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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <qabstracteventdispatcher.h>
#include <qevent.h>
#include <QCoreApplication>
#include <QThread>
#include <qtimer.h>
#include "base/message_pump_qt.h"
#include <fcntl.h>
#include <limits>
#include <math.h>
#include "base/eintr_wrapper.h"
#include "base/logging.h"
#include "base/platform_thread.h"
namespace {
// Cached QEvent user type, registered for our event system
static int sPokeEvent;
} // namespace
namespace base {
MessagePumpForUI::MessagePumpForUI()
: state_(NULL),
qt_pump(*this)
{
}
MessagePumpForUI::~MessagePumpForUI() {
}
MessagePumpQt::MessagePumpQt(MessagePumpForUI &aPump)
: pump(aPump), mTimer(new QTimer(this))
{
// Register our custom event type, to use in qApp event loop
sPokeEvent = QEvent::registerEventType();
connect(mTimer, SIGNAL(timeout()), this, SLOT(dispatchDelayed()));
mTimer->setSingleShot(true);
}
MessagePumpQt::~MessagePumpQt()
{
mTimer->stop();
delete mTimer;
}
bool
MessagePumpQt::event(QEvent *e)
{
if (e->type() == sPokeEvent) {
pump.HandleDispatch();
return true;
}
return false;
}
void
MessagePumpQt::scheduleDelayedIfNeeded(const TimeTicks& delayed_work_time)
{
if (delayed_work_time.is_null()) {
return;
}
if (mTimer->isActive()) {
mTimer->stop();
}
TimeDelta later = delayed_work_time - TimeTicks::Now();
// later.InMilliseconds() returns an int64_t, QTimer only accepts int's for start(),
// std::min only works on exact same types.
int laterMsecs = later.InMilliseconds() > std::numeric_limits<int>::max() ?
std::numeric_limits<int>::max() : later.InMilliseconds();
mTimer->start(laterMsecs > 0 ? laterMsecs : 0);
}
void
MessagePumpQt::dispatchDelayed()
{
pump.HandleDispatch();
}
void MessagePumpForUI::Run(Delegate* delegate) {
RunState state;
state.delegate = delegate;
state.should_quit = false;
state.run_depth = state_ ? state_->run_depth + 1 : 1;
// We really only do a single task for each iteration of the loop. If we
// have done something, assume there is likely something more to do. This
// will mean that we don't block on the message pump until there was nothing
// more to do. We also set this to true to make sure not to block on the
// first iteration of the loop, so RunAllPending() works correctly.
bool more_work_is_plausible = true;
RunState* previous_state = state_;
state_ = &state;
for(;;) {
QEventLoop::ProcessEventsFlags block = QEventLoop::AllEvents;
if (!more_work_is_plausible) {
block |= QEventLoop::WaitForMoreEvents;
}
QAbstractEventDispatcher* dispatcher =
QAbstractEventDispatcher::instance(QThread::currentThread());
// An assertion seems too much here, as during startup,
// the dispatcher might not be ready yet.
if (!dispatcher) {
return;
}
// processEvent's returns true if an event has been processed.
more_work_is_plausible = dispatcher->processEvents(block);
if (state_->should_quit) {
break;
}
more_work_is_plausible |= state_->delegate->DoWork();
if (state_->should_quit) {
break;
}
more_work_is_plausible |=
state_->delegate->DoDelayedWork(&delayed_work_time_);
if (state_->should_quit) {
break;
}
qt_pump.scheduleDelayedIfNeeded(delayed_work_time_);
if (more_work_is_plausible) {
continue;
}
more_work_is_plausible = state_->delegate->DoIdleWork();
if (state_->should_quit) {
break;
}
}
state_ = previous_state;
}
void MessagePumpForUI::HandleDispatch() {
if (state_->should_quit) {
return;
}
if (state_->delegate->DoWork()) {
// there might be more, see more_work_is_plausible
// variable above, that's why we ScheduleWork() to keep going.
ScheduleWork();
}
if (state_->should_quit) {
return;
}
state_->delegate->DoDelayedWork(&delayed_work_time_);
qt_pump.scheduleDelayedIfNeeded(delayed_work_time_);
}
void MessagePumpForUI::Quit() {
if (state_) {
state_->should_quit = true;
} else {
NOTREACHED() << "Quit called outside Run!";
}
}
void MessagePumpForUI::ScheduleWork() {
QCoreApplication::postEvent(&qt_pump,
new QEvent((QEvent::Type) sPokeEvent));
}
void MessagePumpForUI::ScheduleDelayedWork(const TimeTicks& delayed_work_time) {
// On GLib implementation, a work source is defined which explicitly checks the
// time that has passed. Here, on Qt we can use a QTimer that enqueues our
// event signal in an event queue.
delayed_work_time_ = delayed_work_time;
qt_pump.scheduleDelayedIfNeeded(delayed_work_time_);
}
} // namespace base
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