From 0e636bf937f8867945aac9a569f052586503cf3a Mon Sep 17 00:00:00 2001
From: "Simon (darkside) Jackson" <darkside@zenithmoon.com>
Date: Mon, 28 Sep 2020 14:00:09 +0100
Subject: [PATCH] Fixed a conflict when using the ScrollConflictManager in
 child content of a HSS or VSS

---
 Runtime/Scripts/Layout/HorizontalScrollSnap.cs | 12 ++++++++++++
 Runtime/Scripts/Layout/VerticalScrollSnap.cs   | 12 ++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/Runtime/Scripts/Layout/HorizontalScrollSnap.cs b/Runtime/Scripts/Layout/HorizontalScrollSnap.cs
index f533370..1baacfd 100644
--- a/Runtime/Scripts/Layout/HorizontalScrollSnap.cs
+++ b/Runtime/Scripts/Layout/HorizontalScrollSnap.cs
@@ -12,6 +12,8 @@ namespace UnityEngine.UI.Extensions
     [AddComponentMenu("Layout/Extensions/Horizontal Scroll Snap")]
     public class HorizontalScrollSnap : ScrollSnapBase
     {
+        private bool updated = true;
+
         void Start()
         {
             _isVertical = false;
@@ -23,6 +25,8 @@ namespace UnityEngine.UI.Extensions
 
         void Update()
         {
+            updated = false;
+
             if (!_lerp && _scroll_rect.velocity == Vector2.zero)
             {
                 if (!_settled && !_pointerDown)
@@ -243,6 +247,14 @@ namespace UnityEngine.UI.Extensions
         /// <param name="eventData"></param>
         public override void OnEndDrag(PointerEventData eventData)
         {
+            if (updated)
+            {
+                return;
+            }
+
+            // to prevent double dragging, only act on EndDrag once per frame
+            updated = true;
+
             _pointerDown = false;
 
             if (_scroll_rect.horizontal)
diff --git a/Runtime/Scripts/Layout/VerticalScrollSnap.cs b/Runtime/Scripts/Layout/VerticalScrollSnap.cs
index a8228d8..e0c5bb0 100644
--- a/Runtime/Scripts/Layout/VerticalScrollSnap.cs
+++ b/Runtime/Scripts/Layout/VerticalScrollSnap.cs
@@ -12,6 +12,8 @@ namespace UnityEngine.UI.Extensions
     [AddComponentMenu("Layout/Extensions/Vertical Scroll Snap")]
     public class VerticalScrollSnap : ScrollSnapBase
     {
+        private bool updated = true;
+
         void Start()
         {
             _isVertical = true;
@@ -23,6 +25,8 @@ namespace UnityEngine.UI.Extensions
 
         void Update()
         {
+            updated = false;
+
             if (!_lerp && _scroll_rect.velocity == Vector2.zero)
             {
                 if (!_settled && !_pointerDown)
@@ -236,6 +240,14 @@ namespace UnityEngine.UI.Extensions
         /// <param name="eventData"></param>
         public override void OnEndDrag(PointerEventData eventData)
         {
+            if (updated)
+            {
+                return;
+            }
+
+            // to prevent double dragging, only act on EndDrag once per frame
+            updated = true;
+
             _pointerDown = false;
 
             if (_scroll_rect.vertical)