Re: How to use Gio::DBus::Connection::signal_subscribe?

[Christof Meerwald <cmeerw cmeerw org>]

On Sun, 20 Sep 2015 11:56:29 -0400, Nicolas Jäger wrote:
> guint Gio::DBus::Connection::signal_subscribe         (       const SlotSignal&       slot,
>               const Glib::ustring&    sender = Glib::ustring(),
>               const Glib::ustring&    interface_name = Glib::ustring(),
>               const Glib::ustring&    member = Glib::ustring(),
>               const Glib::ustring&    object_path = Glib::ustring(),
>               const Glib::ustring&    arg0 = Glib::ustring(),
>               SignalFlags     flags = Gio::DBus::SIGNAL_FLAGS_NONE 
>       )       
>
> I just wake up, sender is a reference, not a pointer. Maybe you are trying to dereferencing a null
> pointer...

Well yes, sure - the string constructor (that converts from a const
char *) is complaining about the null pointer.

> have you try to do :
>
>   Glib::ustring sender;
>
>   ...->signal_subscribe( ..., sender, ... );
>
>
> or just let the paramater not set,
>
>   ...->signal_subscribe( ..., , ... );

but both of these options would map to empty strings (and therefore
don't work).

Looking at
https://developer.gnome.org/gio/unstable/GDBusConnection.html#g-dbus-connection-signal-subscribe
it should map to a NULL pointer in the C interface, but that doesn't
seem to be possible.


Christof

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