Fixes for UI editor changes

Source/Editor/Gizmo/UIEditorGizmo.cs

@@ -21,9 +21,12 @@ namespace FlaxEditor
 
         public void ShowActors(IEnumerable<Actor> actors)
         {
+            var root = UIEditor.UIRoot;
+            if (root == null)
+                return;
+
             // Calculate bounds of all selected objects
             var areaRect = Rectangle.Empty;
-            var root = UIEditor.UIRoot;
             foreach (var actor in actors)
             {
                 Rectangle bounds;
@@ -163,7 +166,7 @@ namespace FlaxEditor
         /// <summary>
         /// True if enable panning and zooming the view.
         /// </summary>
-        public bool EnableCamera => _view != null;
+        public bool EnableCamera => _view != null && EnableBackground;
 
         /// <summary>
         /// Transform gizmo to use sync with (selection, snapping, transformation settings).
@@ -293,7 +296,7 @@ namespace FlaxEditor
                 return true;
             }
 
-            return false;
+            return Focus(this);
         }
 
         public override void OnMouseMove(Float2 location)
@@ -467,7 +470,7 @@ namespace FlaxEditor
 
         public override void Draw()
         {
-            if (EnableBackground)
+            if (EnableBackground && _view != null)
             {
                 // Draw background
                 Surface.VisjectSurface.DrawBackgroundDefault(Editor.Instance.UI.VisjectSurfaceBackground, Width, Height);

Source/Editor/Viewport/EditorViewport.cs

@@ -1537,7 +1537,7 @@ namespace FlaxEditor.Viewport
                 }
                 bool useMouse = IsControllingMouse || (Mathf.IsInRange(_viewMousePos.X, 0, Width) && Mathf.IsInRange(_viewMousePos.Y, 0, Height));
                 _prevInput = _input;
-                var hit = GetChildAt(_viewMousePos, c => c.Visible && !(c is CanvasRootControl));
+                var hit = GetChildAt(_viewMousePos, c => c.Visible && !(c is CanvasRootControl) && !(c is UIEditorRoot));
                 if (canUseInput && ContainsFocus && hit == null)
                     _input.Gather(win.Window, useMouse);
                 else

Source/Editor/Viewport/Previews/PrefabPreview.cs

@@ -114,6 +114,8 @@ namespace FlaxEditor.Viewport.Previews
                 _uiControlLinked = uiControl;
                 _hasUILinked = true;
             }
+            else if (_uiControlLinked != null)
+                _hasUILinked = true;
         }
 
         private void LinkCanvas(Actor actor)