Practical Template Programming - Learn C++ for Game Development - page 199

void EventManager::SendEventToHandler(EventID eventId, EventHandler& eventHandler)
{
EventMapIterator result = m_eventMap.find(eventId);
if (result != m_eventMap.end())
{
assert(result->second);
if (result->second)
{
result->second->SendToHandler(eventHandler);
}
}
}
The destructor for the EventManager class is also interesting. It is responsible for cleaning up
the Event objects in the unordered_map . As they were created using the new keyword, they must
be destroyed using the delete keyword (I cover this in detail in Chapter 24). The EventManager
destructor is given in Listing 21-13.
Listing 21-13. The EventManager Destructor
EventManager::~EventManager()
{
for (EventMapIterator iter = m_eventMap.begin(); iter != m_eventMap.end(); ++iter)
{
Event* pEvent = iter->second;
if (pEvent)
{
delete pEvent;
iter->second = nullptr;
}
}
m_eventMap.clear();
}
The destructor iterates over the m_eventMap variable, deletes each Event , and sets the second
member on the iterator to be nullptr .
Now I can show you the public friend functions that wrap the EventManager private methods.
Listing 21-14 shows the code for the SendEvent friend function.
Listing 21-14. The SendEvent friend Function
inline void SendEvent(EventID eventId)
{
EventManager* pEventManager = EventManager::GetSingletonPtr();
assert(pEventManager);
if (pEventManager)
{
pEventManager->SendEvent(eventId);
}
}