Re: Tab behavior in GtkClutter

[Canek PelÃez ValdÃs <caneko gmail com>]

On Sat, Dec 8, 2012 at 1:28 AM, Canek PelÃez ValdÃs <caneko gmail com> wrote:
> Hi; I'm using gtk-clutter in the (AFAIU) normal way:
>
> GtkWindow -> GtkClutterEmbed -> ClutterStage (comes with
> GtkClutterEmbed) -> GtkClutterActor -> GtkWidget
>
> I use the stage to animate the widgets; that part seems to be working
> correctly. However, in the innermost widget and its children the tab
> behavior doesn't seem to work as in a normal Gtk+ application. In my
> Clutter-Gtk application, if one of the widgets inside the
> GtkClutterActor has the focus and I press Tab, then it loses the focus
> and no other widget gets it. In a normal Gtk+ application, the next
> focusable widget grabs the focus. I attach a little Vala example
> showing the problem (Vala 0.18, Gtk+ 3.6.2, Clutter 1.12.2,
> Clutter-Gtk 1.4.0).
>
> Does anyone know how do I fix this so my Clutter-Gtk application has
> the same tab behavior as a normal Gtk+ application?
>
> Thanks in advance.
>
> // Compile with valac --pkg gtk+-3.0 --pkg clutter-gtk-1.0 tab-example.vala
> using Gtk;
>
> public class TabExample {
>
>         private Window window;
>
>         public TabExample() {
>                 window = new Window();
>                 window.title = "Tab Example";
>                 window.delete_event.connect(() => {
>                                 Gtk.main_quit();
>                                 return true;
>                         });
>
>                 var embed = new GtkClutter.Embed();
>                 embed.expand = true;
>                 window.add(embed);
>
>                 var stage = embed.get_stage();
>
>                 var grid = new Grid();
>                 grid.expand = true;
>                 var label = new Label("Input 1:");
>                 grid.attach(label, 0, 0, 1, 1);
>                 var entry = new Entry();
>                 entry.width_chars = 40;
>                 grid.attach(entry, 1, 0, 1, 1);
>                 label = new Label("Input 2:");
>                 grid.attach(label, 0, 1, 1, 1);
>                 entry = new Entry();
>                 entry.width_chars = 40;
>                 grid.attach(entry, 1, 1, 1, 1);
>                 grid.column_spacing = 6;
>                 grid.row_spacing = 6;
>                 grid.margin_left = 6;
>                 grid.margin_right = 6;
>                 grid.margin_top = 6;
>                 grid.margin_bottom = 6;
>                 grid.show_all();
>                 var actor = new GtkClutter.Actor.with_contents(grid);
>                 stage.add_child(actor);
>         }
>
>         public void show() {
>                 window.set_default_size(600, 100);
>                 window.show_all();
>         }
>
>         public static int main(string[] args) {
>                 if (GtkClutter.init(ref args) != Clutter.InitError.SUCCESS) {
>                         GLib.warning("Could not initialize GtkClutter");
>                         return 1;
>                 }
>
>                 var te = new TabExample();
>                 te.show();
>
>                 Gtk.main();
>
>                 return 0;
>         }
> }

I'm answering myself, since I got no response. The solution (it seems)
is to extend GtkClutter.Embed and override all keyboard handling, so
the extended class looks to Gtk+ like a dumb container. The idea was
first implemented (AFAICS) in gnome-boxes:

http://git.gnome.org/browse/gnome-boxes/tree/src/clutter-widget.vala

With this, all key handling works like in a regular Gtk+ application,
which is exactly what I needed.

Regards.
-- 
Canek PelÃez ValdÃs
Posgrado en Ciencia e IngenierÃa de la ComputaciÃn
Universidad Nacional AutÃnoma de MÃxico