+//! \ingroup Validators
+//! A class to validate a selection for Tangential constraints operation
+class PartSet_TangentSelection : public ModuleBase_SelectionValidator
+{
+ public:
+ PARTSET_EXPORT virtual bool isValid(const ModuleBase_ISelection* theSelection) const;
+};
+
+////////////// Attribute validators ////////////////
+
+
+/**
+* \ingroup Validators
+* A validator which checks that objects selected for feature attributes are different (not the same)
+*/
+class PartSet_DifferentObjectsValidator : public ModelAPI_AttributeValidator
+{
+ public:
+ //! Returns true if the attribute is good for the feature attribute
+ //! \param theAttribute an attribute
+ //! \param theArguments a list of arguments (names of attributes to check)
+ virtual bool isValid(const AttributePtr& theAttribute,
+ const std::list<std::string>& theArguments) const;
+
+protected:
+ //! Checks whethe other feature attributes has a reference to the given attribute
+ //! \param theAttribute a source attribute to find object
+ //! \return a boolean value
+ bool featureHasReferences(const AttributePtr& theAttribute) const;
+};
+
+/**
+* \ingroup Validators
+* A validator which checks that objects selected for feature attributes are different (not the same)
+*/
+class PartSet_SketchEntityValidator : public ModelAPI_AttributeValidator
+{
+ public:
+ //! Returns true if the attribute is good for the feature attribute
+ //! \param theAttribute an attribute
+ //! \param theArguments a list of arguments (names of attributes to check)
+ virtual bool isValid(const AttributePtr& theAttribute,
+ const std::list<std::string>& theArguments) const;
+};
+
+/**\class PartSet_SameTypeAttrValidator
+ * \ingroup Validators
+ * \brief Validator for the tangent constraint input.
+ *
+ * It just checks that distance is greater than zero.
+ */
+class PartSet_SameTypeAttrValidator : public ModelAPI_AttributeValidator
+{
+ public:
+ //! returns true if attribute is valid
+ //! \param theAttribute the checked attribute
+ //! \param theArguments arguments of the attribute
+ virtual bool isValid(const AttributePtr& theAttribute,
+ const std::list<std::string>& theArguments) const;
+};
+
+