* Copyright (C) 2014 - 2016 by Ivan Cukic <ivan.cukic@kde.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License or (at your option) version 3 or any later version
* accepted by the membership of KDE e.V. (or its successor approved
* by the membership of KDE e.V.), which shall act as a proxy
* defined in Section 14 of version 3 of the license.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef UTILS_CONTINUE_WITH_H
#define UTILS_CONTINUE_WITH_H
#include <QFuture>
#include <QFutureWatcher>
#include <QDebug>
#include "utils/optional_view.h"
#ifdef ENABLE_QJSVALUE_CONTINUATION
#include <QJSValue>
#endif
namespace kamd {
namespace utils {
namespace detail {
#ifdef ENABLE_QJSVALUE_CONTINUATION
inline void test_continuation(const QJSValue &continuation)
{
if (!continuation.isCallable()) {
qWarning() << "Passed handler is not callable: " << continuation.toString();
}
}
template <typename _ReturnType>
inline void pass_value(const QFuture<_ReturnType> &future,
QJSValue continuation)
{
auto result = continuation.call({ future.result() });
if (result.isError()) {
qWarning() << "Handler returned this error: " << result.toString();
}
}
inline void pass_value(const QFuture<void> &future, QJSValue continuation)
{
Q_UNUSED(future);
auto result = continuation.call({});
if (result.isError()) {
qWarning() << "Handler returned this error: " << result.toString();
}
}
#endif
template <typename _Continuation>
inline void test_continuation(_Continuation &&continuation)
{
Q_UNUSED(continuation);
}
template <typename _ReturnType, typename _Continuation>
inline void pass_value(const QFuture<_ReturnType> &future,
_Continuation &&continuation)
{
using namespace kamd::utils;
continuation(future.resultCount() > 0
? make_optional_view(future.result())
: none());
}
template <typename _Continuation>
inline void pass_value(_Continuation &&continuation)
{
continuation();
}
}
template <typename _ReturnType, typename _Continuation>
inline void continue_with(const QFuture<_ReturnType> &future,
_Continuation &&continuation)
{
detail::test_continuation(continuation);
auto watcher = new QFutureWatcher<_ReturnType>();
QObject::connect(watcher, &QFutureWatcherBase::finished, [=]() mutable {
detail::pass_value(future, continuation);
});
watcher->setFuture(future);
}
}
}
#endif
