RE: Better with units

["Young, Robert" <Robert Young dsto defence gov au>]

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.

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)

Anyway, just my thoughts.

Regards,
Rob.