creat edg given type connect given node param graph model graph model creat connect element param edg type uml object type connect param sourc fig fig node sourc element param dest fig fig node destin element fig edg repres newli creat model element overrid fig edg build connect mutabl graph model graph model object edg type fig sourc fig fig dest fig sourc associ end classifi user drawn wrong wai round swap sourc fig fig classifi box fig temp fig sourc fig sourc fig dest fig dest fig temp fig object associ end model uml factori build connect edg type sourc fig owner dest fig owner fig node sourc fig node convert fig node sourc fig fig node dest fig node convert fig node dest fig graph model add edg associ end set edg associ end call connect add edg graph model layer persect graph model edg ad event add appropri fig edg determin graph edg render edg sourc fig node damag dest fig node damag layer lai editor layer manag activ layer fig edg fe fig edg lai present edg item set line color color black fe set fig item fe set sourc port fig sourc fig node fe set sourc fig node sourc fig node fe set dest port fig dest fig node fe set dest fig node dest fig node fe illeg model element connect except confirm connect valid 