AirBnB's MagazineLayout implementation -> dynamically resizing cells in MenuViewController, TODO: test resizing on real device, simulator delays resizing until after scrolling (possibly a bug)

AvH Plan/MenuViewController.swift

@@ -7,21 +7,42 @@
 //
 
 import UIKit
+import MagazineLayout
 
-class MenuViewController : UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
+class MenuViewController : UIViewController, UICollectionViewDataSource, UICollectionViewDelegateMagazineLayout {
     
-    let reuseIdentifier = "cell"
-    @IBOutlet weak var collectionView: UICollectionView!
     var items = [String]()
     private let refreshControl = UIRefreshControl()
     let df = DataFetcher()
+    @IBOutlet weak var toolbar: UINavigationBar!
+    let layout = MagazineLayout()
+    var collectionView: UICollectionView
+    let identifier = "menu_cell"
+    
+    required init?(coder decoder: NSCoder) {
+        collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
+        super.init(coder: decoder)
+    }
     
     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
+        
+        view.addSubview(collectionView)
+        collectionView.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
+            collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
+            collectionView.topAnchor.constraint(equalTo: self.toolbar.bottomAnchor),
+            collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
+        ])
+        collectionView.register(UINib(nibName: "MenuViewCell", bundle: nil), forCellWithReuseIdentifier: identifier)
+        collectionView.dataSource = self
+        collectionView.delegate = self
+        
         if #available(iOS 10.0, *) {
             collectionView.refreshControl = refreshControl
         } else {
-            collectionView.addSubview(refreshControl)
+            collectionView.addSubview(refreshControl) // likely unnecessary
         }
         refreshControl.addTarget(self, action: #selector(objDoAsync(_:)), for: .valueChanged)
         refreshControl.tintColor = UIColor(red: 0.39, green: 0.71, blue: 0.96, alpha: 1.0)
@@ -47,23 +68,55 @@ class MenuViewController : UIViewController, UICollectionViewDataSource, UIColle
     func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
         return self.items.count
     }
-    
+
     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
-        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MenuViewCell
+        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath as IndexPath) as! MenuViewCell
         if self.items.count != 0 {
             cell.content.text = self.items[indexPath.item]
         }
-        
+
         cell.backgroundColor = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
         return cell
     }
+
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
+        print("You selected cell#\(indexPath.item)!")
+    }
     
-        func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
-            print("You selected cell#\(indexPath.item)!")
-        }
+    // generated stubs filled with return values
     
-    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
-        return CGSize(width: view.frame.size.width, height: 64)
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeModeForItemAt indexPath: IndexPath) -> MagazineLayoutItemSizeMode {
+        let widthMode = MagazineLayoutItemWidthMode.fullWidth(respectsHorizontalInsets: true)
+        let heightMode = MagazineLayoutItemHeightMode.dynamic
+        return MagazineLayoutItemSizeMode(widthMode: widthMode, heightMode: heightMode)
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, visibilityModeForHeaderInSectionAtIndex index: Int) -> MagazineLayoutHeaderVisibilityMode {
+        return .hidden
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, visibilityModeForFooterInSectionAtIndex index: Int) -> MagazineLayoutFooterVisibilityMode {
+        return .hidden
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, visibilityModeForBackgroundInSectionAtIndex index: Int) -> MagazineLayoutBackgroundVisibilityMode {
+        return .hidden
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, horizontalSpacingForItemsInSectionAtIndex index: Int) -> CGFloat {
+        return 0
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, verticalSpacingForElementsInSectionAtIndex index: Int) -> CGFloat {
+        return 1
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetsForSectionAtIndex index: Int) -> UIEdgeInsets {
+        return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetsForItemsInSectionAtIndex index: Int) -> UIEdgeInsets {
+        return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
     }
 }