use DispatchQueue.main.async for collectionView.performBatchUpdates

Author: amirdew

Lib/CollectionViewPagingLayout.swift

@@ -222,9 +222,11 @@ public class CollectionViewPagingLayout: UICollectionViewLayout {
 
         // this is necessary when we want to set the current page without animation
         if !animated, page != currentPage, let collectionView = collectionView {
-            collectionView.performBatchUpdates({
-                collectionView.collectionViewLayout.invalidateLayout()
-            })
+            DispatchQueue.main.async {
+                collectionView.performBatchUpdates({
+                    collectionView.collectionViewLayout.invalidateLayout()
+                })
+            }
         }
     }
 

Samples/PagingLayoutSamples/Modules/LayoutDesigner/Code/LayoutDesignerCodePreviewViewModel.swift

@@ -137,9 +137,11 @@ struct LayoutDesignerCodePreviewViewModel {
             
             override func viewDidLayoutSubviews() {
                 super.viewDidLayoutSubviews()
-                collectionView?.performBatchUpdates({
-                    self.collectionView.collectionViewLayout.invalidateLayout()
-                })
+                DispatchQueue.main.async { [weak self] in
+                    self?.collectionView?.performBatchUpdates({ [weak self] in
+                        self?.collectionView?.collectionViewLayout.invalidateLayout()
+                    })
+                }
             }
             
             func collectionView(

Samples/PagingLayoutSamples/Modules/LayoutDesigner/Intro/LayoutDesignerIntroViewController.swift

@@ -36,9 +36,11 @@ class LayoutDesignerIntroViewController: UIViewController {
 
     override func viewDidLayoutSubviews() {
         super.viewDidLayoutSubviews()
-        collectionView?.performBatchUpdates({ [weak self] in
-            self?.collectionView.collectionViewLayout.invalidateLayout()
-        })
+        DispatchQueue.main.async { [weak self] in
+            self?.collectionView?.performBatchUpdates({ [weak self] in
+                self?.collectionView?.collectionViewLayout.invalidateLayout()
+            })
+        }
     }
 
 

Samples/PagingLayoutSamples/Modules/Shapes/ShapesViewController.swift

@@ -155,17 +155,20 @@ class ShapesViewController: UIViewController, NibBased, ViewModelBased {
         invalidateCollectionViewLayout()
     }
 
-    private func invalidateLayoutTypeCollectionViewLayout() { layoutTypeCollectionView?.collectionViewLayout.invalidateLayout()
-        layoutTypeCollectionView?.performBatchUpdates({
-            self.layoutTypeCollectionView.collectionViewLayout.invalidateLayout()
-        })
+    private func invalidateLayoutTypeCollectionViewLayout() {
+        DispatchQueue.main.async { [weak self] in
+            self?.layoutTypeCollectionView?.performBatchUpdates({ [weak self] in
+                self?.layoutTypeCollectionView?.collectionViewLayout.invalidateLayout()
+            })
+        }
     }
 
     private func invalidateCollectionViewLayout() {
-        collectionView?.collectionViewLayout.invalidateLayout()
-        collectionView?.performBatchUpdates({
-            self.collectionView.collectionViewLayout.invalidateLayout()
-        })
+        DispatchQueue.main.async { [weak self] in
+            self?.collectionView?.performBatchUpdates({ [weak self] in
+                self?.collectionView?.collectionViewLayout.invalidateLayout()
+            })
+        }
     }
 
     private func getPagingLayout(_ collectionView: UICollectionView) -> CollectionViewPagingLayout? {