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/******************************************************************************
* Copyright (C) 2015 Felix Rohrbach <kde@fxrh.de>
*
* 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
*/
#ifndef QMATRIXCLIENT_EVENT_H
#define QMATRIXCLIENT_EVENT_H
#include <algorithm>
#include <QtCore/QString>
#include <QtCore/QDateTime>
#include <QtCore/QJsonObject>
#include <QtCore/QVector>
class QJsonArray;
namespace QMatrixClient
{
enum class EventType
{
RoomMessage, RoomName, RoomAliases, RoomCanonicalAlias,
RoomMember, RoomTopic, Typing, Receipt, Unknown
};
class Event
{
public:
explicit Event(EventType type);
Event(Event&) = delete;
virtual ~Event();
EventType type() const;
QString id() const;
QDateTime timestamp() const;
QString roomId() const;
QString senderId() const;
// only for debug purposes!
QString originalJson() const;
static Event* fromJson(const QJsonObject& obj);
protected:
bool parseJson(const QJsonObject& obj);
private:
class Private;
Private* d;
};
using Events = QVector<Event*>;
Events eventsFromJson(const QJsonArray& json);
/**
* @brief Lookup a value by a key in a varargs list
*
* The below overloaded function template takes the value of its first
* argument (selector) as a key and searches for it in the key-value map
* passed in a varargs list (every next pair of arguments forms a key-value
* pair). If a match is found, the respective value is returned; otherwise,
* the last value (fallback) is returned.
*
* All options should be of the same type or implicitly castable to the
* type of the first option. Note that pointers to methods of different
* classes are of different object types, in particular.
*
* Below is an example of usage to select a parser depending on contents of
* a JSON object:
* {@code
* auto parser = lookup(obj.value["type"].toString(),
* "type1", fn1,
* "type2", fn2,
* fallbackFn);
* parser(obj);
* }
*
* The implementation is based on tail recursion; every recursion step
* removes 2 arguments (match and option). There's no selector value for the
* fallback option (the last one); therefore, the total number of lookup()
* arguments should be even: selector + n key-value pairs + fallback
*
* @note Beware of calling lookup() with a <code>const char*</code> selector
* (the first parameter) - most likely it won't do what you expect because
* of shallow comparison.
*/
template <typename ValueT, typename SelectorT, typename KeyT, typename... Ts>
ValueT lookup(SelectorT selector, KeyT key, ValueT value, Ts... remainingMapping)
{
if( selector == key )
return value;
// Drop the failed key-value pair and recurse with 2 arguments less.
return lookup(selector, remainingMapping...);
}
template <typename SelectorT, typename ValueT>
ValueT lookup(SelectorT/*unused*/, ValueT fallback)
{
return fallback;
}
}
#endif // QMATRIXCLIENT_EVENT_H
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