2 Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #ifndef DCPOMATIC_SIGNAL_MANAGER_H
21 #define DCPOMATIC_SIGNAL_MANAGER_H
23 #include <boost/asio.hpp>
24 #include <boost/thread.hpp>
28 /** A class to allow signals to be emitted from non-UI threads and handled
31 class SignalManager : public boost::noncopyable
34 /** Create a SignalManager. Must be called from the UI thread */
38 _ui_thread = boost::this_thread::get_id ();
41 virtual ~SignalManager () {}
43 /* Do something next time the UI is idle */
45 void when_idle (T f) {
49 /** Call this in the UI when it is idle */
51 /* This executes one of the functors that has been post()ed to _service */
52 return _service.poll_one ();
55 /** This should wake the UI and make it call ui_idle() */
56 virtual void wake_ui () {
57 /* This is only a sensible implementation when there is no GUI */
62 /** Emit a signal from any thread whose handlers will be called in the UI
63 * thread. Use something like:
65 * ui_signaller->emit (boost::bind (boost::ref (SomeSignal), parameter));
69 if (boost::this_thread::get_id() == _ui_thread) {
70 /* already in the UI thread */
73 /* non-UI thread; post to the service and wake up the UI */
79 friend class Signaller;
81 /** A io_service which is used as the conduit for messages */
82 boost::asio::io_service _service;
83 /** Object required to keep io_service from stopping when it has nothing to do */
84 boost::asio::io_service::work _work;
85 /** The UI thread's ID */
86 boost::thread::id _ui_thread;
89 extern SignalManager* signal_manager;