+/*
+ Copyright (C) 2018 Carl Hetherington <cth@carlh.net>
+
+ This file is part of DCP-o-matic.
+
+ DCP-o-matic 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) any later version.
+
+ DCP-o-matic 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 DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#ifndef DCPOMATIC_CHANGE_H
+#define DCPOMATIC_CHANGE_H
+
+#include <boost/noncopyable.hpp>
+
+template <class T>
+class ChangeSignaller : public boost::noncopyable
+{
+public:
+ ChangeSignaller (T* t, int p)
+ : _thing (t)
+ , _property (p)
+ , _done (true)
+ {
+ _thing->signal_change (CHANGE_TYPE_PENDING, _property);
+ }
+
+ ~ChangeSignaller ()
+ {
+ if (_done) {
+ _thing->signal_change (CHANGE_TYPE_DONE, _property);
+ } else {
+ _thing->signal_change (CHANGE_TYPE_CANCELLED, _property);
+ }
+ }
+
+ void abort ()
+ {
+ _done = false;
+ }
+
+private:
+ T* _thing;
+ int _property;
+ bool _done;
+};
+
+#endif