dbus: Add power-daemon hotplug handling

src/dbus/mod.rs

@@ -0,0 +1,66 @@
+use crate::state::{BackendData, State};
+use anyhow::{Context, Result};
+use calloop::{InsertError, LoopHandle, RegistrationToken};
+
+mod power;
+
+pub fn init(evlh: &LoopHandle<'static, State>) -> Result<Vec<RegistrationToken>> {
+    let mut tokens = Vec::new();
+
+    match power::init() {
+        Ok(power_daemon) => {
+            let (tx, rx) = calloop::channel::channel();
+
+            let token = evlh
+                .insert_source(rx, |event, _, state| match event {
+                    calloop::channel::Event::Msg(_) => {
+                        let nodes = match &mut state.backend {
+                            BackendData::Kms(kms) => {
+                                kms.devices.keys().cloned().collect::<Vec<_>>()
+                            }
+                            _ => Vec::new(),
+                        };
+                        for node in nodes {
+                            if let Err(err) = state.device_changed(node.dev_id()) {
+                                tracing::error!(?err, "Failed to update drm device {}.", node);
+                            }
+                        }
+                        ()
+                    }
+                    calloop::channel::Event::Closed => (),
+                })
+                .map_err(|InsertError { error, .. }| error)
+                .with_context(|| "Failed to add channel to event_loop")?;
+
+            // start helper thread
+            let result = std::thread::Builder::new()
+                .name("system76-power-hotplug".to_string())
+                .spawn(move || {
+                    if let Ok(mut msg_iter) = power_daemon.receive_hot_plug_detect() {
+                        while let Some(msg) = msg_iter.next() {
+                            if tx.send(msg).is_err() {
+                                break;
+                            }
+                        }
+                    }
+                })
+                .with_context(|| "Failed to start helper thread");
+
+            match result {
+                Ok(_handle) => {
+                    tokens.push(token);
+                    // detach thread
+                }
+                Err(err) => {
+                    evlh.remove(token);
+                    return Err(err);
+                }
+            }
+        }
+        Err(err) => {
+            tracing::info!(?err, "Failed to connect to com.system76.PowerDaemon");
+        }
+    };
+
+    Ok(tokens)
+}