From eddc2f6b0841e0f1bd609e5cfca5078806f9759e Mon Sep 17 00:00:00 2001
From: Amir Khorsandi <amir.khorsandi@wetransfer.com>
Date: Sun, 7 Nov 2021 12:13:33 +0100
Subject: [PATCH] Compare data using Equatable if it conforms to

---
 .../PagingCollectionViewController.swift      | 21 +++++++++++++++++--
 .../xcschemes/PagingLayoutSamples.xcscheme    |  2 +-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/Lib/SwiftUI/PagingCollectionViewController.swift b/Lib/SwiftUI/PagingCollectionViewController.swift
index 5ad46ef..0420aff 100644
--- a/Lib/SwiftUI/PagingCollectionViewController.swift
+++ b/Lib/SwiftUI/PagingCollectionViewController.swift
@@ -57,9 +57,16 @@ public class PagingCollectionViewController<ValueType: Identifiable, PageContent
     // MARK: Internal functions
 
     func update(list: [ValueType], currentIndex: Int?) {
-        let oldIds = self.list.map(\.id)
+        var needsUpdate = false
+        
+        if let self = self as? PagingCollectionViewControllerEquatableList {
+            needsUpdate = !self.isListSame(as: list)
+        } else {
+            let oldIds = self.list.map(\.id)
+            needsUpdate = list.map(\.id) != oldIds
+        }
         self.list = list
-        if list.map(\.id) != oldIds {
+        if needsUpdate {
             collectionView?.reloadData()
             layout.invalidateLayoutInBatchUpdate(invalidateOffset: true)
         }
@@ -142,6 +149,16 @@ public class PagingCollectionViewController<ValueType: Identifiable, PageContent
 
 }
 
+private protocol PagingCollectionViewControllerEquatableList {
+    func isListSame<T>(as list: [T]) -> Bool
+}
+
+@available(iOS 13.0, *)
+extension PagingCollectionViewController: PagingCollectionViewControllerEquatableList where ValueType: Equatable {
+    func isListSame<T>(as list: [T]) -> Bool {
+        self.list == (list as? [ValueType])
+    }
+}
 
 @available(iOS 13.0, *)
 private extension UICollectionView {
diff --git a/Samples/PagingLayoutSamples.xcodeproj/xcshareddata/xcschemes/PagingLayoutSamples.xcscheme b/Samples/PagingLayoutSamples.xcodeproj/xcshareddata/xcschemes/PagingLayoutSamples.xcscheme
index 7b639a9..2d6c665 100644
--- a/Samples/PagingLayoutSamples.xcodeproj/xcshareddata/xcschemes/PagingLayoutSamples.xcscheme
+++ b/Samples/PagingLayoutSamples.xcodeproj/xcshareddata/xcschemes/PagingLayoutSamples.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1220"
+   LastUpgradeVersion = "1310"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"