Re: GtkGrid design document

[Jonathan Blandford <jrb redhat com>]

Lorenzo Gil Sanchez <lgs sicem biz> writes:

> I'd love to see that in GtkTreeView since that is what I was asking for
> some time ago. Don't get me wrong, I have enjoyed and learned a lot
> while writting the grid widget but at the beginning the only reason I
> start writing was because it was absolutely needed in my project and I
> got frustrated with the TreeView.

I would imagine that fixing TreeView will be easier than writing a new
widget from scratch. (-;

> I suppose I was (and I am) too unexperienced to add such behaviour to
> the TreeView but it people think it is worthy I will be happy to help
> enhacing the TreeView this way.
> 
> > On the other hand, there are certainly cases where you want something
> > different from GtkTreeView:
> > 
> >  - Efficient handling of many columns and sparse data
> Do you mean here that the header shouldn't be made from GtkButtons and
> only made of a regular gdkwindow? I guess that would allow to have 10k
> columns without memory worries.

Not necessarily the headers, but more importantly handling a sheet with
a large number of rows/columns, but only partially filled in.  You don't
want to needlessly allocate memory for the entire area.  But perhaps
this is more of a data-model issue.  I haven't really thought through
the issues with this widget.

It does raise another issue.  It seems like the GtkTreeModel interface
might be a bad fit for a grid widget, as it is inherently row based.
You might want to think about having a GtkGridModel interface (that the
GtkListStore could implement).

> >  - Rectangular selection
> > 
> This is planned but still need to be studied since all the cells of the
> same column share the same type it will be difficult to allow random
> copy and paste of rectangular selections.

I imagine cut-n-paste working only a homogenous setup won't surprise the
user...

> > But I don't have a good sense of what apps would use such a widget
> > at the moment. Having that idea is core to designing the widget.
> 
> Just because we don't have any famous GNOME application that need it I
> don't think there is no neccesity for such a widget. Maybe home users
> don't really need this kind of programs but they are a must for company
> users. Here in Spain most of the small and medium size companies use
> some Access customized program to solve their needs so I guess the user
> base is potentially pretty.

Sounds like a reasonable start.

-Jonathan