Re: AltGR != mod5 in general

[sand blarg net]

Timo Korvola writes:
> r4474 is erroneous because Mod1..Mod5 do not have hard-coded
> semantics.  There is no keysym named AltGR.  The key thus labeled is
> usually bound to the keysym ISO_Level3_Shift and assigned to one of the
> modifier bits Mod1..Mod5.  It could be any one of them.  To check if
> AltGR is being pressed, one must check the modifier map to see which
> bit ISO_Level3_Shift is assigned to, then check whether that bit is
> active.  It is the same procedure as for Meta, Super etc.  Only shift,
> lock and control have fixed modifier bits.

Jamie Zawinski's XKeyCaps manual page has more gory details:

  http://www.jwz.org/xkeycaps/man.html

I also remember seeing C code (which jwz wrote) implementing the
correct behavior in the XEmacs sources.

Derek