+ /// Returns true, if default value of the widget should be computed
+ /// on operation's execute, like radius for circle's constraint (can not be zero)
+ bool isComputedDefault() const { return myIsComputedDefault; }
+
+ /// Returns true, if default value of the widget is defined in the XML and it is not the
+ /// computed value
+ /// \return the boolean result
+ std::string getDefaultValue() const { return myDefaultValue; }
+
+ /// Returns true, if the obligatory value of the widget is not defined in the XML or has true value
+ /// \return the boolean result
+ bool isObligatory() const { return myIsObligatory; }
+
+ /// Defines if it is supposed that the widget should interact with the viewer.
+ virtual bool isViewerSelector() { return false; }