Fixed regression of cursor being stuck in default when trying to change it in viewport

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

@@ -23,6 +23,8 @@ namespace FlaxEngine.GUI
         private float _splitterValue;
         private Rectangle _splitterRect;
         private bool _splitterClicked, _mouseOverSplitter;
+        private bool _leftMouseButtonDown;
+        private bool _rightMouseButtonDown;
 
         /// <summary>
         /// The first panel (left or upper based on Orientation).
@@ -167,7 +169,7 @@ namespace FlaxEngine.GUI
             {
                 Cursor = _orientation == Orientation.Horizontal ? CursorType.SizeWE : CursorType.SizeNS;
             }
-            else
+            else if (!_leftMouseButtonDown && !_rightMouseButtonDown)
             {
                 Cursor = CursorType.Default;
             }
@@ -178,6 +180,16 @@ namespace FlaxEngine.GUI
         /// <inheritdoc />
         public override bool OnMouseDown(Float2 location, MouseButton button)
         {
+            if (button == MouseButton.Left)
+            {
+                _leftMouseButtonDown = true;
+            }
+            
+            if (button == MouseButton.Right)
+            {
+                _rightMouseButtonDown = true;
+            }
+
             if (button == MouseButton.Left && _splitterRect.Contains(location))
             {
                 // Start moving splitter
@@ -192,6 +204,16 @@ namespace FlaxEngine.GUI
         /// <inheritdoc />
         public override bool OnMouseUp(Float2 location, MouseButton button)
         {
+            if (button == MouseButton.Left)
+            {
+                _leftMouseButtonDown = false;
+            }
+            
+            if (button == MouseButton.Right)
+            {
+                _rightMouseButtonDown = false;
+            }
+            
             if (_splitterClicked)
             {
                 EndTracking();