A very rough fltk 1.x port of pyrgen's original fltk2/GPLv2 "TableBox" widget (0.9.x) up on google code which was posted on FLTK's Links page at https://www.fltk.org/links.php?V339+Q back in 2007 I think.
I made this port mainly to just explore the widget. I couldn't get the old + abandoned fltk2 toolkit
to build with modern compilers, so I tried hacking TableBox's code to roughly port it to build
with fltk 1.4.x. While it builds and the test program now runs, I'm not sure it fully works
as expected -- needs more work. Here's a 
Perhaps someone else more motivated than I can take this rough port as a starting point for a cleaner implementation; feel free to fork and continue.
The main things I had to tweak to do the port (and should probably be checked):
* The fltk2 layout() virtual which TableBox overloads, does not exist in fltk 1.x,
had to do some code gymnastics to get that method to be invoked; once after widgets
are initially created (to position/size everything to their initial positions),
and again whenever there's a resize(). So I kinda hacked that, perhaps not completely.
* I emulated the fltk2 methods is_group() and is_window() using C++'s 's typeid().
Not sure this works as intended
Someone cleaning this port up would want to look carefully at my diffs from the original pyren code (4b6dbbb) with white space disabled and look for problems.