Hide module if UPower service isn't running

Author: ErikReider

include/modules/upower/upower.hpp

@@ -34,6 +34,10 @@ class UPower : public AModule {
                                  const gchar *object_path, const gchar *interface_name,
                                  const gchar *signal_name, GVariant *parameters,
                                  gpointer user_data);
+  static void upowerAppear(GDBusConnection *conn, const gchar *name, const gchar *name_owner,
+                           gpointer data);
+  static void upowerDisappear(GDBusConnection *connection, const gchar *name, gpointer user_data);
+
   void        removeDevice(const gchar *objectPath);
   void        addDevice(UpDevice *device);
   void        setDisplayDevice();
@@ -67,6 +71,8 @@ class UPower : public AModule {
   UPowerTooltip   *upower_tooltip;
   std::string      lastStatus;
   bool             showAltText;
+  bool             upowerRunning;
+  guint            upowerWatcher_id;
 };
 
 }  // namespace waybar::modules::upower

src/modules/upower/upower.cpp

@@ -68,6 +68,14 @@ UPower::UPower(const std::string& id, const Json::Value& config)
     box_.signal_query_tooltip().connect(sigc::mem_fun(*this, &UPower::show_tooltip_callback));
   }
 
+  upowerWatcher_id = g_bus_watch_name(G_BUS_TYPE_SYSTEM,
+                                      "org.freedesktop.UPower",
+                                      G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
+                                      upowerAppear,
+                                      upowerDisappear,
+                                      this,
+                                      NULL);
+
   GError* error = NULL;
   client = up_client_new_full(NULL, &error);
   if (client == NULL) {
@@ -106,6 +114,7 @@ UPower::~UPower() {
     g_dbus_connection_signal_unsubscribe(login1_connection, login1_id);
     login1_id = 0;
   }
+  g_bus_unwatch_name(upowerWatcher_id);
   removeDevices();
 }
 
@@ -142,6 +151,17 @@ void UPower::prepareForSleep_cb(GDBusConnection* system_bus, const gchar* sender
     }
   }
 }
+void UPower::upowerAppear(GDBusConnection* conn, const gchar* name, const gchar* name_owner,
+                          gpointer data) {
+  UPower* up = static_cast<UPower*>(data);
+  up->upowerRunning = true;
+  up->dp.emit();
+}
+void UPower::upowerDisappear(GDBusConnection* conn, const gchar* name, gpointer data) {
+  UPower* up = static_cast<UPower*>(data);
+  up->upowerRunning = false;
+  up->dp.emit();
+}
 
 void UPower::removeDevice(const gchar* objectPath) {
   std::lock_guard<std::mutex> guard(m_Mutex);
@@ -261,6 +281,14 @@ std::string UPower::timeToString(gint64 time) {
 auto UPower::update() -> void {
   std::lock_guard<std::mutex> guard(m_Mutex);
 
+  // Hide everything if the UPower service is not running
+  if (!upowerRunning) {
+    event_box_.set_visible(false);
+    // Call parent update
+    AModule::update();
+    return;
+  }
+
   UpDeviceKind  kind;
   UpDeviceState state;
   double        percentage;