1 files changed, 70 insertions, 0 deletions
diff --git a/src/lib/signal.h b/src/lib/signal.h
new file mode 100644
index 000000000..03b440e79
--- /dev/null
+++ b/src/lib/signal.h
@@ -0,0 +1,70 @@
+/*
+    Copyright (C) 2013-2021 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_SIGNAL_H
+#define DCPOMATIC_SIGNAL_H
+
+
+#include "signaller.h"
+#include "util.h"
+#include <boost/signals2.hpp>
+#include <utility>
+
+
+/** Wrapper for a boost::signals2::signal that asserts that emissions are made from the
+ *  UI thead, so anything connected to it will be guaranteed to be called from there.
+ */
+template <typename T>
+class UISignal
+{
+public:
+	template <typename... Args>
+	void emit_ui(Signaller* signaller, Args&&... args) const
+	{
+		signaller->emit(boost::bind(boost::ref(_wrapped), std::forward<Args>(args)...));
+	}
+
+	template <typename... Args>
+	void emit(Args&&... args) const
+	{
+		ensure_ui_thread();
+		_wrapped(std::forward<Args>(args)...);
+	}
+
+	template <typename... Args>
+	boost::signals2::connection connect(Args&&... args)
+	{
+		return _wrapped.connect(std::forward<Args>(args)...);
+	}
+
+	template <typename... Args>
+	void operator()(Args&&... args) const
+	{
+		emit(std::forward<Args>(args)...);
+	}
+
+private:
+	boost::signals2::signal<T> _wrapped;
+};
+
+
+#endif
+