Fix timeline curve expanding to properly show whole curve area

Source/Editor/GUI/CurveEditor.Base.cs

@@ -100,6 +100,11 @@ namespace FlaxEditor.GUI
         /// </summary>
         public abstract Type ValueType { get; }
 
+        /// <summary>
+        /// Gets the main container control that holds the curve editor UI. Can be used to add custom controls to the curve editor.
+        /// </summary>
+        public abstract Panel MainPanel { get; }
+
         /// <summary>
         /// The amount of frames per second of the curve animation (optional). Can be used to restrict the keyframes time values to the given time quantization rate.
         /// </summary>

Source/Editor/GUI/CurveEditor.cs

@@ -633,6 +633,9 @@ namespace FlaxEditor.GUI
         /// <inheritdoc />
         public override Type ValueType => typeof(T);
 
+        /// <inheritdoc />
+        public override Panel MainPanel => _mainPanel;
+
         /// <inheritdoc />
         public override float? FPS
         {

Source/Editor/GUI/Timeline/Tracks/CurvePropertyTrack.cs

@@ -292,7 +292,15 @@ namespace FlaxEditor.GUI.Timeline.Tracks
             Height = IsExpanded ? _expandedHeight : CollapsedHeight;
             UpdateCurve();
             if (IsExpanded)
+            {
+                // Layout bug: whole curve showing after track resize needs panel scrolls bars s smoothing disabled and showing twice
+                Curve.MainPanel.VScrollBar?.EnableSmoothing = false;
+                Curve.MainPanel.HScrollBar?.EnableSmoothing = false;
                 Curve.ShowWholeCurve();
+                Curve.ShowWholeCurve();
+                Curve.MainPanel.VScrollBar?.EnableSmoothing = true;
+                Curve.MainPanel.HScrollBar?.EnableSmoothing = true;
+            }
 
             base.OnExpandedChanged();
         }
@@ -311,7 +319,7 @@ namespace FlaxEditor.GUI.Timeline.Tracks
             UpdatePreviewValue();
         }
 
-        /// <inheritdoc />
+        /// <inheritdoc />  
         public override void OnUndo()
         {
             base.OnUndo();