ISO C++禁止声明 ..没有类型

我正在使用C++为maemo制作Qt移动应用程序。

我有我的类声明，但出现此错误：

ISO C++ forbids declaration of 'QGeoPositionInfoSource' with no type

我的代码如下：

电话助手.h

#ifndef PHONEHELPER_H
#define PHONEHELPER_H
#include <QObject>
#include <QGeoPositionInfoSource>

class PhoneHelper : public QObject
{
    Q_OBJECT
public:
    explicit PhoneHelper(QObject *parent = 0);
    void GetGPSData(const char * callbackSlot);
private:
    /*
     * The error occures here on the line below */
    QGeoPositionInfoSource *gpsSource;         // PROBLEM HERE
private slots:
    void positionUpdated(const QGeoPositionInfo &info);
};
#endif // PHONEHELPER_H

电话助手.cpp

#include "phonehelper.h"
PhoneHelper::PhoneHelper(QObject *parent) :
    QObject(parent)
{
}
PhoneHelper::GetGPSData(const char *callbackSlot)
{
    gpsSource = QGeoPositionInfoSource::createDefaultSource(this);
             if (gpsSource) {
                 connect(source, SIGNAL(positionUpdated(QGeoPositionInfo)),
                         this, SLOT(positionUpdated(QGeoPositionInfo)));
                 connect(source, SIGNAL(positionUpdated(QGeoPositionInfo)),
                         this, SLOT(callbackSlot(QGeoPositionInfo)));
                 gpsSource->startUpdates();
             }
}
PhoneHelper::positionUpdated(const QGeoPositionInfo &info)
{
        gpsSource->stopUpdates();
        delete gpsSource;
}

Project.pro

DEPLOYMENTFOLDERS = # file1 dir1
symbian:TARGET.UID3 = 0xE0EEBE99

symbian:TARGET.CAPABILITY += NetworkServices
# MOBILITY variable.
CONFIG += mobility
MOBILITY += location
SOURCES += main.cpp mainwindow.cpp 
    phonehelper.cpp
HEADERS += mainwindow.h 
    phonehelper.h
FORMS += mainwindow.ui

include(deployment.pri)
qtcAddDeployment()

上述错误是什么意思？