On Mon, 5 Sep 2011, Berend Hasselman wrote:
I've been experimenting in Ubuntu 10.04 in VirtualBox.
The behaviour of programs seems to vary.
In Firefox you use the Alt+letter to go to a main menu item and then
- you can keep the Alt key depressed and press an underlined letter
- or you can let go of the Alt key and and press an underlined letter.
The Gnome Commander on the other hand wants you to let go of
the Alt key when you go for a submenu item. Nautilus behaves
in the same way. And Gretl of course.
I'm seeing the same here on native linux.
As an experiment I wrote a minimal test program which just
opens a plain GTK window with a menu. There are at least three
different APIs for constructing a menu in GTK (though maybe
they all come to the same thing internally). Anyway, I tried
building the menu in three ways and in all cases it behaved
like the ones in gretl and gnome apps, as Berend describes.
My tentative conclusion is that apps such as Firefox and
LibreOffice, where both Alt-key and plain key can be used to
select a submenu item with an underlined letter, must be doing
something special to get that effect. In which case I don't
think it's worth bothering with.