Re: [Emacs-diffs] /srv/bzr/emacs/trunk r103444: * lisp/facemenu.el (list-colors-display): Use with-help-window (Bug#8048).

[Eli Zaretskii]

> Date: Wed, 02 Mar 2011 09:09:33 +0100
> From: martin rudalics <address@hidden>
> CC: Stefan Monnier <address@hidden>, address@hidden, 
>  address@hidden
> 
>  > Would it help to have a primitive that returns the width in pixels
>  > that a given buffer substring would take on the screen?
> 
> Not really.

Why not?  Especially since you go one explaining why it _would_ be
helpful ;-)

> But in general, a primitive that returned the displayed pixel
> height/width of a substring of any buffer line for some given window
> would be great.

What's a window got to do with this?  How can a window affect display
of a buffer substring?

> Actually, it would be nice if redisplay could cache these values on
> demand for each line it (virtually) displayed.

What for?