diff -r cfcbf08528c4 -r 2b40d63a9c3d qtmobility/src/sensors/qsensorbackend.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/qtmobility/src/sensors/qsensorbackend.cpp	Fri Apr 16 15:51:22 2010 +0300
@@ -0,0 +1,220 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Mobility Components.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qsensorbackend.h"
+#include "qsensor_p.h"
+
+QTM_BEGIN_NAMESPACE
+
+/*!
+    \class QSensorBackend
+    \ingroup sensors_backend
+
+    \preliminary
+    \brief The QSensorBackend class is a sensor implementation.
+
+    Sensors on a device will be represented by sub-classes of
+    QSensorBackend.
+*/
+
+/*!
+    \internal
+*/
+QSensorBackend::QSensorBackend(QSensor *sensor)
+    : m_sensor(sensor)
+{
+}
+
+/*!
+    \internal
+*/
+QSensorBackend::~QSensorBackend()
+{
+}
+
+/*!
+    Set the supported \a policies for this sensor.
+    If this isn't called the sensor will not report
+    any supported policies to the user.
+*/
+void QSensorBackend::setSupportedUpdatePolicies(QSensor::UpdatePolicies policies)
+{
+    QSensorPrivate *d = m_sensor->d_func();
+    d->supportedUpdatePolicies = policies;
+}
+
+/*!
+    Notify the QSensor class that a new reading is available.
+*/
+void QSensorBackend::newReadingAvailable()
+{
+    QSensorPrivate *d = m_sensor->d_func();
+
+    // Copy the values from the device reading to the filter reading
+    d->filter_reading->copyValuesFrom(d->device_reading);
+
+    for (QFilterList::const_iterator it = d->filters.constBegin(); it != d->filters.constEnd(); ++it) {
+        QSensorFilter *filter = (*it);
+        if (!filter->filter(d->filter_reading))
+            return;
+    }
+
+    // Copy the values from the filter reading to the cached reading
+    d->cache_reading->copyValuesFrom(d->filter_reading);
+
+    if (d->updatePolicy == QSensor::PolledUpdates)
+        return; // We don't emit the signal if we're polling
+
+    if (d->signalEnabled)
+        Q_EMIT m_sensor->readingChanged();
+}
+
+/*!
+    \fn QSensorBackend::start()
+
+    Start reporting values.
+*/
+
+/*!
+    \fn QSensorBackend::stop()
+
+    Stop reporting values.
+*/
+
+/*!
+    \fn QSensorBackend::poll()
+
+    Poll the sensor for a reading.
+*/
+
+/*!
+    If the backend has lost its reference to the reading
+    it can call this method to get the address.
+
+    Note that you will need to down-cast to the appropriate
+    type.
+
+    \sa setReading()
+*/
+QSensorReading *QSensorBackend::reading() const
+{
+    QSensorPrivate *d = m_sensor->d_func();
+    return d->device_reading;
+}
+
+/*!
+    \fn QSensorBackend::setReading(T *reading)
+
+    This function is called to initialize the \a reading
+    classes used for a sensor.
+
+    If your backend has already allocated a reading you
+    should pass the address of this to the function.
+    Otherwise you should pass 0 and the function will
+    return the address of the reading your backend
+    should use when it wants to notify the sensor API
+    of new readings.
+
+    Note that this is a template function so it should
+    be called with the appropriate type.
+
+    \code
+    class MyBackend : public QSensorBackend
+    {
+        QAccelerometerReading m_reading;
+    public:
+        MyBackend(QSensor *sensor)
+            : QSensorBackend(sensor)
+        {
+            setReading<QAccelerometerReading>(&m_reading);
+        }
+
+        ...
+    \endcode
+
+    Note that this function must be called or you will
+    not be able to send readings to the front end.
+
+    If you do not wish to store the address of the reading
+    you may use the reading() method to get it again later.
+
+    \code
+    class MyBackend : public QSensorBackend
+    {
+    public:
+        MyBackend(QSensor *sensor)
+            : QSensorBackend(sensor)
+        {
+            setReading<QAccelerometerReading>(0);
+        }
+
+        void poll()
+        {
+            qtimestamp timestamp;
+            qreal x, y, z;
+            ...
+            QAccelerometerReading *reading = static_cast<QAccelerometerReading*>(reading());
+            reading->setTimestamp(timestamp);
+            reading->setX(x);
+            reading->setY(y);
+            reading->setZ(z);
+        }
+
+        ...
+    \endcode
+
+    \sa reading()
+*/
+
+/*!
+    \internal
+*/
+void QSensorBackend::setReadings(QSensorReading *device, QSensorReading *filter, QSensorReading *cache)
+{
+    QSensorPrivate *d = m_sensor->d_func();
+    d->device_reading = device;
+    d->filter_reading = filter;
+    d->cache_reading = cache;
+}
+
+#include "moc_qsensorbackend.cpp"
+QTM_END_NAMESPACE
+