drag handl handl hand don allow drag outsid bound diagram math max math max hand index set paint button drag handl hand draggabl handl hand index cx content cy content cw content width ch content height bx rememb handl click drag releas space button hand index hand index cy bx cx cw cy ch bx cx cw left cy ch bx cx right cy ch bx cx cw lower left cy ch bx cx defin log lp log granular type statement lp log local nest statement log warn invalid handl number endif object node type node type hand index object edg type edg type hand index revers revers edg hand index edg type node type editor ce global cur editor mode creat edg node mode creat edg node ce edg type edg post process request setup fig node content content owner bx revers ce push mode 