app: wire audio device hot-swap on change

src/tuimble/app.py

@@ -14,7 +14,7 @@ from textual.message import Message
 from textual.reactive import reactive
 from textual.widgets import Footer, Header, Input, RichLog, Static
 
-from tuimble.audio import AudioPipeline
+from tuimble.audio import AudioPipeline, DeviceMonitor
 from tuimble.client import Channel, MumbleClient, User
 from tuimble.config import Config, load_config
 from tuimble.ptt import KittyPtt, TogglePtt, detect_backend
@@ -91,6 +91,12 @@ class ServerStateChanged(Message):
     pass
 
 
+class AudioDeviceChanged(Message):
+    """Audio device list changed (hot-swap detected)."""
+
+    pass
+
+
 class ChannelSelected(Message):
     """User selected a channel to join."""
 
@@ -381,12 +387,12 @@ class TuimbleApp(App):
     }
     #chatlog {
         height: 1fr;
+        border-bottom: solid #292e42;
         scrollbar-size: 1 1;
     }
     #input {
         height: 3;
-        border-top: solid #292e42;
-        padding: 0 1 0 0;
+        border: none;
     }
     #status {
         dock: bottom;
@@ -425,6 +431,7 @@ class TuimbleApp(App):
         )
         self._audio.input_gain = acfg.input_gain
         self._audio.output_gain = acfg.output_gain
+        self._device_monitor = DeviceMonitor(self._on_device_change)
         self._pending_reload: Config | None = None
         self._tree_refresh_timer = None
         self._reconnect = ReconnectManager(
@@ -581,6 +588,7 @@ class TuimbleApp(App):
         self._start_audio()
 
     def on_server_disconnected(self, _msg: ServerDisconnected) -> None:
+        self._device_monitor.stop()
         self._audio.stop()
 
         status = self.query_one("#status", StatusBar)
@@ -643,11 +651,52 @@ class TuimbleApp(App):
 
     # -- audio ---------------------------------------------------------------
 
+    def _on_device_change(self) -> None:
+        """Called from DeviceMonitor thread on device list change."""
+        self.call_from_thread(self.post_message, AudioDeviceChanged())
+
+    @staticmethod
+    def _validate_device(device_id: int | None, kind: str) -> int | None:
+        """Return *device_id* if still valid, else ``None`` (system default)."""
+        if device_id is None:
+            return None
+        try:
+            import sounddevice as sd
+
+            sd.query_devices(device_id, kind)
+            return device_id
+        except Exception:
+            return None
+
+    def on_audio_device_changed(self, _msg: AudioDeviceChanged) -> None:
+        """Rebuild the audio pipeline when devices change."""
+        chatlog = self.query_one("#chatlog", ChatLog)
+        chatlog.write("[dim]audio device change detected[/dim]")
+
+        self._audio.stop()
+
+        acfg = self._config.audio
+        inp = self._validate_device(acfg.input_device, "input")
+        out = self._validate_device(acfg.output_device, "output")
+
+        self._audio = AudioPipeline(
+            sample_rate=acfg.sample_rate,
+            frame_size=acfg.frame_size,
+            input_device=inp,
+            output_device=out,
+        )
+        self._audio.input_gain = acfg.input_gain
+        self._audio.output_gain = acfg.output_gain
+
+        if self._client.connected:
+            self._start_audio()
+
     def _start_audio(self) -> None:
         """Start audio pipeline; log error if hardware unavailable."""
         chatlog = self.query_one("#chatlog", ChatLog)
         try:
             self._audio.start()
+            self._device_monitor.start()
             chatlog.write("[dim]audio pipeline started[/dim]")
             self._audio_send_loop()
         except Exception as exc:
@@ -918,6 +967,7 @@ class TuimbleApp(App):
     def action_quit(self) -> None:
         self._intentional_disconnect = True
         self._cancel_reconnect()
+        self._device_monitor.stop()
         self._audio.stop()
         self._client.set_dispatcher(None)
         self._client.disconnect()