From 03abdd3a9130829761145baceb93051e2970f27d Mon Sep 17 00:00:00 2001
From: "Pfeil, Scott Robert" <scott.pfeil3@verizonwireless.com>
Date: Wed, 22 Apr 2020 21:03:13 -0400
Subject: [PATCH] update collection for sizing properly

---
 MVMCoreUI/BaseClasses/CollectionView.swift          | 13 +++++++++++++
 .../ProgrammaticCollectionViewController.swift      |  4 ++--
 .../ThreeLayerCollectionViewController.swift        |  6 +++++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/MVMCoreUI/BaseClasses/CollectionView.swift b/MVMCoreUI/BaseClasses/CollectionView.swift
index a1a57376..4b034462 100644
--- a/MVMCoreUI/BaseClasses/CollectionView.swift
+++ b/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)
diff --git a/MVMCoreUI/BaseControllers/ProgrammaticCollectionViewController.swift b/MVMCoreUI/BaseControllers/ProgrammaticCollectionViewController.swift
index c70a3ef1..85e0f3a7 100644
--- a/MVMCoreUI/BaseControllers/ProgrammaticCollectionViewController.swift
+++ b/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
diff --git a/MVMCoreUI/BaseControllers/ThreeLayerCollectionViewController.swift b/MVMCoreUI/BaseControllers/ThreeLayerCollectionViewController.swift
index 29d401f0..880f5525 100644
--- a/MVMCoreUI/BaseControllers/ThreeLayerCollectionViewController.swift
+++ b/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