feat: show live battery charge by default

src/session.rs

@@ -170,6 +170,8 @@ pub struct EditorSession {
     pending_completion: bool,
     hover_owner: Option<String>,
     diff_workers: BTreeMap<usize, DiffWorker>,
+    battery: Option<crate::battery::Battery>,
+    battery_enabled: bool,
 }
 
 impl EditorSession {
@@ -267,8 +269,11 @@ impl EditorSession {
             pending_completion: false,
             hover_owner: None,
             diff_workers: BTreeMap::new(),
+            battery: None,
+            battery_enabled: false,
         };
         session.synchronize_documents();
+        session.poll_battery();
         Ok(session)
     }
 
@@ -926,9 +931,46 @@ impl EditorSession {
         Ok(changed)
     }
 
+    fn poll_battery(&mut self) -> bool {
+        let enabled = self.editor.label("battery").is_empty()
+            && [
+                self.editor.top_bar_config(),
+                self.editor.bottom_bar_config(),
+            ]
+            .into_iter()
+            .any(|bar| {
+                bar.left
+                    .iter()
+                    .chain(&bar.center)
+                    .chain(&bar.right)
+                    .any(|name| name == "battery")
+            });
+        let mut changed = false;
+        if enabled != self.battery_enabled {
+            self.battery_enabled = enabled;
+            // Unit sessions do not read external hardware; provider and renderer checks inject data.
+            #[cfg(not(test))]
+            {
+                self.battery = if enabled {
+                    crate::battery::Battery::start().ok()
+                } else {
+                    None
+                };
+            }
+            if !enabled {
+                changed |= self.editor.set_battery_charge(None);
+            }
+        }
+        if let Some(charge) = self.battery.as_mut().and_then(|battery| battery.poll()) {
+            changed |= self.editor.set_battery_charge(charge);
+        }
+        changed
+    }
+
     /// Drains ready plugin work without waiting for command or server responses.
     pub fn poll(&mut self) -> bool {
         let mut changed = self.synchronize_documents();
+        changed |= self.poll_battery();
         changed |= self.poll_diff();
         for update in self.lsp.poll() {
             match self.apply_update("core", update) {