Merge pull request #4941 from sjudin/groups-add-empty-css-class

feat(group): Add .empty class to empty groups

include/group.hpp

@@ -10,7 +10,7 @@
 namespace waybar {
 
 class Group : public AModule {
- sigc::connection reveal_timeout_;
+  sigc::connection reveal_timeout_;
 
  public:
   Group(const std::string&, const std::string&, const Json::Value&, bool);
@@ -28,6 +28,7 @@ class Group : public AModule {
   bool is_first_widget = true;
   bool is_drawer = false;
   bool click_to_reveal = false;
+  bool empty_if_drawer_empty = false;
   int reveal_delay = 0;
   std::string add_class_to_drawer_children;
   bool handleMouseEnter(GdkEventCrossing* const& ev) override;