[Inkscape-devel] Signals Help

Hi all, I have a conceptual doubt. Suppose widget A houses widget B which hereby houses widget C. Can I associate same strings "changed", "updated" etc.. with individual signals of each widget A,B,C. Also, when I emit a "changed" signal will all three widgets execute their call backs ? Because A <-- B <--- C ( A <--- B means A contains B) and so C when emits "changed" should call callbacks of A and B ?