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GPS and Web Service using C++ ATL/WTL (Windows Mobile 6, Standard)

, 18 Jan 2008 CPOL
This article explains how to use the GPS API and Web Service on a SmartPhone to show demographics information for the current location.
gpsdemographics.zip
GPSDemographicsSetup
GPSDemographicsSetup.vddproj
GPSDemographics
com_cdynews
DemographixQuery.disco
DemographixQuery.wsdl
results.discomap
res
background.bmp
Demographics.ico
gpsdemographicssetupcab.zip
GPSDemographicsSetup.CAB
#include "StdAfx.h"
#include "GPSDevice.h"

CGPSDevice * CGPSDevice::s_pInstance = NULL;

#define MAX_WAIT    5000
#define MAX_AGE     3000
#define GPS_CONTROLLER_EVENT_COUNT 3

CGPSDevice::CGPSDevice(void)
{
	m_pSink = NULL;
	m_hGPS_Device = NULL;
	m_hNewLocationData = NULL;
	m_hDeviceStateChange = NULL;
	m_hExitThread = NULL;
}

CGPSDevice::~CGPSDevice(void)
{
}

CGPSDevice * CGPSDevice::Instance()
{
	if( CGPSDevice::s_pInstance == NULL )
	{
		s_pInstance = new CGPSDevice();
	}

	return CGPSDevice::s_pInstance;
}

DWORD WINAPI CGPSDevice::GPSThreadProc(__opt LPVOID lpParameter)
{
    DWORD dwRet = 0;
    GPS_POSITION gps_Position = {0};
    GPS_DEVICE gps_Device = {0};
    

	CGPSDevice * pDevice = (CGPSDevice*) lpParameter;

	HANDLE gpsHandles[GPS_CONTROLLER_EVENT_COUNT] = 
	{	pDevice->m_hNewLocationData, 
        pDevice->m_hDeviceStateChange,
        pDevice->m_hExitThread
    };

    gps_Position.dwSize = sizeof(gps_Position);
    gps_Position.dwVersion = GPS_VERSION_1;

    gps_Device.dwVersion = GPS_VERSION_1;
    gps_Device.dwSize = sizeof(gps_Device);

    do
    {
        dwRet = WaitForMultipleObjects(
			GPS_CONTROLLER_EVENT_COUNT, 
			gpsHandles, FALSE, INFINITE);

        if (dwRet == WAIT_OBJECT_0)
        {
            dwRet = GPSGetPosition(
				pDevice->m_hGPS_Device, 
				&gps_Position, MAX_AGE, 0);

            if (ERROR_SUCCESS != dwRet)
                continue;
            else
				pDevice->m_pSink->SetGPSPosition(gps_Position);
        }
        else if (dwRet == WAIT_OBJECT_0 + 1)
        {
            dwRet = GPSGetDeviceState(&gps_Device);	

            if (ERROR_SUCCESS != dwRet)
                continue;
            else
                pDevice->m_pSink->SetGPSDeviceInfo(gps_Device);
        }
        else if (dwRet == WAIT_OBJECT_0 + 2)
            break;
        else
            ASSERT(0);
    
	} while( TRUE );

	return 0;
}

HRESULT CGPSDevice::StartThread()
{
	HRESULT hr = E_FAIL;
	DWORD dwRet = 0;

	m_hNewLocationData = CreateEvent(NULL, FALSE, FALSE, NULL);

	if ( m_hNewLocationData )
	{
		m_hDeviceStateChange = CreateEvent(NULL, FALSE, FALSE, NULL);
		
		if (m_hDeviceStateChange)
		{

			m_hExitThread = CreateEvent(NULL, FALSE, FALSE, NULL);
			if (m_hExitThread)
			{
				
				m_hThread = ::CreateThread(NULL, NULL, 
					GPSThreadProc, this, NULL, &m_dwThreadID);
				
				if ( m_hThread )
					hr = S_OK;
			}
		}
	}

	if( FAILED(hr) )
	{
		dwRet = GetLastError();
		hr = HRESULT_FROM_WIN32(dwRet);
	}

	if (FAILED(hr))
	{
		if (m_hNewLocationData)
		{
			CloseHandle(m_hNewLocationData);
			m_hNewLocationData = NULL;
		}

		if (m_hDeviceStateChange)
		{
			CloseHandle(m_hDeviceStateChange);
			m_hDeviceStateChange = NULL;
		}

		if (m_hExitThread)
		{
			CloseHandle(m_hExitThread);
			m_hExitThread = NULL;
		}
	}
	return hr;	
}

HRESULT CGPSDevice::StopThread()
{
    HRESULT hr = E_FAIL;
    DWORD dwRet = 0;

    if( SetEvent(m_hExitThread) )
    {
		dwRet = WaitForSingleObject(m_hThread, MAX_WAIT);
		if(WAIT_OBJECT_0 == dwRet)
			hr = S_OK;
	}

	if( FAILED(hr) )
	{
        dwRet = GetLastError();
        hr = HRESULT_FROM_WIN32(dwRet);
	}

	if (m_hNewLocationData)
    {
        CloseHandle(m_hNewLocationData);
        m_hNewLocationData = NULL;
    }

    if (m_hDeviceStateChange)
    {
        CloseHandle(m_hDeviceStateChange);
        m_hDeviceStateChange = NULL;
    }

    if (m_hExitThread)
    {
        CloseHandle(m_hExitThread);
        m_hExitThread = NULL;
    }

    if (m_hThread)
    {
        CloseHandle(m_hThread);
        m_hThread = NULL;
		m_dwThreadID = 0;
    }

    return hr;
}

HRESULT CGPSDevice::TurnOn(IGPSSink * pSink)
{
	if( !pSink )
		return E_INVALIDARG;

	CGPSDevice * pDevice = Instance();

	//We already have a device opened
	if( pDevice->m_hGPS_Device )
		return E_UNEXPECTED;

	if( pDevice->m_pSink != NULL )
		return E_UNEXPECTED;

	pDevice->m_pSink = pSink;

	HRESULT hr = pDevice->StartThread();

	if( SUCCEEDED(hr) )
	{
		pDevice->m_hGPS_Device = GPSOpenDevice( 
			pDevice->m_hNewLocationData, 
			pDevice->m_hDeviceStateChange, 
			NULL, NULL);

		if( pDevice->m_hGPS_Device )
			hr = S_OK;
		else
			hr = HRESULT_FROM_WIN32(GetLastError());
	}

	if( FAILED(hr) )
		TurnOff();

	return hr;
}

HRESULT CGPSDevice::TurnOff()
{
	CGPSDevice * pDevice = Instance();

	if( !pDevice->m_hGPS_Device )
		return E_UNEXPECTED;	

	HRESULT hr = pDevice->StopThread();


	pDevice->m_pSink = NULL;

	DWORD dwRet = GPSCloseDevice(pDevice->m_hGPS_Device);
    pDevice->m_hGPS_Device = NULL;

	if( SUCCEEDED(hr) )
	{
		if( ERROR_SUCCESS != dwRet )
	        hr = HRESULT_FROM_WIN32(GetLastError());
	}

	return hr;
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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About the Author

Valentin Ivanov
Chief Technology Officer CDYNE Corporation
United States United States
Developer, Maker and Tinkerer

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