+ /// Checks all widget validator if the owner is valid. Firstly it checks custom widget validating,
+ /// next, the attribute's validating. It trying on the give selection to current attribute by
+ /// setting the value inside and calling validators. After this, the previous attribute value is
+ /// restored.The valid/invalid value is cashed.
+ /// \param theValue a selected presentation in the view
+ /// \return a boolean value
+ virtual bool isValidSelection(const ModuleBase_ViewerPrs& theValue);
+