Re: Keys when menu-bar is active?

[Eli Zaretskii]

> From: "Stefan Monnier" <monnier+gnu/address@hidden>
> Date: Thu, 24 Jan 2002 19:13:04 -0500
> 
> > >> * Due to the changing size, you can't use it to reliably indicate
> > >>   how many lines are above you and how many lines below you.
> > > I'm not sure I understand.  It does reliably indicate something else.
> > Yes, ok.  Since it doesn't indicate the same thing as in other
> > programs using Xaw widgets, it is not inutive what it does indicate.
> 
> They both indicate via the thumb size some approximate idea of
> the fraction of text that's visible.
> Admittedly, what we really would want is that the "fraction" is
> not based on lines (as in xterm) or on chars (as in Emacs right now)
> but on vertical pixel size.  That's actually what xterm does
> (since its lines all have the same pixel height), but doing that
> in Emacs would be awfully costly (you'd have to render the whole
> buffer in order to find the total pixel size).

Couldn't we simply take the window height, divide that by the
canonical character height (stored in frame's output_data.x
structure), and use that as an approximation for the amount of text
that is displayed?  I know this is not very accurate (in some cases it
will be grossly inaccurate), but it's consistent, so the relative size
of the thumb will give a correct indication of what users want to
know: the portion of the buffer that is displayed.