add tray icons

include/widgets/tray.hpp

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <gtkmm/box.h>
+#include <gtkmm/button.h>
+#include <gtkmm/gestureclick.h>
+#include <gtkmm/picture.h>
+#include <gtkmm/image.h>
+
+#include <map>
+#include <memory>
+#include <string>
+
+#include "services/tray.hpp"
+
+class TrayIconWidget : public Gtk::Button
+{
+  public:
+    TrayIconWidget(TrayService &service, std::string id);
+
+    void update(const TrayService::Item &item);
+
+  private:
+    TrayService &m_service;
+    std::string m_id;
+    Gtk::Box m_container;
+    Gtk::Picture m_picture;
+    Gtk::Image m_image;
+    Glib::RefPtr<Gtk::GestureClick> m_secondaryGesture;
+
+    void on_primary_clicked();
+    void on_secondary_released(int n_press, double x, double y);
+};
+
+class TrayWidget : public Gtk::Box
+{
+  public:
+    explicit TrayWidget(TrayService &service);
+    ~TrayWidget() override;
+
+  private:
+    TrayService &m_service;
+    std::map<std::string, std::unique_ptr<TrayIconWidget>> m_icons;
+
+    sigc::connection m_addConnection;
+    sigc::connection m_removeConnection;
+    sigc::connection m_updateConnection;
+
+    void on_item_added(const TrayService::Item &item);
+    void on_item_removed(const std::string &id);
+    void on_item_updated(const TrayService::Item &item);
+
+    void rebuild_existing();
+};