Re: Gtk::BuilderError Invalid object type GtkSourceView

[Scott Talbert <swt techie net>]

On Thu, 19 Mar 2015, Stefan Salewski wrote:

> in the last months I was working on GTK3 bindings for the Nim
> programming language (http://nim-lang.org/). Now that they are nearly
> complete (https://github.com/StefanSalewski?tab=repositories) I tried to
> make some example code. One is the gtksourceview test-completion.c
> example, currently from gtk 3.12. Works fine, with one difference
> between C original and my Nim one: Without any modifications I get an
> error message about "Invalid object type GtkSourceView" from Nim
> equivalent of gtk_builder_add_from_file(builder, "test-completion.ui",
> &error). I can easily fix that by putting a dummy allocation like "var
> h1 = view_new()" in front of gtk_builder_add_from_file() call. I think
> something like "gtk_source_view_get_type()" may work also. I think that
> will register the gtk_source_view gobject, and then builder can use it.
> People using GTKmm or Python reports from similar problems, see
> http://comments.gmane.org/gmane.comp.gnome.devtools/1390 or
> http://stackoverflow.com/questions/10524196/load-gui-from-a-glade-with-gtksourceview-in-pygobject. But it 
> seems that the examples written in C can call gtk_builder_add_from_file() without any preparation. Why? Is 
> there a invisible init operation involved? I think such an init which registers new GObject types like 
> GtkSourceView and related types is necessary when builder is used. But GtkSourceView library has no init 
> function (gtk3 has one, and of course I call it, but I think it can and will not init gtksourceview lib.) I 
> know there is another mailing list closer related to gtksourceview available, but there seems to be no 
> activity for months. And this is not really a gtksourceview question, but more about general builder and 
> unknown gobject types.

This sounds similar to the problems I've recently run into with wxPython 
(Python wrappers for wxWidgets, which has a GTK implementation).

Basically, GTK assumes that its libraries are loaded into the global 
symbol namespace.  I'm guessing that Nim is probably loading them into a 
local namespace (RTLD_LOCAL) and thus when GtkBuilder tries to load 
GtkSourceView, it can't find it.  Does Nim let you load the libraries into 
the global namespace instead?  That may be one possible way to work around 
this, assuming that's what you're seeing.

Scott