question: how to create object representing Gtk+ (version 3) interfaces? For example. (let (model (make <GtkTreeModel>))) would fail because GtkTreeModel is an interface, not class derived from GObject. Thanks
question: how to create object representing Gtk+ (version 3) interfaces? For example. (let (model (make <GtkTreeModel>))) would fail because GtkTreeModel is an interface, not class derived from GObject. Thanks
[-- Attachment #1: Type: text/plain, Size: 557 bytes --] Andy Tai schreef op di 14-06-2022 om 11:52 [-0700]: > question: how to create object representing Gtk+ (version 3) > interfaces? For example. > > (let (model (make <GtkTreeModel>))) > > would fail because GtkTreeModel is an interface, not class derived > from GObject. By definition, you cannot instatiate interfaces, but you can instantiate classes derived from GtkTreeModel? Seems like you answered the question yourself? Maybe guile-gi even supports defining an implementation yourself in Scheme with GOOPS ... Greetings, Maxime. [-- Attachment #2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 260 bytes --]
Hi, thanks for the reply. The interface in GObject level does not
necessarily translate as is to GOOPS at guile level...
the context of this question is
(let ((iter (make <GtkTreeIter>))
(model (make <GtkTreeModel>)))
(define selected (tree-selection:get-selected! selection model iter))
get_selected(GtkTreeModel out model, GtkTreeeIter out iter) has two
out parameters, model and iter, but I think GOOPS does type check on
arguments before invoking a method so both parameters must be
initialized to the expected types.
The model parameter normally is instance of a GOBject class
"implementing" the GtkTreeModel interface (at the GOBject level), and
I cannot pass in a concrete GOBject class that implements GtkTreeModel
as GOOPS will reject such calls--GOOPS does not understand "class
implementing an interface" at the GOBject level. So I don't know how
to initialize the model parameter.
On Tue, Jun 14, 2022 at 12:42 PM Maxime Devos <maximedevos@telenet.be> wrote:
>
> Andy Tai schreef op di 14-06-2022 om 11:52 [-0700]:
> > question: how to create object representing Gtk+ (version 3)
> > interfaces? For example.
> >
> > (let (model (make <GtkTreeModel>)))
> >
> > would fail because GtkTreeModel is an interface, not class derived
> > from GObject.
>
> By definition, you cannot instatiate interfaces, but you can
> instantiate classes derived from GtkTreeModel?
> Maybe guile-gi even supports defining an implementation yourself in
> Scheme with GOOPS ...
>
--
Andy Tai, atai@atai.org, Skype: licheng.tai, Line: andy_tai, WeChat: andytai1010
Year 2021 民國110年
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[-- Attachment #1: Type: text/plain, Size: 838 bytes --] Andy Tai schreef op di 14-06-2022 om 21:05 [-0700]: > (let ((iter (make <GtkTreeIter>)) > (model (make <GtkTreeModel>))) > (define selected (tree-selection:get-selected! selection model iter)) > > get_selected(GtkTreeModel out model, GtkTreeeIter out iter) has two > out parameters, model and iter, Looking at <https://spk121.github.io/guile-gi/Function-Parameters-Arity-and-Return-Values.html>, on the Scheme level the output parameters would be converted to return values, so the API would be (receive (selected iter model) (tree-selection:get-selected selection) ; or [do things with iter and iter and model]) Doesn't seem to work though -- looking at (generic-function-methods tree-selection:get-selected), Guile-GI incorrectly doesn't convert it to a return value or something? Greetings, Maxime. [-- Attachment #2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 260 bytes --]