remove unnecessary override of viewWillTransition and only load image

only once when view size has changed

ImageViewer/ViewController.swift

@@ -58,7 +58,6 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
     @IBOutlet var scrollingCollectionView: UICollectionView!
     var scrollPos: CGPoint!
     var hasSetContentOffset = false
-    var pageCount = 0
 
     var imageView = UIImageView()
     var mode = PageTurnMode.leftToRight
@@ -67,8 +66,7 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
     var currentPage: Int!
     var progress = ProgressIndices(v: 0, c: 0, i: 0)
     var currentPath: URL!
-
+    var lastLayoutSize: CGSize = .zero
-    var changedOrientation = false
 
     var leftTap: UITapGestureRecognizer!
     var rightTap: UITapGestureRecognizer!
@@ -673,9 +671,20 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
 
     override func viewDidLayoutSubviews() {
         super.viewDidLayoutSubviews()
+        guard view.bounds.size != lastLayoutSize else { return }
+        lastLayoutSize = UIScreen.main.bounds.size
         if scrollingCollectionView.isHidden == true || mode != .scroll
             || scrollingCollectionView.contentSize == .zero
         {
+            if metadata == nil { return }
+            imageLoader.loadImage(
+                archiveURL: getArchiveURL(progress.v),
+                filename: getImagePath(progress),
+                scaling: .scaleAspectFit,
+                screenSize: UIScreen.main.bounds.size
+            ) { image in
+                self.imageView.image = image
+            }
             return
         }
         if !hasSetContentOffset, scrollPos != nil {
@@ -686,8 +695,7 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
             }
             scrollingCollectionView.setContentOffset(offset, animated: false)
             hasSetContentOffset = true
-        } else if changedOrientation {
+        } else {
-            changedOrientation = false
             let screenSize = UIScreen.main.bounds.size
             var offset = scrollingCollectionView.contentOffset
             offset.y *= (screenSize.width / screenSize.height)
@@ -1330,24 +1338,6 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
         }
         return nil
     }
-
-    override func viewWillTransition(
-        to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator
-    ) {
-        super.viewWillTransition(to: size, with: coordinator)
-        if mode != .scroll {
-            imageLoader.loadImage(
-                archiveURL: getArchiveURL(progress.v),
-                filename: getImagePath(progress),
-                scaling: .scaleAspectFit,
-                screenSize: size
-            ) { image in
-                self.imageView.image = image
-            }
-        } else {
-            changedOrientation = true
-        }
-    }
 }
 
 func getGlobalState() -> GlobalState {