StateEvent; EventContent::SimpleContent; event types refactoring

* StateEvent<> is a new class template for all state events. It provides a uniform interface to the state content, as well as a means to serialize the content back to JSON. In addition, StateEvent now parses the "prev_content" JSON object, so one can refer to the previous state now (a notable step to proper reflection of state changes in the displayed timeline in clients).
* EventContent::SimpleContent, together with StateEvent<>, forms a generalisation for simple state events, such as room name, topic, aliases etc. that boil down to a single key-value pair. DECLARE_SIMPLE_STATE_EVENT is a macro defined to streamline creation of events based on SimpleContent, providing API back-compatibility for events defined so far. As a result, a very concise simplestateevents.h replaces all those room*event.* files.
* Event/RoomEvent::fromJson() code is squeezed down to plain type lists passed to makeIfMatches() "chained factory" function template. TypeId is mandatory for an event type to be included into that factory.
* Event::toTimestamp() and Event::toStringList are completely superseded by respective fromJson<>() converters.

1 files changed, 54 insertions, 0 deletions

diff --git a/events/simplestateevents.h b/events/simplestateevents.h
new file mode 100644
index 00000000..d5841bdc
--- /dev/null
+++ b/events/simplestateevents.h
@@ -0,0 +1,54 @@
+/******************************************************************************
+ * Copyright (C) 2017 Kitsune Ral <kitsune-ral@users.sf.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#pragma once
+
+#include "event.h"
+
+#include "eventcontent.h"
+
+namespace QMatrixClient
+{
+#define DECLARE_SIMPLE_STATE_EVENT(_Name, _TypeId, _EnumType, _ContentType, _ContentKey) \
+    class _Name \
+        : public StateEvent<EventContent::SimpleContent<_ContentType>> \
+    { \
+        public: \
+            static constexpr const char* TypeId = _TypeId; \
+            explicit _Name(const QJsonObject& obj) \
+                : StateEvent(_EnumType, obj, #_ContentKey) \
+            { } \
+            template <typename T> \
+            explicit _Name(T&& value) \
+                : StateEvent(_EnumType, #_ContentKey, \
+                             std::forward<T>(value)) \
+            { } \
+            _ContentType _ContentKey() const { return content().value; } \
+    };
+
+    DECLARE_SIMPLE_STATE_EVENT(RoomNameEvent, "m.room.name",
+                               Event::Type::RoomName, QString, name)
+    DECLARE_SIMPLE_STATE_EVENT(RoomAliasesEvent, "m.room.aliases",
+                               Event::Type::RoomAliases, QStringList, aliases)
+    DECLARE_SIMPLE_STATE_EVENT(RoomCanonicalAliasEvent, "m.room.canonical_alias",
+                               Event::Type::RoomCanonicalAlias, QString, alias)
+    DECLARE_SIMPLE_STATE_EVENT(RoomTopicEvent, "m.room.topic",
+                               Event::Type::RoomTopic, QString, topic)
+    DECLARE_SIMPLE_STATE_EVENT(EncryptionEvent, "m.room.encryption",
+                               Event::Type::RoomEncryption, QString, algorithm)
+} // namespace QMatrixClient