Re: [PATCH] Database shapes and start arrow

[Hans Breuer <hans breuer org>]

At 26.04.2012 01:16, Jim Ursetto wrote:
> On Apr 25, 2012, at 2:58 PM, Hans Breuer wrote:
>
> > At 25.04.2012 00:36, Jim Ursetto wrote:
[...]
> > > OK.  But I don't see how to set the default value for a missing optional
> > > property.  It seems to set to the object creation default, which will be
> > > whatever the current default start arrow is at load time; this is
> > > obviously wrong.  I need to override this to "no arrow" when loading an
> > > old file.  Suggestions?
> > Look at e.g. http://git.gnome.org/browse/dia/commit/?id=aeb71aca
> > for an example.
>
> I've made the value optional and suppressed the warning in
> my own copy prior to my last mail.
>
> However, this commit doesn't appear to address the problem above,
> as it hardcodes the default value to color_black (or white).
> This does not work for the start arrow case, because the start
> arrow type is taken from the current setting in the toolbox,
> so it cannot be hardcoded.
The initialization to:
  ref->start_arrow = attributes_get_default_start_arrow ();
is in _your_ patch. So I fail to see the problem to change that code to 
default to _no_ arrow.

> As I said above, if you load a file with a missing start
> arrow and the attribute is optional, it takes on the value
> given in the create function--which is the current value set
> in the toolbox.  Obviously, this is wrong--you should not
> have your drawing changed when loading it.
The optional is just about complaining about missing attributes (for old 
files). It does not mean that new files will not contain the saved proeprty.

> Hardcoding the start arrow value to none works at load time but then
> you cannot set the default using the toolbox.
Yes, and that perfectly fine IMO. Of course on also could use the 
per-object version information to conditionally overwrite the default 
initiailization in a specific _load method.

> So, a solution for this is needed, if possible.
>
> > Still I'm not convinced that an extra start arrow is an improvement at all.
>
> The intent was to support things like crow's foot notation, which
> uses arrows on both sides.
Soory, I fail to see any correlation between database references and crow's 
foot notation.

-------- Hans "at" Breuer "dot" Org -----------
Tell me what you need, and I'll tell you how to
get along without it.                -- Dilbert