Re: row and column size not being preserved when switching X displays

[Jody Goldberg <jody gnome org>]

On Fri, Nov 05, 2004 at 09:32:07PM +0000, Joe Wells (reverse mailbox letters only for non-public replies) 
wrote:
> There's an important bit of information in my report that I failed to
> emphasize and I am not sure it was obvious to all of you folks why it
> is important.  Here is the important bit of information:
>
>   *PART* of Gnumeric *ALREADY*IS* paying attention to the dpi reported
>   by the X server and another part is not.
>
> I am guessing the part that is paying attention is one of the GNOME
> libraries that deals with font issues.
 
I'm not so sure.  We scale the fonts by our notion of the dpi too.

> Currently what this means is that I have to invoke some command (I
> forget the details) to edit the GConf registry every time I *start*
> Gnumeric to make sure the dpi value stored in GConf matches the X
> server's dpi.  If I want to run two copies of Gnumeric simultaneously
> on the same machine, but using two different displays, I have to edit
> the GConf registry after starting the first copy but before starting
> the second.

Unfortunately yes.  I'll have a look at supporting something like
dpi < 0 => use the screen dpi.
 
> Can't Gnumeric just use the same code used by the other GNOME library
> (whichever one Gnumeric is using that is noticing the X server's
> reported dpi)?  Is there no standard GNOME way for this to work?  Or
> is each GNOME library and application going to figure out the dpi to
> use in a way that is not guaranteed to make them all match?

There is a gtk call to get the dpi.  It is based on the Xlib call.
Unfortunately, X was notoriously wrong when we wrote the code, and
has only improved recently.  XL also makes some assumptions about
dpi and seems to fix it at 96 as far as I can tell.

> As a completely separate question, why does this affect printing at
> all?
It shouldn't

> How can printing possibly be dependent on the dpi of the X server?
It's not.

I suspect that what you're seeing is a distinct problem.  Font's do
not scale linearly and until you are using pango-1.6 things are not
going to be lined up quite the same way.  This is an area that needs
work.