Re: Better with units

[Lars Clausen <lrclause cs uiuc edu>]

On Tue, 28 Aug 2001, Robert Young wrote:

> Dolores Alia de Saravia wrote:
>
> >  Dia deals with three different  length magnitudes: 
> > ---  one for paper, or printed diagram;  unit: cm
> > ---  one for canvas, or working diagram; unit without a name, it could
> > be "virtual cm", or simply  "canvas_unit".  
> > ---  one for the window trough which we see part of the canvas; unit: 
> > pixel.
> >
> >  I  beleive it would be better (less confusing) to make the user aware
> > of the units.
>
> I agree with making the user aware of the units (it would mean that dia
> could be used for rudimentary CAD!).
>
> I think, however, that it would be useful to be able to set the default
> units in the Preferences dialog (ft, cm, mm, m, pt, inch, nmi, lyr etc)
> and then all the dialogs display values in terms of this e.g. line
> thickness, grid spacing. Lars originally suggested something like this
> (Re: StdProp overhaul, take 2 on 14/8/01). The only pixel unit would be
> the new window width and height (though I have other ideas about this -
> new window defaults to A4 with 10% 'bleed' area with all of this
> selectable).
>
> The "virtual cm", or simply  "canvas_unit" concerns me because it is not
> obvious to a user what it is. Even the word pixels may confuse the user.

Unless we make the window dimensions match the screen dimensions (currently
"100% zoom" does not mean that one cm in the diagram shows up as one cm on
the screen.  In fact, with the 'Fit to' page setup, we would need to zoom
in and out all the time.), the user should be able to specify the window
dimensions.

> To ease the implementation, the dia_unit_spinner could be used (see
> app/diaunitspinner.[ch]). Currently (AFAIK) the only place it is used is
> the paper size dialog - try typing 2ft for the page width and it cleverly
> converts it to cm! - cool, James)

Letting the input boxes convert from various units is cool, but we need to
let the unit converted _to_ be changed.  We'd also need to add a number of
frequently used unit designations, like "ft" and "feet".  Also, the font
size input boxes should probably use a separate unit -- many people like to
have 'points' for font units.

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause) | Hårdgrim of Numenor
"I do not agree with a word that you say, but I    | Retainer of Sir Kegg
will defend to the death your right to say it."    |   of Westfield
    --Evelyn Beatrice Hall paraphrasing Voltaire   | Chaos Berserker of Khorne