Event types system remade to be extensible

There were two common points that had to be updated every time a new event is introduced:
the EventType enumeration and one of 3 doMakeEvent<> specialisations. The new code
has a template class, EventFactory<>, that uses a list of static factory methods
to create events instead of typelists used in doMakeEvent<>(); the EventType enumeration
is replaced with a namespace populated with constants as necessary.

In general, EventType is considered a deprecated mechanism altogether; instead, a set
of facilities is provided: is<>() to check if an event has a certain type (to replace
comparison against an EventType value) and visit<>() to execute actions based on
the event type (replacing switch statements over EventType values).

Closes #129.

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/events/directchatevent.h b/lib/events/directchatevent.h
index bd8f2d35..1d366721 100644
--- a/lib/events/directchatevent.h
+++ b/lib/events/directchatevent.h
@@ -25,10 +25,13 @@ namespace QMatrixClient
     class DirectChatEvent : public Event
     {
         public:
-            explicit DirectChatEvent(const QJsonObject& obj);
+            DEFINE_EVENT_TYPEID("m.direct", DirectChatEvent)
 
-            QMultiHash<QString, QString> usersToDirectChats() const;
+            explicit DirectChatEvent(const QJsonObject& obj)
+                : Event(typeId(), obj)
+            { }
 
-            static constexpr const char* typeId() { return "m.direct"; }
+            QMultiHash<QString, QString> usersToDirectChats() const;
     };
+    DEFINE_EVENTTYPE_ALIAS(DirectChat, DirectChatEvent)
 }