From ae339525047d0260d15483682ab81dff2c795614 Mon Sep 17 00:00:00 2001
From: Kyle Van Essen <k@squareup.com>
Date: Wed, 20 Sep 2023 16:42:24 -0700
Subject: [PATCH] Force layout before appear, to avoid animated updates (#505)

* Force layout of views before they appear, to avoid animated updates occurring when cells are recycled.
---
 CHANGELOG.md                                     |  1 +
 .../PresentationState.HeaderFooterState.swift    | 14 +++++++++-----
 .../PresentationState.ItemState.swift            | 16 ++++++++++------
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6772690..551a6469 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - Fixed a bug that resulted in header/footer views not properly updating, by fixing the underlying tracking of collection view supplementary views.
 - Fixed an issue where supplementary views (headers or footers) that contained a first responder would result in the view being duplicated when scrolled off-screen.
+- Fixed an issue where animations would occur when dequeuing / reusing cells. A layout is now forced without animation before presentation.
 
 ### Added
 
diff --git a/ListableUI/Sources/Internal/PresentationState/PresentationState.HeaderFooterState.swift b/ListableUI/Sources/Internal/PresentationState/PresentationState.HeaderFooterState.swift
index 49128916..e7ac5a68 100644
--- a/ListableUI/Sources/Internal/PresentationState/PresentationState.HeaderFooterState.swift
+++ b/ListableUI/Sources/Internal/PresentationState/PresentationState.HeaderFooterState.swift
@@ -175,11 +175,15 @@ extension PresentationState
                 HeaderFooterContentView<Content>(frame: frame)
             }
             
-            self.applyTo(
-                view: view,
-                for: .willDisplay,
-                with: .init(environment: environment)
-            )
+            UIView.performWithoutAnimation {
+                self.applyTo(
+                    view: view,
+                    for: .willDisplay,
+                    with: .init(environment: environment)
+                )
+                
+                view.layoutIfNeeded()
+            }
             
             return view
         }
diff --git a/ListableUI/Sources/Internal/PresentationState/PresentationState.ItemState.swift b/ListableUI/Sources/Internal/PresentationState/PresentationState.ItemState.swift
index 891687e7..e671419e 100644
--- a/ListableUI/Sources/Internal/PresentationState/PresentationState.ItemState.swift
+++ b/ListableUI/Sources/Internal/PresentationState/PresentationState.ItemState.swift
@@ -259,12 +259,16 @@ extension PresentationState
             
             let itemState = ListableUI.ItemState(cell: cell, isReordering: false)
             
-            self.applyTo(
-                cell: cell,
-                itemState: itemState,
-                reason: .willDisplay,
-                environment: environment
-            )
+            UIView.performWithoutAnimation {
+                self.applyTo(
+                    cell: cell,
+                    itemState: itemState,
+                    reason: .willDisplay,
+                    environment: environment
+                )
+                
+                cell.layoutIfNeeded()
+            }
             
             return cell
         }