Is there any Custom widget like the BluePrint or FlowGraph ?

[opengpu]

is there any Custom widget like the BluePrint or FlowGraph as shown below?
if not, is there any good idea to realize it? a custom widget inherit from Listbox, and what lib should be used to draw the curves?
the pic is shown below, as i can't insert them here...
http://fc06.deviantart.net/fs71/f/2014/084/4/9/t6_by_zerodollarz-d7bmcno.png
http://staraban.com/wp-content/uploads/2014/03/unreal-engine-4-blueprint-editor.jpg
Thanks very much!

[Closed thread. Duplicate of http://qt-project.org/forums/viewthread/45769/ --JKSH]