Adding css reloader

include/client.hpp

@@ -7,6 +7,7 @@
 
 #include "bar.hpp"
 #include "config.hpp"
+#include "util/css_reload_helper.hpp"
 #include "util/portal.hpp"
 
 struct zwlr_layer_shell_v1;
@@ -55,6 +56,8 @@ class Client {
   Glib::RefPtr<Gtk::CssProvider> css_provider_;
   std::unique_ptr<Portal> portal;
   std::list<struct waybar_output> outputs_;
+  std::unique_ptr<CssReloadHelper> m_cssReloadHelper;
+  std::string m_cssFile;
 };
 
 }  // namespace waybar

include/util/css_reload_helper.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <atomic>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <vector>
+
+struct pollfd;
+
+namespace waybar {
+class CssReloadHelper {
+ public:
+  CssReloadHelper(std::string cssFile, std::function<void()> callback);
+
+  ~CssReloadHelper();
+
+  virtual void monitorChanges();
+
+  void stop();
+
+ protected:
+  std::vector<std::string> parseImports(const std::string& cssFile);
+
+  void parseImports(const std::string& cssFile,
+                           std::unordered_map<std::string, bool>& imports);
+
+
+  void watchFiles(const std::vector<std::string>& files);
+
+  bool handleInotifyEvents(int fd);
+
+  bool watch(int inotifyFd, pollfd * pollFd);
+
+  virtual std::string getFileContents(const std::string& filename);
+
+  virtual std::string findPath(const std::string& filename);
+
+ private:
+  std::string m_cssFile;
+  std::function<void()> m_callback;
+  std::atomic<bool> m_running = false;
+  std::thread m_thread;
+  std::mutex m_mutex;
+  std::condition_variable m_cv;
+};
+}  // namespace waybar