Updated VSS / HSS to handle pages with interactable components.

Interactables mess with the Pointer Down/Up events that the control used when a mouse is used, so implementation changes to suit.

--HG--
branch : develop_5.3

Scripts/Layout/HorizontalScrollSnap.cs

@@ -45,17 +45,20 @@ namespace UnityEngine.UI.Extensions
             CurrentPage = GetPageforPosition(_screensContainer.localPosition);
 
             //If the container is moving check if it needs to settle on a page
-            if (!_pointerDown && (_scroll_rect.velocity.x > 0.01 || _scroll_rect.velocity.x < 0.01))
+            if (!_pointerDown)
+            {
+                if (_scroll_rect.velocity.x > 0.01 || _scroll_rect.velocity.x < 0.01)
                 {
                     //if the pointer is released and is moving slower than the threshold, then just land on a page
-                if (IsRectMovingFasterThanThreshold(0))
+                    if (IsRectMovingSlowerThanThreshold(0))
                     {
                         ScrollToClosestElement();
                     }
                 }
             }
+        }
 
-        private bool IsRectMovingFasterThanThreshold(float startingSpeed)
+        private bool IsRectMovingSlowerThanThreshold(float startingSpeed)
         {
             return (_scroll_rect.velocity.x > startingSpeed && _scroll_rect.velocity.x < SwipeVelocityThreshold) ||
                                 (_scroll_rect.velocity.x < startingSpeed && _scroll_rect.velocity.x > -SwipeVelocityThreshold);
@@ -195,6 +198,8 @@ namespace UnityEngine.UI.Extensions
         /// <param name="eventData"></param>
         public void OnEndDrag(PointerEventData eventData)
         {
+            _pointerDown = false;
+
             if (_scroll_rect.horizontal)
             {
                 if (UseFastSwipe)

Scripts/Layout/ScrollSnapBase.cs

@@ -4,7 +4,7 @@ using UnityEngine.EventSystems;
 
 namespace UnityEngine.UI.Extensions
 {
-    public class ScrollSnapBase : MonoBehaviour, IBeginDragHandler, IDragHandler, IPointerDownHandler, IPointerUpHandler
+    public class ScrollSnapBase : MonoBehaviour, IBeginDragHandler, IDragHandler
     {
         internal RectTransform _screensContainer;
         internal bool _isVertical;
@@ -404,6 +404,7 @@ namespace UnityEngine.UI.Extensions
         /// <param name="eventData"></param>
         public void OnBeginDrag(PointerEventData eventData)
         {
+            _pointerDown = true;
             _settled = false;
             StartScreenChange();
             _startPosition = _screensContainer.localPosition;
@@ -418,15 +419,6 @@ namespace UnityEngine.UI.Extensions
             _lerp = false;
         }
 
-        public void OnPointerDown(PointerEventData eventData)
-        {
-            _pointerDown = true;
-        }
-
-        public void OnPointerUp(PointerEventData eventData)
-        {
-            _pointerDown = false;
-        }
         #endregion
     }
 }

Scripts/Layout/VerticalScrollSnap.cs

@@ -45,16 +45,23 @@ namespace UnityEngine.UI.Extensions
             CurrentPage = GetPageforPosition(_screensContainer.localPosition);
 
             //If the container is moving check if it needs to settle on a page
-            if (!_pointerDown && (_scroll_rect.velocity.y > 0.01 || _scroll_rect.velocity.y < -0.01))
+            if (!_pointerDown)
+            {
+                if (_scroll_rect.velocity.y > 0.01 || _scroll_rect.velocity.y < -0.01)
             {
                     // if the pointer is released and is moving slower than the threshold, then just land on a page
-                if ((_scroll_rect.velocity.y > 0 && _scroll_rect.velocity.y < SwipeVelocityThreshold) ||
+                    if (IsRectMovingSlowerThanThreshold(0))
-                    (_scroll_rect.velocity.y < 0 && _scroll_rect.velocity.y > -SwipeVelocityThreshold))
                     {
                         ScrollToClosestElement();
                     }
                 }
+            }
+        }
 
+        private bool IsRectMovingSlowerThanThreshold(float startingSpeed)
+        {
+            return (_scroll_rect.velocity.y > startingSpeed && _scroll_rect.velocity.y < SwipeVelocityThreshold) ||
+                                (_scroll_rect.velocity.y < startingSpeed && _scroll_rect.velocity.y > -SwipeVelocityThreshold);
         }
 
         public void DistributePages()
@@ -191,6 +198,8 @@ namespace UnityEngine.UI.Extensions
         /// <param name="eventData"></param>
         public void OnEndDrag(PointerEventData eventData)
         {
+            _pointerDown = false;
+
             if (_scroll_rect.vertical)
             {
                 if (UseFastSwipe)