IADVSINK.CPP

/* 
 * IADVSINK.CPP 
 * Data Object User Chapter 10 
 * 
 * Implementation of an object with IAdviseSink. 
 * 
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved 
 * 
 * Kraig Brockschmidt, Microsoft 
 * Internet  :  kraigb@microsoft.com 
 * Compuserve:  >INTERNET:kraigb@microsoft.com 
 */ 
 
 
#include "datauser.h" 
 
 
/* 
 * CAdviseSink::CAdviseSink 
 * CAdviseSink::~CAdviseSink 
 * 
 * Parameters (Constructor): 
 *  pApp            PAPP to the application 
 * 
 */ 
 
CAdviseSink::CAdviseSink(PAPP pApp) 
    { 
    m_cRef=0; 
    m_pApp=pApp; 
    return; 
    } 
 
CAdviseSink::~CAdviseSink(void) 
    { 
    return; 
    } 
 
 
 
 
/* 
 * CAdviseSink::QueryInterface 
 * CAdviseSink::AddRef 
 * CAdviseSink::Release 
 * 
 * Purpose: 
 *  IUnknown members for CAdviseSink object. 
 */ 
 
STDMETHODIMP CAdviseSink::QueryInterface(REFIID riid, PPVOID ppv) 
    { 
    *ppv=NULL; 
 
    if (IID_IUnknown==riid || IID_IAdviseSink==riid) 
        *ppv=this; 
 
    if (NULL!=*ppv) 
        { 
        ((LPUNKNOWN)*ppv)->AddRef(); 
        return NOERROR; 
        } 
 
    return ResultFromScode(E_NOINTERFACE); 
    } 
 
 
STDMETHODIMP_(ULONG) CAdviseSink::AddRef(void) 
    { 
    return ++m_cRef; 
    } 
 
 
STDMETHODIMP_(ULONG) CAdviseSink::Release(void) 
    { 
    if (0!=--m_cRef) 
        return m_cRef; 
 
    delete this; 
    return 0; 
    } 
 
 
 
 
/* 
 * CAdviseSink::OnDataChange 
 * 
 * Purpose: 
 *  Notifes the advise sink that data changed in a data object. 
 *  On this message you may request a new data rendering and update 
 *  your displays as necessary.  Any data sent to this function is 
 *  owned by the caller, not by this advise sink. 
 * 
 *  All Advise Sink methods are asynchronous and therefore we 
 *  should attempt no synchronous calls from within them to an EXE 
 *  object.  If we do, we'll get RPC_E_CALLREJECTED as shown below. 
 * 
 * Parameters: 
 *  pFEIn           LPFORMATETC describing format that changed 
 *  pSTM            LPSTGMEDIUM providing the medium in which the 
 *                  data is provided. 
 * 
 * Return Value: 
 *  None 
 */ 
 
 
STDMETHODIMP_(void) CAdviseSink::OnDataChange(LPFORMATETC pFE 
    , LPSTGMEDIUM pSTM) 
    { 
    BOOL        fUsable=TRUE; 
    UINT        cf; 
    STGMEDIUM   stm; 
 
    /* 
     * We first check that the changed data is, in fact, a format 
     * we're interested in, either CF_TEXT, CF_BITMAP, or 
     * CF_METAFILEPICT, then only in the aspects we want.  We check 
     * if pSTM->tymed is TYMED_NULL or something else.  If NULL, we 
     * just exit so the data object can time ADVF_NODATA trans- 
     * actions.  Otherwise we verify that the data is useful and 
     * repaint. If there is data in pSTM we are responsible for it. 
     */ 
 
    //Ignore the m_fGetData flag for EXE objects (we can't GetData) 
    if (!m_pApp->m_fGetData && !m_pApp->m_fEXE) 
        return; 
 
    //See if we're interested in the format and aspect that changed 
    cf=pFE->cfFormat; 
 
    if ((CF_TEXT!=cf && CF_BITMAP!=cf && CF_METAFILEPICT!=cf) 
        || !(DVASPECT_CONTENT & pFE->dwAspect)) 
        return; 
 
    //Check the medium if we got data 
    switch (cf) 
        { 
        case CF_TEXT: 
            fUsable=(BOOL)(TYMED_HGLOBAL & pFE->tymed); 
            break; 
 
        case CF_BITMAP: 
            fUsable=(BOOL)(TYMED_GDI & pFE->tymed); 
            break; 
 
        case CF_METAFILEPICT: 
            fUsable=(BOOL)(TYMED_MFPICT & pFE->tymed); 
            break; 
 
        default: 
            break; 
        } 
 
    if (!fUsable) 
        return; 
 
    if (NULL==m_pApp->m_pIDataObject) 
        return; 
 
    /* 
     * When dealing with EXE objects, invalidate ourselves 
     * after setting TYMED_NULL in our STGMEDIUM that causes 
     * CAppVars::Paint to request new data.  We cannot call 
     * GetData in here because this is an async call when we're 
     * dealing with an EXE. 
     */ 
    if (m_pApp->m_fEXE) 
        { 
        ReleaseStgMedium(&(m_pApp->m_stm)); 
        m_pApp->m_cf=cf; 
        m_pApp->m_stm.tymed=TYMED_NULL; 
 
        InvalidateRect(m_pApp->m_hWnd, NULL, TRUE); 
        return; 
        } 
 
    if (FAILED(m_pApp->m_pIDataObject->GetData(pFE, &stm))) 
        return; 
 
    //Get rid of old data and update. 
    ReleaseStgMedium(&(m_pApp->m_stm)); 
 
    m_pApp->m_cf=cf; 
    m_pApp->m_stm=stm; 
 
    InvalidateRect(m_pApp->m_hWnd, NULL, TRUE); 
 
    if (m_pApp->m_fRepaint) 
        UpdateWindow(m_pApp->m_hWnd); 
 
    return; 
    } 
 
 
 
 
/* 
 * CAdviseSink::OnViewChange 
 * CAdviseSink::OnRename 
 * CAdviseSink::OnSave 
 * CAdviseSink::OnClose 
 * 
 * Unimplemented members 
 */ 
 
STDMETHODIMP_(void) CAdviseSink::OnViewChange(DWORD dwAspect 
    , LONG lindex) 
    { 
    return; 
    } 
 
STDMETHODIMP_(void) CAdviseSink::OnRename(LPMONIKER pmk) 
    { 
    return; 
    } 
 
STDMETHODIMP_(void) CAdviseSink::OnSave(void) 
    { 
    return; 
    } 
 
STDMETHODIMP_(void) CAdviseSink::OnClose(void) 
    { 
    return; 
    }