+ virtual ObjectPtr object(const QModelIndex& theIndex) const = 0;
+
+ //! Returns QModelIndex which corresponds to the given feature
+ //! If the feature is not found then index is not valid
+ virtual QModelIndex objectIndex(const ObjectPtr& theFeature) const = 0;
+
+ //! Returns parent index of the given feature
+ virtual QModelIndex findParent(const ObjectPtr& theObject) const = 0;
+
+ //! Returns index corresponded to the group
+ virtual QModelIndex findGroup(const std::string& theGroup) const = 0;
+
+ void setItemsColor(const QColor& theColor) { myItemsColor = theColor; }
+
+ QColor itemsColor() const { return myItemsColor; }