[FEATURE REQUEST] Receive D-Bus signals as stream #1820
Description
Currently, gio::DBusConnection only offers signal_subscribe and signal_unsubscribe to receive D-Bus signals, which isn't that convenient, and I find myself defining some abstractions around this in every Rust project, to handle signal lifetime more conveniently and on top of that to receive signal emissions as a stream instead of dealing with callbacks, e.g.
#[derive(Debug)]
pub struct SignalSubscription {
bus: WeakRef<gio::DBusConnection>,
id: Option<SignalSubscriptionId>,
}
impl SignalSubscription {
fn new(bus: &gio::DBusConnection, id: SignalSubscriptionId) -> Self {
Self {
bus: bus.downgrade(),
id: Some(id),
}
}
}
impl Drop for SignalSubscription {
fn drop(&mut self) {
if let Some(connection) = self.bus.upgrade()
&& let Some(id) = self.id.take()
{
connection.signal_unsubscribe(id);
}
}
}and then something like
/// Receive emissions of a D-Bus signal as stream.
fn receive_signal<S: AsRef<str>, T: FromVariant + 'static + Send>(
&self,
sender: Option<&str>,
interface_name: Option<&str>,
member: Option<&str>,
object_path: Option<&str>,
arg0: Option<S>,
flags: DBusSignalFlags,
) -> impl Stream<Item = T>;implemented on top of mpsc::channel and the above SignalSubscription to create a stream from signal emissions, with the lifetime of the signal subscription coupled to the lifetime of the stream, and with automatic variant conversion of signal parameters.
Would this be a reasonable and desired extension to gio::DBusConnection? If so, I'll prepare a pull request, but I can also understand if it's not something you'd like to maintain; in this I'll just keep it in my local utility library.