero, collectionViewLayout: createCollectionViewLayout())
         collection.dataSource = self
         collection.delegate = self

MVMCoreUI/BaseControllers/ThreeLayerCollectionViewController.swift

@@ -22,7 +22,7 @@ import Foundation
     
     /// Updates the padding for flexible space (header or footer)
     private func updateFlexibleSpace() {
-        guard false,let collectionView = collectionView else { return }
+        guard let collectionView = collectionView else { return }
 
         let minimumSpace: CGFloat = minimumFillSpace()
         var currentSpace: CGFloat = 0
@@ -126,6 +126,10 @@ import Foundation
     override open func viewDidLoad() {
         super.viewDidLoad()
         // Do any additional setup after loading the view.
+        
+        collectionView?.frameChangeAction = { [weak self] in
+            self?.invalidateCollectionLayout()
+        }
     }
     
     //MARK: - Spacing