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, 4 insertions, 6 deletions

diff --git a/lib/events/roomavatarevent.h b/lib/events/roomavatarevent.h
index 0e44ad7c..fe11807c 100644
--- a/lib/events/roomavatarevent.h
+++ b/lib/events/roomavatarevent.h
@@ -20,8 +20,6 @@
 
 #include "event.h"
 
-#include <utility>
-
 #include "eventcontent.h"
 
 namespace QMatrixClient
@@ -33,11 +31,11 @@ namespace QMatrixClient
             // without a thumbnail. But The Spec says there be thumbnails, and
             // we follow The Spec.
         public:
+            DEFINE_EVENT_TYPEID("m.room.avatar", RoomAvatarEvent)
             explicit RoomAvatarEvent(const QJsonObject& obj)
-                : StateEvent(Type::RoomAvatar, obj)
+                : StateEvent(typeId(), obj)
             { }
-
-            static constexpr const char* typeId() { return "m.room.avatar"; }
+            QUrl url() const { return content().url; }
     };
-
+    DEFINE_EVENTTYPE_ALIAS(RoomAvatar, RoomAvatarEvent)
 }  // namespace QMatrixClient