Re: [java-gnome-hackers] GtkCellRendererCombo - help appreciated

[Stefan P. <st...@pr...>]

Hi all,

I was revisiting my attempts to implement a CellRendererCombo.
This time I was trying to implement a "DataColumnTreeModel" to give the
CellRendererCombo a column to pick its model from.

public final class DataColumnTreeModel extends DataColumn {
    public DataColumnTreeModel() {
        super(TreeModel.class);
    }
}

I ran into the problem that there is no mapping from TreeModel to a
GType:

org.freedesktop.bindings.FatalError: Don't know how to map
org.gnome.gtk.TreeModel into a GType

So I tried modifying src/jni/bindings_java_type.[c|h] to add some
mappings:

	} else if (g_str_equal(fqcn, "org.gnome.gtk.TreeStore")) {
		return GTK_TYPE_TREE_STORE;
	} else if (g_str_equal(fqcn, "org.gnome.gtk.ListStore")) {
		return GTK_TYPE_LIST_STORE;
	} else if (g_str_equal(fqcn, "org.gnome.gtk.TreeModel")) {
		return GTK_TYPE_TREE_MODEL;

While this got me a bit further, I now seem to have problems with an
assertion in the native GTK code:

org.gnome.glib.FatalError: Gtk-CRITICAL
gtk_cell_renderer_combo_set_property: assertion `GTK_IS_TREE_MODEL
(object)' failed

which propably leads to the line in gtk/gtktreemodel.h
#define GTK_IS_TREE_MODEL(obj)  (G_TYPE_CHECK_INSTANCE_TYPE ((obj),
GTK_TYPE_TREE_MODEL))

So from my understanding GTK has problems identifying e.g. a
org.gnome.gtk.ListStore (which is an implementation of the abstract
org.gnome.gtk.TreeModel) as of being of a native GtkTreeModel.
Correct?

Am Mittwoch, den 14.05.2008, 15:22 +1000 schrieb Andrew Cowie:
> It _might_ be the same class of problem that we recently ran into with
> GValues holding enums: for some reason GValue gets grumpy when asked to
> hold abstract types. See 'textview' revno 508.

Possibly. Honestly I feel a bit overwhelmed by the whole Plumbing,
GValue, GType and generally deep and dirty mapping stuff.

> [..]
> What a pain. I hate GValues.
> 
> In fact, I'd be happy if they went away entirely. That would mean making
> GObject.setProperty(), GtkTreeView.setValue()  and anything else that
> uses GValue have a native overload for every type combination [in a
> hand written Override]. That *is* doable, but at present we have all
> those code paths concentrated through the Value code paths.
> 
> Well, whatever. Something for the future.

So that means there is currently no simple workaround to get the
CellRendererCombo working?

Regards,
 Stefan