[Glade-users] gtk drawing area with gtkglext and glade3

[Tristan Van Berkom]

On Thu, Sep 6, 2012 at 4:25 AM, Tristan Van Berkom <tvb at gnome.org> wrote:
> On Thu, Sep 6, 2012 at 4:07 AM, Roland Graham <r.graham at skrltool.com> wrote:
>> Please help. I have an application that was using glade2 and I am
>> trying to convert it to glade3. It has four gtk_drawingareas configured
>> inside a main window. With glade2 I was able to initialize these
>> drawing areas with gtk_drawingarea_new and the areas were realized and
>> everything worked fine.
>>
>> Under glade3, I do not know how to call the drawingarea_new function,
>> as they are created inside the gtk_builder_add_from_file function as
>> g_objects. When I call the gtk_widget_set_gl_capability function after
>> creating glconfig[i] with gdk_gl_config_new_by_mode, it fails because
>> the drawing area has not been realized. Is there a way to realize these
>> drawing areas after they have been set up? I can create my own drawing
>> areas and the set_gl_capability function works ok, but then how do I
>> connect them to the widget structure?
>>
>> I am an engineer and program only to do various chores, so I am only
>> semi-fluent in these things. Please help!
>
> Its not entirely clear to me what is the order of events needed, when you
> say realize /after being setup/ you only mean, after creating the drawing
> areas ? and before doing the GtkGLExt magic on them ?
>
> The best way to do this I think would be to subclass GtkDrawingArea
> and override the ->realize() method on your custom GtkGLExtDrawingArea
> widget class, then you would chain up before calling the custom gl stuff
> you need. This would work in a reliable and centralised way in the sense
> that you can then simply reuse that drawing area widget in multiple places
> without ever having to remember this detail again.
>
> Other then that, you should be able to manually call gtk_widget_realize()
> on the created drawing area after obtaining it from the interface built with
> GtkBuilder and before displaying the toplevel window.
>
> Hope this helps
>

I forgot to mention, once you've created a GtkDrawingArea subclass, you
can include that in Glade's palette with a simple xml file like this:

<glade-catalog name="foo" supports="gtkbuilder" depends="gtk+">
  <glade-widget-classes>
    <glade-widget-class name="FooGLArea" generic-name="FooGLArea"
                        title="GLArea" parent="GtkDrawingArea">
    </glade-widget-class>
  </glade-widget-classes>
  <glade-widget-group name="foo-widgets" title="Foo Widgets">
    <glade-widget-class-ref name="FooGLArea"/>
  </glade-widget-group>
</glade-catalog>

This will allow you to add your custom "Foo" catalog to Glade's palette
containing the FooGLArea object deriving from GtkDrawingArea in
a simple way... it's all in the developer documentation but I thought
I'd mention it anyway.

After creating the catalog, just place it in a directory and set
GLADE_CATALOG_SEARCH_PATH to search that directory
before starting Glade.

Cheers,
          -Tristan



> Cheers,
>          -Tristan
>
>
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