I'm late to this one, but here goes anyway...

I'm "uncomfortable" (as others have been) about dropping this in as a replacement for the existing menu system - I'm pretty sure that would cause more pain, at least in the short term. In particular, changing the "base" widget to Fl_Group rather than Fl_Widget seems like it might cause "surprises" out in the wild... and there might be ABI issues with that? (Though that's maybe less of a worry for 1.4, which has never been "released"...)

That being said, a new "widget style" menu system might be worth a shot and should bring advantages - this is the way fltk2 went, I think? 

So: If we're picking names, I like the sound of Fl_Widget_Menu_* for this...

Beyond that, Lauri flags a few things: 

- I'm not sure that drawing performance will be that much of a setback - IIRC this sort of approach worked fine on fltk2, and that would generally have been on less capable hardware than folks have nowadays. Nonetheless, something we might need to keep an eye on.

- Menu sizes; it may be useful to have the menu lines scalable, but the usability aspect might well come into play if the menu item is "too small" to be clickable, so we might need some min/max bounds for this and/or (as Lauri suggests) a means to inhibit the scaling. From a usability perspective, it is "normal" to make all the items the "same size" as that makes usage more consistent - "least surprise" and all that...