src/location/qgeoinfothread_wince.cpp
changeset 0 876b1a06bc25
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/location/qgeoinfothread_wince.cpp	Wed Aug 25 15:49:42 2010 +0300
@@ -0,0 +1,409 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 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 <QMetaType>
+
+#include "qgeoinfothread_wince_p.h"
+
+Q_DECLARE_METATYPE(GPS_POSITION);
+
+QTM_BEGIN_NAMESPACE
+
+// ========== QGeoInfoValidator ==========
+
+QGeoInfoValidator::QGeoInfoValidator() {}
+
+QGeoInfoValidator::~QGeoInfoValidator() {}
+
+// ========== QGeoInfoThreadWinCE ==========
+
+
+// This QGeoInfoThreadWinCE instance takes ownership of the validator, and must delete it before
+// it is destructed.
+QGeoInfoThreadWinCE::QGeoInfoThreadWinCE(QGeoInfoValidator *validator, bool timeoutsForPeriodicUpdates, QObject *parent)
+        : QThread(parent),
+        validator(validator),
+        timeoutsForPeriodicUpdates(timeoutsForPeriodicUpdates),
+        requestScheduled(false),
+        requestInterval(0),
+        updatesScheduled(false),
+        updatesInterval(0),
+        stopping(false),
+        hasLastPosition(false),
+        invalidDataReceived(false),
+        updateTimeoutTriggered(false)
+{
+    qRegisterMetaType<GPS_POSITION>();
+    m_newDataEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
+    m_gpsStateChange = CreateEvent(NULL, FALSE, FALSE, NULL);
+    m_wakeUpEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
+}
+
+QGeoInfoThreadWinCE::~QGeoInfoThreadWinCE()
+{
+    // Let/make the thread finish...
+
+    mutex.lock();
+
+    updatesScheduled = false;
+    requestScheduled = false;
+    stopping = true;
+
+    mutex.unlock();
+
+    wakeUp();
+
+    wait();
+
+    // ...then clean up.
+
+    delete validator;
+
+    CloseHandle(m_newDataEvent);
+    CloseHandle(m_gpsStateChange);
+    CloseHandle(m_wakeUpEvent);
+}
+
+// TODO - just need to add the WinCE line from QTime::currentTime to QDateTime::currentDateTime
+// and we can scrap this method
+QDateTime QGeoInfoThreadWinCE::currentDateTime()
+{
+    QDate d = QDate::currentDate();
+    QTime t = QTime::currentTime();
+
+    // just in case we past midnight in between the last two calls
+    if (d != QDate::currentDate()) {
+        d = QDate::currentDate();
+        t = QTime::currentTime();
+    }
+
+    return QDateTime(d, t);
+}
+
+int QGeoInfoThreadWinCE::msecsTo(QDateTime from, QDateTime to)
+{
+    int MSECS_PER_DAY = 86400000;
+    return (from.date().daysTo(to.date()) * MSECS_PER_DAY) + from.time().msecsTo(to.time());
+}
+
+void QGeoInfoThreadWinCE::requestUpdate(int timeout)
+{
+    QMutexLocker locker(&mutex);
+
+    if (!requestScheduled) {
+        requestScheduled = true;
+
+        if (timeout == 0)
+            timeout = DefaultRequestTimeout;
+
+        requestInterval = timeout;
+        requestNextTime = currentDateTime().addMSecs(requestInterval);
+
+        locker.unlock();
+        wakeUp();
+    }
+}
+
+void QGeoInfoThreadWinCE::startUpdates()
+{
+    QMutexLocker locker(&mutex);
+    if (!updatesScheduled) {
+        updatesScheduled = true;
+        updateTimeoutTriggered = false;
+        hasLastPosition = false;
+
+        if (updatesInterval != 0)
+            updatesNextTime = currentDateTime().addMSecs(updatesInterval);
+
+        locker.unlock();
+        wakeUp();
+    }
+}
+
+void QGeoInfoThreadWinCE::stopUpdates()
+{
+    QMutexLocker locker(&mutex);
+    if (updatesScheduled) {
+        updatesScheduled = false;
+        locker.unlock();
+        wakeUp();
+    }
+}
+
+void QGeoInfoThreadWinCE::setUpdateInterval(int interval)
+{
+    QMutexLocker locker(&mutex);
+
+    if (interval == updatesInterval)
+        return;
+
+    int oldInterval = updatesInterval;
+    updatesInterval = interval;
+
+    if (updatesScheduled) {
+        QDateTime now = currentDateTime();
+
+        // The periodic update interval has been changed and updates are still ocurring.
+
+        if (oldInterval != 0) {
+            if (updatesInterval != 0) {
+                // If we are changing fixed intervals we update the scheduled time for the next
+                // periodic update, making sure that it is scheduled in the future.
+                updatesNextTime = updatesNextTime.addMSecs(updatesInterval - oldInterval);
+                while (msecsTo(now, updatesNextTime) < 0)
+                    updatesNextTime = updatesNextTime.addMSecs(updatesInterval);
+            } else {
+                // If we now want to emit updates as the data arrives we invalidate the scheduled
+                // time for the next update, just to be on the safe side.
+                updatesNextTime = now;
+            }
+        } else {
+            // If we were previously emitting updates as the data arrived we set the scheduled time
+            // for the next periodic update.
+            updatesNextTime = now.addMSecs(updatesInterval);
+        }
+
+        locker.unlock();
+        wakeUp();
+    }
+}
+
+void QGeoInfoThreadWinCE::wakeUp()
+{
+    SetEvent(m_wakeUpEvent);
+    statusUpdated.wakeAll();
+}
+
+// We try to keep the GPS turned off as much as we can to preserve battery life.
+// When run() is called we turn on the GPS device and we leave it on
+// until the request is satisfied or periodic updates are stopped.
+// The methods requestUpdate() and startUpdates() will call start() if required.
+void QGeoInfoThreadWinCE::run()
+{
+    mutex.lock();
+    gpsReachedOnState = false;
+    m_gps = NULL;
+
+    const int handleCount = 3;
+    HANDLE handles[handleCount] = { m_newDataEvent, m_gpsStateChange, m_wakeUpEvent };
+
+    if (updatesScheduled || requestScheduled) {
+        m_gps = GPSOpenDevice(m_newDataEvent, m_gpsStateChange, NULL, 0);
+    }
+
+    while (true) {
+
+        if (stopping)
+            break;
+
+        if (!updatesScheduled && !requestScheduled) {
+            if (m_gps != NULL) {
+                GPSCloseDevice(m_gps);
+                m_gps = NULL;
+            }
+            statusUpdated.wait(&mutex);
+            if (updatesScheduled || requestScheduled) {
+                gpsReachedOnState = false;
+                m_gps = GPSOpenDevice(m_newDataEvent, m_gpsStateChange, NULL, 0);
+            }
+        }
+
+        // If the periodic update is 0 then updates are returned as available.
+        // If this is not the case then the next timeout will be set for whichever of
+        // the request and periodic updates that is due next.
+
+        // We cap the amount of time we spend waiting for updates.
+        DWORD timeout = MaximumMainLoopWaitTime;
+
+        QDateTime now = currentDateTime();
+
+        if (requestScheduled) {
+            if (!updatesScheduled || (updatesInterval == 0)
+                    || (msecsTo(requestNextTime, updatesNextTime) >= 0)) {
+                timeout = msecsTo(now, requestNextTime) + 100;
+            } else {
+                if (updatesInterval != 0)
+                    timeout = msecsTo(now, updatesNextTime) + 100;
+            }
+        } else {
+            // updatesScheduled has to be true or we wouldn't still be in the larger while loop.
+            if (updatesInterval != 0)
+                timeout = msecsTo(now, updatesNextTime) + 100;
+        }
+
+        if (timeout > MaximumMainLoopWaitTime)
+            timeout = MaximumMainLoopWaitTime;
+
+        mutex.unlock();
+        DWORD dwRet = WaitForMultipleObjects(handleCount, handles, FALSE, timeout);
+        mutex.lock();
+
+        // The GPS data has been updated.
+        if (dwRet == WAIT_OBJECT_0) {
+            // The other options are:
+            // dwRet == WAIT_OBJECT_0 + 1
+            //   => The GPS state has been updated.
+            // dwRet == WAIT_OBJECT_0 + 2
+            //   => We called QGeoInfoThreadWinCE::wakeUp().
+            // dwRet == WAIT_TIMEOUT
+            //   => WaitForMultipleObjects() timed out.
+
+            GPS_POSITION posn;
+            posn.dwVersion = GPS_VERSION_1;
+            posn.dwSize = sizeof(posn);
+
+            dwRet = GPSGetPosition(m_gps, &posn, timeout, 0);
+
+            if (dwRet == ERROR_SUCCESS) {
+                if (!validator->valid(posn)) {
+                    invalidDataReceived = true;
+                } else {
+                    m_lastPosition = posn;
+                    hasLastPosition = true;
+                    updateTimeoutTriggered = false;
+
+                    // A request and a periodic update could both be satisfied at once.
+                    // We use this flag to prevent a double update.
+                    bool emitDataUpdated = false;
+
+                    // If a request is in process we emit the dataUpdated signal.
+                    if (requestScheduled) {
+                        emitDataUpdated = true;
+                        requestScheduled = false;
+                    }
+
+                    // If we are updating as data becomes available or if the update period has elapsed
+                    // we emit the dataUpdated signal.
+                    if (updatesScheduled) {
+                        QDateTime now = currentDateTime();
+                        if (updatesInterval == 0) {
+                            emitDataUpdated = true;
+                        } else if (msecsTo(now, updatesNextTime) < 0) {
+                            while (msecsTo(now, updatesNextTime) < 0)
+                                updatesNextTime = updatesNextTime.addMSecs(updatesInterval);
+                            emitDataUpdated = true;
+                        }
+                    }
+
+                    if (emitDataUpdated) {
+                        hasLastPosition = false;
+                        mutex.unlock();
+                        emit dataUpdated(m_lastPosition);
+                        mutex.lock();
+                    }
+                }
+            }
+        }
+        if (dwRet != WAIT_OBJECT_0 || invalidDataReceived) {
+            invalidDataReceived = false;
+
+            // Third party apps may have the ability to turn off the gps hardware independently of
+            // the Microsoft GPS API.
+            // This checks for an unexpected power down and turns the hardware back on.
+
+            // The GPS state has been updated.
+
+            if (dwRet == WAIT_OBJECT_0 + 1) {
+                GPS_DEVICE device;
+                device.dwVersion = GPS_VERSION_1;
+                device.dwSize = sizeof(device);
+
+                dwRet = GPSGetDeviceState(&device);
+
+                if (device.dwDeviceState == SERVICE_STATE_ON) {
+                    gpsReachedOnState = true;
+                } else if ((device.dwDeviceState == SERVICE_STATE_OFF) && gpsReachedOnState) {
+                    // We do not want to mess with devices that are slow starting up, so we only
+                    // turn on devices that have previously reached the "On" state.
+                    gpsReachedOnState = false;
+                    m_gps = GPSOpenDevice(m_newDataEvent, m_gpsStateChange, NULL, 0);
+                }
+            }
+
+            // We reach this point if the gps state has changed, if the wake up event has been
+            // triggered, if we received data we were not interested in from the GPS,
+            // or if a timeout occurred while waiting for gps data.
+            //
+            // In all of these cases we should check for request and periodic update timeouts.
+
+            QDateTime now = currentDateTime();
+
+            bool emitUpdateTimeout = false;
+
+            // Check for request timeouts.
+            if (requestScheduled && msecsTo(now, requestNextTime) < 0) {
+                requestScheduled = false;
+                emitUpdateTimeout = true;
+            }
+
+            // Check to see if a periodic update is due.
+            if (updatesScheduled && updatesInterval != 0 && (msecsTo(now, updatesNextTime) < 0)) {
+                while (msecsTo(now, updatesNextTime) < 0)
+                    updatesNextTime = updatesNextTime.addMSecs(updatesInterval);
+                if (hasLastPosition) {
+                    hasLastPosition = false;
+                    mutex.unlock();
+                    emit dataUpdated(m_lastPosition);
+                    mutex.lock();
+                } else {
+                    if (timeoutsForPeriodicUpdates && !updateTimeoutTriggered) {
+                        updateTimeoutTriggered = true;
+                        emitUpdateTimeout = true;
+                    }
+                }
+            }
+
+            if (emitUpdateTimeout) {
+                mutex.unlock();
+                emit updateTimeout();
+                mutex.lock();
+            }
+        }
+    }
+
+    if (m_gps != NULL)
+        GPSCloseDevice(m_gps);
+
+    mutex.unlock();
+}
+
+#include "moc_qgeoinfothread_wince_p.cpp"
+QTM_END_NAMESPACE