Global menubar (was Re: #4 on ToDo list: make the top panel prettier)

[Owen Taylor <otaylor redhat com>]

[ resending from a thread that accidentally drifted off-list ]

On Mon, 2009-01-19 at 20:34 +0100, Jonas Jørgensen wrote:
> 2009/1/19 Owen Taylor <otaylor redhat com>:
> > On Sun, 2009-01-18 at 19:14 -0800, Brian Fleeger wrote:
> >> I have one question: with the part of the top panel next to the
> >> activities button empty, are there any plans to use global menus to
> >> more effectively use that wide open space?  Is it going to go fallow?
> [...]
> > I have some opinion that the global menu bar is pretty tied to
> > the application-centric model of the Macintosh .. it's not entirely
> > clear to me that you can go to the global menu bar without adopting that
> > model wholesale. Which would be a pretty major change to the way the
> > desktop works.
> 
> I'm curious as to why you have that opinion, and I'd love to hear an
> explanation of it -- because I strongly prefer the
> menu-bar-in-top-panel approach, and I strongly dislike the
> application-centricism of Mac OS :-)

Well, on the Macintosh, to really use the computer effectively, you do
have to understand the concept of an application being "current". This
is exposed, among other things by:

 - All windows of an application come to the front at one
 - The ability to "hide other windows" to hide windows not from the 
   application
 - The menubar staying there when you close the last window
 - The dock icons activating an application

The global menu is part of the "bundle" of concepts.

On a Linux (or for that matter Windows) desktop, if I'm only working
with maximized windows, then there is a clear stand-in for the current
application, which is the maximized window. In that case, I think the
global menu does work OK - it's really just shuffling around the stuff
at the top of the screen.

But large monitors have become cheap and common (22" could be said to
be the standard size at this point), and multiple monitors are not
unusual. Given sufficient real estate, most people stop maximizing all
their windows. And at that point, I think that it's a leap to say that
selecting something in one corner of the screen changes something all
the way at the other corner of the screen.

You might say that the global menu is just an extension of the concept
of keyboard focus. Here's two predictions I'll make about keyboard focus
on a large monitor with non-maximized windows based on
"locality" (completely unsubstantiated from actual data)

- Users will keep the mouse over or near the window they are typing on,
  even when that requires extra effort. 
- Users will occasionally click on an already focused window before
  starting to type in it.

In other words, the user doesn't really have a strong mental model that
there is global focused window that applies even when there their
eyes, attention, and mouse cursor are elsewhere.

There are also some corner cases to the global menu model that have
obvious answers in the "application" case, but less obvious answers in
the "window" case. Do all windows from the same application have the
same menu bar?  What happens with windows without a menu bar? (From an
app with other windows? As a standalone app?)

- Owen