add event system and use it to propagate to print traces

src/lib/eventsystem/EventManager.cpp

@@ -0,0 +1,123 @@
+#include "EventManager.h"
+
+#include <set>
+
+#include "EventHandlerBase.h"
+
+std::shared_ptr<EventManager> EventManager::getInstance()
+{
+	if (!s_instance)
+	{
+		s_instance = std::shared_ptr<EventManager>(new EventManager());
+	}
+	return s_instance;
+}
+
+void EventManager::destroyInstance()
+{
+	if (s_instance)
+	{
+		s_instance.reset();
+	}
+}
+
+std::shared_ptr<EventManager> EventManager::s_instance = std::shared_ptr<EventManager>();
+
+void EventManager::registerEventHandler(EventHandlerBase *eventHandler)
+{
+	std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+	m_eventHandlers[eventHandler->m_id] = eventHandler;
+}
+
+void EventManager::unregisterEventHandler(EventHandlerBase *eventHandler)
+{
+	std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+	m_eventHandlers.erase(eventHandler->m_id);
+}
+
+void EventManager::sendEventImmediately(std::shared_ptr<Event> event)
+{
+	if (event)
+	{
+		std::set<unsigned int> eventHandlerIds;
+		{
+			std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+			for (auto it : m_eventHandlers)
+			{
+				eventHandlerIds.insert(it.first);
+			}
+		}
+
+		for (unsigned int id : eventHandlerIds)
+		{
+			// this is necessary to allow HandleBaseEvent() to remove event handlers without causing a crash
+			EventHandlerBase *eventHandler = nullptr;
+			{
+				std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+				auto it = m_eventHandlers.find(id);
+				if (it != m_eventHandlers.end())
+				{
+					eventHandler = it->second;
+				}
+			}
+			if (eventHandler)
+			{
+				eventHandler->handleBaseEvent(event);
+			}
+		}
+	}
+}
+
+void EventManager::addEvent(std::shared_ptr<Event> event)
+{
+	if (event)
+	{
+		std::scoped_lock<std::mutex> lock(m_eventsMutex);
+		m_events.push_back(event);
+	}
+}
+
+void EventManager::processEvents()
+{
+	std::vector<std::shared_ptr<Event>> events;
+	{
+		std::scoped_lock<std::mutex> lock(m_eventsMutex);
+		events = m_events;
+		m_events.clear();
+	}
+
+	std::set<unsigned int> eventHandlerIds;
+	{
+		std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+		for (auto it : m_eventHandlers)
+		{
+			eventHandlerIds.insert(it.first);
+		}
+	}
+
+	for (std::shared_ptr<Event> event : events)
+	{
+		for (unsigned int id : eventHandlerIds)
+		{
+			// this is necessary to allow HandleBaseEvent() to remove event handlers without causing a crash
+			EventHandlerBase *eventHandler = nullptr;
+			{
+				std::scoped_lock<std::mutex> lock(m_eventHandlersMutex);
+				auto it = m_eventHandlers.find(id);
+				if (it != m_eventHandlers.end())
+				{
+					eventHandler = it->second;
+				}
+			}
+			if (eventHandler)
+			{
+				eventHandler->handleBaseEvent(event);
+			}
+		}
+	}
+}
+
+bool EventManager::hasEvents() const
+{
+	return !m_events.empty();
+}