Tweaks and improvements for curves editing

#519

Source/Engine/UI/GUI/Panels/Panel.cs

@@ -172,6 +172,15 @@ namespace FlaxEngine.GUI
             base.SetViewOffset(ref value);
         }
 
+        /// <summary>
+        /// Cuts the scroll bars value smoothing and imminently goes to the target scroll value.
+        /// </summary>
+        public void FastScroll()
+        {
+            HScrollBar?.FastScroll();
+            VScrollBar?.FastScroll();
+        }
+
         /// <summary>
         /// Scrolls the view to the given control area.
         /// </summary>

Source/Engine/UI/GUI/Panels/ScrollBar.cs

@@ -182,6 +182,19 @@ namespace FlaxEngine.GUI
             _orientation = orientation;
         }
 
+        /// <summary>
+        /// Cuts the scroll bar value smoothing and imminently goes to the target scroll value.
+        /// </summary>
+        public void FastScroll()
+        {
+            if (!Mathf.NearEqual(_value, _targetValue))
+            {
+                _value = _targetValue;
+                SetUpdate(ref _update, null);
+                OnValueChanged();
+            }
+        }
+
         /// <summary>
         /// Scrolls the view to the desire range (favors minimum value if cannot cover whole range in a bounds).
         /// </summary>