Re: RAD, invisible components

[Owen Taylor <otaylor redhat com>]

On Mon, 2003-10-20 at 15:17, Stephan Bayer wrote:
> Ok first,
> the "improvements" i will discuss are only usefull for GUI builder like
> Glade.
> 
> In Tools like Borland Delphi etc. and now in Visual Studio.net there is
> a partition in visual components and none visual components. In gtk and
> Galde we have support for the visual part.
> But in Glade is no support for none visual components (or i'm wrong),
> like a database table connection or something like a socket component.
> In the wide or near feature it would be nice to have such components and
> this feature in Glade.
> My opinion is that this is a big feature wich mainstream development
> needs.
> 
> I think we have two possible solutions for this.
> 
> Solution one:
> Gtk itself doesn't need this feature, but library's depending and
> extending gtk maybe need this. So it would be nice if gtk includes a
> class for this. Library use this class to derive from this and Glade
> know that this is a none visual component. The component only needs a
> property for an icon which the GUI builder display.
> This solution would be the object orient way.

There is no need for GTK+ declare something a non-visual component.
If a GObject derives from GtkWidget, it is a visual component,
and can be handled by code that knows how to handle GtkWidgets

If it *doesn't* derive from GtkWidget, it is either:

 - A non-visual component
 - A visual component that needs special handling (think
   GnomeCanvasItem)

> Solution two:
> We only extend Glade.
> We add the posibility to add none visual components, by declaring this
> in the glade3 xml files or so.
> If this mailing list comes to the solution this would be the way we
> should go, i'm then inform the glade list to implement such a feature.

I'm sure they'll be delighted to learn of your interest in implementing
such a thing.

I don't think generic handling of non-visual components is all that
useful, though there is clearly need in Glade for GtkTreeModel,
GtkTreeViewColumn, GtkSizeGroup, etc.

There does need to be some improvements in libglade's interfaces to
handle this, since it currently always returns a GtkWidget *.

Regards,
						Owen