add event system and use it to propagate to print traces

src/lib/eventsystem/EventHandlerBase.h

@@ -0,0 +1,25 @@
+#ifndef EVENT_HANDLER_BASE_H
+#define EVENT_HANDLER_BASE_H
+
+#include <memory>
+
+class Event;
+class EventManager;
+
+class EventHandlerBase
+{
+private:
+	static unsigned int s_nextId;
+
+public:
+	EventHandlerBase();
+	virtual ~EventHandlerBase() = default;
+	virtual void handleBaseEvent(std::shared_ptr<const Event> event) = 0;
+
+private:
+	const unsigned int m_id;
+
+	friend EventManager;
+};
+
+#endif   // EVENT_HANDLER_BASE_H