fix(keyboard): panic when layout update channel lags behind (#869)

Fixes #866

src/clients/compositor/hyprland.rs

@@ -25,7 +25,7 @@ pub struct Client {
 impl Client {
     pub(crate) fn new() -> Self {
         let (workspace_tx, workspace_rx) = channel(16);
-        let (keyboard_layout_tx, keyboard_layout_rx) = channel(4);
+        let (keyboard_layout_tx, keyboard_layout_rx) = channel(16);
 
         let instance = Self {
             workspace_tx,

src/clients/compositor/sway.rs

@@ -166,7 +166,7 @@ impl KeyboardLayoutClient for Client {
     }
 
     fn subscribe(&self) -> Receiver<KeyboardLayoutUpdate> {
-        let (tx, rx) = channel(4);
+        let (tx, rx) = channel(16);
 
         let client = self.connection().clone();
 

src/modules/keyboard.rs

@@ -210,10 +210,21 @@ impl Module<gtk::Box> for KeyboardModule {
 
                 trace!("Set up keyboard_layout subscription");
 
-                while let Ok(payload) = srx.recv().await {
+                loop {
+                    match srx.recv().await {
+                        Ok(payload) => {
                             debug!("Received update: {payload:?}");
                             module_update!(tx, KeyboardUpdate::Layout(payload));
                         }
+                        Err(tokio::sync::broadcast::error::RecvError::Lagged(count)) => {
+                            tracing::warn!("Channel lagged behind by {count}, this may result in unexpected or broken behaviour");
+                        }
+                        Err(err) => {
+                            tracing::error!("{err:?}");
+                            break;
+                        }
+                    };
+                }
             });
         }