Re: Signals that do not get emitted

[Richard Shann <richard shann virgin net>]

I have the solution, and it is potentially of general interest. It seems
that the GtkPrintOperation widget is interacting with the (Unix) SIGUSR1
signal, which our program started using a while ago to do the client
thing. Dropping the (unix) signal handler for that signal made the
(glib) signals on the GtkPrintOperation widget start to work again.
I don't know if that is documented anywhere.

Richard Shann




On Mon, 2011-11-21 at 12:00 +0000, gtk-app-devel-list-request gnome org
wrote:
> Message: 4
> Date: Sun, 20 Nov 2011 16:13:57 +0000
> From: Richard Shann <richard shann virgin net>
> To: gtk-app-devel-list gnome org
> Subject: Signals that do not get emitted
> Message-ID: <1321805637 2172 21 camel debian2 myhost>
> Content-Type: text/plain; charset="UTF-8"
>
> At one time we had the GtkPrintOperation widget working, sending
> begin_print and draw_page signals; now it no longer works - the
> callback
> is never reached - and I wonder if anyone has some idea as to why that
> should be.
> It is not the specific bit of code that creates/launches the widget,
> but
> something more generic (like disabling a class of signals, if such a
> thing is possible). I say this because I only came across it when I
> installed a widget from libevince which uses the GtkPrintOperation and
> that fails to get the callbacks.
> I have built the evince widget as a standalone program (see below) and
> it works. But the same piece of code called from within our (large)
> program does not.
>
> This has been seen in Gtk 2.30.2 and also in Gtk-3 (not sure which
> version).
>
> Any ideas how this can happen? (the project is Denemo, www.denemo.org,
> and the file concerned is print.c).