/*
* Copyright (C) 2013 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "core/frame/DeviceSensorEventDispatcher.h"
namespace WebCore {
DeviceSensorEventDispatcher::DeviceSensorEventDispatcher()
: m_needsPurge(false)
, m_isDispatching(false)
{
}
DeviceSensorEventDispatcher::~DeviceSensorEventDispatcher()
{
}
void DeviceSensorEventDispatcher::addController(DeviceSensorEventController* controller)
{
bool wasEmpty = m_controllers.isEmpty();
if (!m_controllers.contains(controller))
m_controllers.append(controller);
if (wasEmpty)
startListening();
}
void DeviceSensorEventDispatcher::removeController(DeviceSensorEventController* controller)
{
// Do not actually remove the controller from the vector, instead zero them out.
// The zeros are removed in these two cases:
// 1. either immediately if we are not dispatching any events,
// 2. or after events to all controllers have dispatched
// (see e.g. DeviceOrientationDispatcher::didChangeDeviceOrientation).
// This is to correctly handle the re-entrancy case when a controller is destroyed
// while the events are still being dispatched.
size_t index = m_controllers.find(controller);
if (index == kNotFound)
return;
m_controllers[index] = 0;
m_needsPurge = true;
if (!m_isDispatching)
purgeControllers();
}
void DeviceSensorEventDispatcher::purgeControllers()
{
ASSERT(m_needsPurge);
size_t i = 0;
while (i < m_controllers.size()) {
if (!m_controllers[i]) {
m_controllers[i] = m_controllers.last();
m_controllers.removeLast();
} else {
++i;
}
}
m_needsPurge = false;
if (m_controllers.isEmpty())
stopListening();
}
} // namespace WebCore