[Gramps-bugs] Re: GraphViz (relationship) chart oddities

[Alex R. <sh...@gr...>]

Eero,

On 07/05/2005 02:38:34 PM, Eero Tamminen wrote:
>=20
> > > * Although I select 1x1 pages for the output, the report generates 4
> > > pages (of which 3 have *very* little content).  This happens with
> > > margins set to zero.  If I set the margins to one, then there's only
> > > one page of output. A possible explanation for this could be that wit=
h
> > > zero margins set in the GUI, the generated dot file still seems to li=
st
> > > margin as 0.5 (and have only one margin value...):
> > > -----
> > >  *   margins top/bottom : 0.0
> > >  *           left/right : 0.0
> > >  *   pages horizontal   : 1
> > >  *         vertical     : 1
> > >  *   page width         : 8.26771653543in
> > >  *        height        : 11.6929133858in
> > > ...
> > > center=3D1;
> > > margin=3D0.5;
> > > size=3D"8.3,11.7";
> > > page=3D"8.3,11.7";
> > > ------
> >
> > The dot format seem to want one margin value, default is 0.5 in.
> > The GUI-provided margins are used to calculate the height/width
> > in "size" compared to "page". Zero margins mean that size equals
> > page.
> >
> > I am not certain what is the role of "margin" value
>=20
> Dot man page says:
> "sets the page margin (included in the page size)."
>=20
> Report "page" .dot setting AFAIK comes from the Gramps/printing page
> setting. "size" sets bounding box of drawing, i.e. the "virtual" page siz=
e
> (which can span multiple physical pages).
>=20
> So... "margin" is associated with "page", whereas the  margin settings  i=
n
> the UI dialog are associated with the "size" (drawing bounding box).
>=20
>=20
> > -- should we=20
> > specify left/right or top/bottom margin? I thought of making it
> > min(left_right,top_bottom), but I am not sure.
>=20
> I tested setting:
> 	margin=3D0.0
> in the .dot file and that fixed the output for single page with top/botto=
m
> and left/right margins set to 0.0 in the UI (both for single and multiple
> pages).
>=20
> However, when looking at the code:
>         self.f.write("margin=3D0.5;\n")
>         self.f.write("size=3D\"%3.1f,%3.1f\";\n" % (
>                 (self.width*self.hpages)-(self.lr_margin*2)
>                         -((self.hpages-1)*1.0),
>                 (self.height*self.vpages)-(self.tb_margin*2)
>                         -((self.vpages-1)*1.0))
>         )
>=20
> I'm not sure what the  "-((self.hpages-1)*1.0)" is for.
> Is "*1.0" supposed to be "*2*margin"?
>=20
> For printing you probably need a page margin in addition to the bounding =
box
> margin as all printers (e.g. my deskjet) cannot print to the full page
> size...  I.e. unfortunately it cannot be zero.  In some printers some mar=
gin
> (bottom?) can be as large as one inch.

All of this makes perfect sense, however I am as clueless as before:

   What would be the proper "margin" value, if I know physical page
   size and the user-entered left_right and top_bottom margins?


> While testing this, I noticed another oddity:
> - After setting the margins once to zero, changing them to another value,
>   OK'ing the dialog and reopening the dialog still presented the margins =
as
>   zero.  Don't they get saved properly?

They should be, so I guess it's a bug. I'll take a look,
Alex

--=20
Alexander Roitman   http://www.gramps-project.org