13
0
livetrax/libs/pbd/timer.cc

162 lines
3.4 KiB
C++

/*
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.
*/
#include "pbd/timer.h"
namespace PBD {
Timer::Timer (unsigned int interval,
const Glib::RefPtr<Glib::MainContext>& main_context)
: m_timeout_source(NULL)
, m_timeout_interval(interval)
, m_main_context(main_context)
, m_suspended(false)
{
}
gboolean
Timer::_timeout_handler (void *data)
{
Timer *const timer = static_cast<Timer*>(data);
return timer->timeout_handler();
}
unsigned int
Timer::get_interval () const
{
return m_timeout_interval;
}
void
Timer::set_interval (unsigned int new_interval)
{
if (new_interval == m_timeout_interval) return;
stop ();
m_timeout_interval = new_interval;
start ();
}
/**
* We don't use Glibmm::TimeoutSource::create() here as contrary
* to the documentation, SignalTimeout::connect and manually
* adding a TimeoutSource to a GMainContext are not equivalent.
*
* SignalTimeout::connect is the equivalent of g_timeout_add in
* terms off callback timing but TimeoutSource tries to adjust
* the timeout based on the time elapsed since the last timeout.
*
* On Windows with a high frequency timeout(40ms) this causes a
* small but noticable increase in CPU Usage.
*/
void
Timer::start()
{
if (m_timeout_source) return;
m_timeout_source = g_timeout_source_new (m_timeout_interval);
#if 0 // support priorites?
if(priority != G_PRIORITY_DEFAULT)
g_source_set_priority(source, priority);
#endif
g_source_set_callback (m_timeout_source, &Timer::_timeout_handler, this, NULL);
g_source_attach (m_timeout_source, m_main_context->gobj());
// GMainContext also holds a reference
}
void
Timer::stop()
{
if (m_timeout_source) {
g_source_destroy (m_timeout_source);
g_source_unref (m_timeout_source);
m_timeout_source = NULL;
}
}
bool
Timer::timeout_handler()
{
return on_elapsed();
}
StandardTimer::StandardTimer(unsigned int interval,
const Glib::RefPtr<Glib::MainContext>& main_context)
: Timer(interval, main_context)
{ }
sigc::connection
StandardTimer::connect(const sigc::slot<void>& slot)
{
if(m_signal.size() == 0) { start(); }
return m_signal.connect(slot);
}
bool
StandardTimer::on_elapsed()
{
if(m_signal.size() == 0)
{
stop();
return false;
}
if (!suspended ()) {
m_signal();
}
return true;
}
BlinkTimer::BlinkTimer(unsigned int interval,
const Glib::RefPtr<Glib::MainContext>& main_context)
: Timer(interval, main_context)
{ }
sigc::connection
BlinkTimer::connect(const sigc::slot<void, bool>& slot)
{
if(m_blink_signal.size() == 0) { start(); }
return m_blink_signal.connect(slot);
}
bool
BlinkTimer::on_elapsed()
{
static bool blink_on = false;
if(m_blink_signal.size() == 0)
{
stop();
return false;
}
if (!suspended ()) {
m_blink_signal(blink_on = !blink_on);
}
return true;
}
} // namespace PBD