Add PBD::Timer/StandardTimer/BlinkTimer classes for convenient timeouts

libs/pbd/pbd/timer.h

@@ -0,0 +1,121 @@
+/*
+    Copyright (C) 2014 Tim Mayberry
+
+    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) any later version.
+
+    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, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __libpbd_timer_h__
+#define __libpbd_timer_h__
+
+#include <sigc++/signal.h>
+
+#include <glibmm/main.h>
+
+#include "pbd/libpbd_visibility.h"
+
+namespace PBD {
+
+/**
+ * The Timer class is a wrapper around Glib TimeoutSources
+ * The Timer will start automatically when the first connection
+ * is made and stop when the last callback is disconnected.
+ */
+class LIBPBD_API Timer
+{
+public:
+
+	Timer (unsigned int interval,
+	       const Glib::RefPtr<Glib::MainContext>& main_context);
+
+	unsigned int get_interval () const;
+
+	void set_interval (unsigned int new_interval);
+
+	virtual unsigned int connection_count () const = 0;
+
+protected:
+
+	virtual ~Timer() { }
+
+	void start ();
+
+	void stop ();
+
+	virtual bool on_elapsed () = 0;
+
+private:
+
+	Timer(const Timer&);
+	Timer& operator= (const Timer&);
+
+private:
+
+	static gboolean _timeout_handler (void *data);
+
+	bool timeout_handler ();
+
+	GSource*                               m_timeout_source;
+
+	unsigned int                           m_timeout_interval;
+
+	const Glib::RefPtr<Glib::MainContext>  m_main_context;
+
+};
+
+class LIBPBD_API StandardTimer : public Timer
+{
+public:
+
+	StandardTimer (unsigned int interval,
+	               const Glib::RefPtr<Glib::MainContext>& main_context = Glib::MainContext::get_default());
+
+	sigc::connection connect (const sigc::slot<void>& slot);
+
+	virtual unsigned int connection_count () const
+	{ return m_signal.size (); }
+
+protected:
+
+	virtual bool on_elapsed ();
+
+	sigc::signal<void>                  m_signal;
+
+};
+
+class LIBPBD_API BlinkTimer : public Timer
+{
+public:
+
+	BlinkTimer (unsigned int interval,
+	            const Glib::RefPtr<Glib::MainContext>& main_context = Glib::MainContext::get_default());
+
+
+	sigc::connection connect (const sigc::slot<void, bool>& slot);
+
+	virtual unsigned int connection_count () const
+	{ return m_blink_signal.size (); }
+
+protected:
+
+	virtual bool on_elapsed ();
+
+	sigc::signal<void, bool> m_blink_signal;
+
+};
+
+} // namespace PBD
+
+#endif // __libpbd_timer_h__