Scroller behaviour improvements

setchi · Dec 10, 2019 · bf3fd36 · bf3fd36
1 parent 88ecf54
commit bf3fd36
Showing 1 changed file with 76 additions and 3 deletions.
diff --git a/Assets/FancyScrollView/Sources/Runtime/Scroller/Scroller.cs b/Assets/FancyScrollView/Sources/Runtime/Scroller/Scroller.cs
@@ -15,7 +15,7 @@ namespace FancyScrollView
     /// <summary>
     /// スクロール位置の制御を行うコンポーネント.
     /// </summary>
-    public class Scroller : UIBehaviour, IBeginDragHandler, IEndDragHandler, IDragHandler
+    public class Scroller : UIBehaviour, IPointerUpHandler, IPointerDownHandler, IBeginDragHandler, IEndDragHandler, IDragHandler, IScrollHandler
     {
         [SerializeField] RectTransform viewport = default;
 
@@ -154,6 +154,8 @@ public float Position
 
         int totalCount;
 
+        bool hold;
+        bool scrolling;
         bool dragging;
         float velocity;
 
@@ -314,6 +316,75 @@ public MovementDirection GetMovementDirection(int sourceIndex, int destIndex)
                     : MovementDirection.Down;
         }
 
+        /// <inheritdoc/>
+        void IPointerDownHandler.OnPointerDown(PointerEventData eventData)
+        {
+            if (!draggable || eventData.button != PointerEventData.InputButton.Left)
+            {
+                return;
+            }
+
+            hold = true;
+            velocity = 0f;
+            autoScrollState.Reset();
+        }
+
+        /// <inheritdoc/>
+        void IPointerUpHandler.OnPointerUp(PointerEventData eventData)
+        {
+            if (!draggable || eventData.button != PointerEventData.InputButton.Left)
+            {
+                return;
+            }
+
+            if (hold && snap.Enable)
+            {
+                UpdateSelection(Mathf.Clamp(Mathf.RoundToInt(currentPosition), 0, totalCount - 1));
+                ScrollTo(Mathf.RoundToInt(currentPosition), snap.Duration, snap.Easing);
+            }
+
+            hold = false;
+        }
+
+        /// <inheritdoc/>
+        void IScrollHandler.OnScroll(PointerEventData eventData)
+        {
+            if (!draggable)
+            {
+                return;
+            }
+
+            var delta = eventData.scrollDelta;
+
+            // Down is positive for scroll events, while in UI system up is positive.
+            delta.y *= -1;
+            var scrollDelta = scrollDirection == ScrollDirection.Horizontal
+                ? Mathf.Abs(delta.y) > Mathf.Abs(delta.x)
+                        ? delta.y
+                        : delta.x
+                : Mathf.Abs(delta.x) > Mathf.Abs(delta.y)
+                        ? delta.x
+                        : delta.y;
+
+            if (eventData.IsScrolling())
+            {
+                scrolling = true;
+            }
+
+            var position = currentPosition + scrollDelta / ViewportSize * scrollSensitivity;
+            if (movementType == MovementType.Clamped)
+            {
+                position += CalculateOffset(position - currentPosition);
+            }
+
+            if (autoScrollState.Enable)
+            {
+                autoScrollState.Reset();
+            }
+
+            UpdatePosition(position);
+        }
+
         /// <inheritdoc/>
         void IBeginDragHandler.OnBeginDrag(PointerEventData eventData)
         {
@@ -322,6 +393,7 @@ void IBeginDragHandler.OnBeginDrag(PointerEventData eventData)
                 return;
             }
 
+            hold = false;
             RectTransformUtility.ScreenPointToLocalPointInRectangle(
                 viewport,
                 eventData.position,
@@ -452,7 +524,7 @@ void Update()
 
                 UpdatePosition(position);
             }
-            else if (!dragging && (!Mathf.Approximately(offset, 0f) || !Mathf.Approximately(velocity, 0f)))
+            else if (!(dragging || scrolling) && (!Mathf.Approximately(offset, 0f) || !Mathf.Approximately(velocity, 0f)))
             {
                 var position = currentPosition;
 
@@ -503,13 +575,14 @@ void Update()
                 }
             }
 
-            if (!autoScrollState.Enable && dragging && inertia)
+            if (!autoScrollState.Enable && (dragging || scrolling) && inertia)
             {
                 var newVelocity = (currentPosition - prevPosition) / deltaTime;
                 velocity = Mathf.Lerp(velocity, newVelocity, deltaTime * 10f);
             }
 
             prevPosition = currentPosition;
+            scrolling = false;
         }
 
         float CalculateMovementAmount(float sourcePosition, float destPosition)