beeper.cpp

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/*
 * BEEPER.CPP
 * Beeper Automation Object #3 Chapter 14
 *
 * Implementation of the CBeeper class demonstrating the use of
 * standard error handling that ties in with ITypeInfo::Invoke
 * (as well as DispInvoke).  This includes an implementation of
 * ISupportErrorInfo.
 *
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved
 *
 * Kraig Brockschmidt, Microsoft
 * Internet  :  [e-mail]
 * Compuserve:  >INTERNET:[e-mail]
 */


#include "beeper.h"

extern HINSTANCE g_hInst;

#ifdef WIN32
extern DWORD     g_dwTLS;
#else
LANGID           g_langID;
#endif


/*
 * CBeeper::CBeeper
 * CBeeper::~CBeeper
 *
 * Parameters (Constructor):
 *  pUnkOuter       LPUNKNOWN of a controlling unknown.
 *  pfnDestroy      PFNDESTROYED to call when an object
 *                  is destroyed.
 */

CBeeper::CBeeper(LPUNKNOWN pUnkOuter, PFNDESTROYED pfnDestroy)
    {
    m_cRef=0;
    m_pUnkOuter=pUnkOuter;
    m_pfnDestroy=pfnDestroy;

    m_lSound=0;
    m_pImpIDispatch=NULL;
    return;
    }


CBeeper::~CBeeper(void)
    {
    DeleteInterfaceImp(m_pImpIDispatch);
    return;
    }



/*
 * CBeeper::Init
 *
 * Purpose:
 *  Performs any intiailization of a CBeeper that's prone to failure
 *  that we also use internally before exposing the object outside.
 *
 * Parameters:
 *  None
 *
 * Return Value:
 *  BOOL            TRUE if the function is successful,
 *                  FALSE otherwise.
 */

BOOL CBeeper::Init(void)
    {
    LPUNKNOWN       pIUnknown=this;

    if (NULL!=m_pUnkOuter)
        pIUnknown=m_pUnkOuter;

    m_pImpIDispatch=new CImpIDispatch(this, pIUnknown);

    if (NULL==m_pImpIDispatch)
        return FALSE;

    return TRUE;
    }




/*
 * CBeeper::QueryInterface
 * CBeeper::AddRef
 * CBeeper::Release
 */

STDMETHODIMP CBeeper::QueryInterface(REFIID riid, PPVOID ppv)
    {
    *ppv=NULL;

    /*
     * The only calls for IUnknown are either in a nonaggregated
     * case or when created in an aggregation, so in either case
     * always return our IUnknown for IID_IUnknown.
     *
     * Note that IBeeper is implemented on CBeeper, and we must
     * also expose that custom interface through QueryInterface.
     */
    if (IID_IUnknown==riid || IID_IBeeper==riid)
        *ppv=this;

    /*
     * QueryInterface must respond not only to IID_IDispatch for
     * the primary automation interface, but also to the IID of the
     * dispinterface itself, which in our case is DIID_DIBeeper.
     */
    if (IID_IDispatch==riid || DIID_DIBeeper==riid)
        *ppv=m_pImpIDispatch;

    //Indicate that we support error information
    if (IID_ISupportErrorInfo==riid)
        *ppv=m_pImpISuppErr;

    //AddRef any interface we'll return.
    if (NULL!=*ppv)
        {
        ((LPUNKNOWN)*ppv)->AddRef();
        return NOERROR;
        }

    return ResultFromScode(E_NOINTERFACE);
    }


STDMETHODIMP_(ULONG) CBeeper::AddRef(void)
    {
    return ++m_cRef;
    }


STDMETHODIMP_(ULONG) CBeeper::Release(void)
    {
    if (0L!=--m_cRef)
        return m_cRef;

    if (NULL!=m_pfnDestroy)
        (*m_pfnDestroy)();

    delete this;
    return 0L;
    }




//IBeeper interface functions

/*
 * CBeeper::get_Sound
 * CBeeper::put_Sound
 *
 * Purpose:
 *  Functions called from DispInvoke to handle the Sound property.
 *
 * Parameters (Set only):
 *  lSound          long, new sound to save after validation
 *
 * Return Value: (Get only):
 *  long            Current sound.
 */

STDMETHODIMP_(long) CBeeper::get_Sound(void)
    {
    return m_lSound;
    }


STDMETHODIMP_(void) CBeeper::put_Sound(long lSound)
    {
    if (MB_OK!=lSound && MB_ICONEXCLAMATION!=lSound
        && MB_ICONQUESTION!=lSound && MB_ICONHAND!=lSound
        && MB_ICONASTERISK!=lSound)
        {
        /*
         * Since we cannot return a value to ITypeInfo::Invoke to
         * indicate an exception condition, we'll use
         * m_pImpIDispatch->Exception to raise them.  This
         * Exception function now uses the error info mechanism
         * to raise exceptions rather than relying on our own
         * single-threaded model as used in Beeper #2.
         */
        m_pImpIDispatch->Exception(EXCEPTION_INVALIDSOUND);
        return;
        }

    m_lSound=lSound;
    return;
    }


/*
 * CBeeper::Beep
 *
 * Purpose:
 *  Function called from DispInvoke to invoke the Beep method.
 *
 * Return Value:
 *  long           The sound played.
 */

STDMETHODIMP_(long) CBeeper::Beep(void)
    {
    MessageBeep((UINT)m_lSound);
    return m_lSound;
    }





//IDispatch interface implementation

/*
 * CImpIDispatch::CImpIDispatch
 * CImpIDispatch::~CImpIDispatch
 *
 * Parameters (Constructor):
 *  pObj            PCBeeper of the object we're in.
 *  pUnkOuter       LPUNKNOWN to which we delegate.
 */

CImpIDispatch::CImpIDispatch(PCBeeper pObj, LPUNKNOWN pUnkOuter)
    {
    m_cRef=0;
    m_pObj=pObj;
    m_pUnkOuter=pUnkOuter;

    //These are created as needed in GetTypeInfo
    m_pITINeutral=NULL;
    m_pITIGerman=NULL;
    return;
    }

CImpIDispatch::~CImpIDispatch(void)
    {
    ReleaseInterface(m_pITIGerman);
    ReleaseInterface(m_pITINeutral);
    return;
    }



/*
 * CImpIDispatch::QueryInterface
 * CImpIDispatch::AddRef
 * CImpIDispatch::Release
 *
 * Purpose:
 *  IUnknown members for CImpIDispatch object.
 */

STDMETHODIMP CImpIDispatch::QueryInterface(REFIID riid, PPVOID ppv)
    {
    return m_pUnkOuter->QueryInterface(riid, ppv);
    }


STDMETHODIMP_(ULONG) CImpIDispatch::AddRef(void)
    {
    ++m_cRef;
    return m_pUnkOuter->AddRef();
    }

STDMETHODIMP_(ULONG) CImpIDispatch::Release(void)
    {
    --m_cRef;
    return m_pUnkOuter->Release();
    }



/*
 * CImpIDispatch::GetTypeInfoCount
 *
 * Purpose:
 *  Returns the number of type information (ITypeInfo) interfaces
 *  that the object provides (0 or 1).
 *
 * Parameters:
 *  pctInfo         UINT * to the location to receive
 *                  the count of interfaces.
 *
 * Return Value:
 *  HRESULT         NOERROR or a general error code.
 */

STDMETHODIMP CImpIDispatch::GetTypeInfoCount(UINT *pctInfo)
    {
    //We implement GetTypeInfo so return 1
    *pctInfo=1;
    return NOERROR;
    }




/*
 * CImpIDispatch::GetTypeInfo
 *
 * Purpose:
 *  Retrieves type information for the automation interface.  This
 *  is used anywhere that the right ITypeInfo interface is needed
 *  for whatever LCID is applicable.  Specifically, this is used
 *  from within GetIDsOfNames and Invoke.
 *
 * Parameters:
 *  itInfo          UINT reserved.  Must be zero.
 *  lcid            LCID providing the locale for the type
 *                  information.  If the object does not support
 *                  localization, this is ignored.
 *  ppITypeInfo     ITypeInfo ** in which to store the ITypeInfo
 *                  interface for the object.
 *
 * Return Value:
 *  HRESULT         NOERROR or a general error code.
 */

STDMETHODIMP CImpIDispatch::GetTypeInfo(UINT itInfo, LCID lcid
    , ITypeInfo **ppITypeInfo)
    {
    HRESULT     hr;
    ITypeLib   *pITypeLib;
    ITypeInfo **ppITI=NULL;

    if (0!=itInfo)
        return ResultFromScode(TYPE_E_ELEMENTNOTFOUND);

    if (NULL==ppITypeInfo)
        return ResultFromScode(E_POINTER);

    *ppITypeInfo=NULL;

    /*
     * Since we returned one from GetTypeInfoCount, this function
     * can be called for a specific locale.  We support English,
     * German, and neutral (defaults to English) locales.  Anything
     * else is an error.
     *
     * After this switch statement, ppITI will either be NULL or
     * a valid pointer in it after.  If NULL, we know we need to
     * load type information, retrieve the ITypeInfo we want, and
     * then store it in *ppITI.
     */
    switch (PRIMARYLANGID(lcid))
        {
        case LANG_NEUTRAL:
        case LANG_ENGLISH:
            ppITI=&m_pITINeutral;
            break;

        case LANG_GERMAN:
            ppITI=&m_pITIGerman;
            break;

        default:
            return ResultFromScode(DISP_E_UNKNOWNLCID);
        }

    //Load a type lib if we don't have the information already.
    if (NULL==*ppITI)
        {
        /*
         * The type libraries are registered under 0 (neutral),
         * 7 (German), and 9 (English) with no specific sub-
         * language, which would make them 407 or 409 and such.
         * If you are sensitive to sub-languages, then use the
         * full LCID instead of just the LANGID as done here.
         */
        hr=LoadRegTypeLib(LIBID_BeeperTypeLibrary, 1, 0
            , PRIMARYLANGID(lcid), &pITypeLib);

        /*
         * If LoadRegTypeLib fails, try loading directly with
         * LoadTypeLib, which will register the library for us.
         * Note that there's no default case here because the
         * prior switch will have filtered lcid already.