IENUMCON.CPP

/* 
 * IENUMCON.CPP 
 * 
 * Standard implementation of an enumerator with the 
 * IEnumConnections interface that will generally not need 
 * modification. 
 * 
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved 
 * 
 * Kraig Brockschmidt, Microsoft 
 * Internet  :  kraigb@microsoft.com 
 * Compuserve:  >INTERNET:kraigb@microsoft.com 
 */ 
 
 
#include "ienumcon.h" 
 
 
/* 
 * CEnumConnections::CEnumConnections 
 * CEnumConnections::~CEnumConnections 
 * 
 * Parameters (Constructor): 
 *  pUnkRef         LPUNKNOWN to use for reference counting. 
 *  cConn           ULONG number of connections in prgpConn 
 *  prgConnData     LPCONNECTDATA to the array to enumerate. 
 */ 
 
CEnumConnections::CEnumConnections(LPUNKNOWN pUnkRef, ULONG cConn 
    , LPCONNECTDATA prgConnData) 
    { 
    UINT        i; 
 
    m_cRef=0; 
    m_pUnkRef=pUnkRef; 
 
    m_iCur=0; 
    m_cConn=cConn; 
    m_rgConnData=new CONNECTDATA[(UINT)cConn]; 
 
    if (NULL!=m_rgConnData) 
        { 
        for (i=0; i < cConn; i++) 
            m_rgConnData[i]=prgConnData[i]; 
        } 
 
    return; 
    } 
 
 
CEnumConnections::~CEnumConnections(void) 
    { 
    if (NULL!=m_rgConnData) 
        delete [] m_rgConnData; 
 
    return; 
    } 
 
 
 
 
 
 
/* 
 * CEnumConnections::QueryInterface 
 * CEnumConnections::AddRef 
 * CEnumConnections::Release 
 * 
 * Purpose: 
 *  IUnknown members for CEnumConnections object. 
 */ 
 
STDMETHODIMP CEnumConnections::QueryInterface(REFIID riid 
    , LPVOID *ppv) 
    { 
    *ppv=NULL; 
 
    /* 
     * Enumerators are separate objects, so we only need to support 
     * ou IUnknown and IEnumConnections interfaces here with no 
     * concern for aggregation. 
     */ 
    if (IID_IUnknown==riid || IID_IEnumConnections==riid) 
        *ppv=(LPVOID)this; 
 
    if (NULL!=*ppv) 
        { 
        ((LPUNKNOWN)*ppv)->AddRef(); 
        return NOERROR; 
        } 
 
    return ResultFromScode(E_NOINTERFACE); 
    } 
 
 
STDMETHODIMP_(ULONG) CEnumConnections::AddRef(void) 
    { 
    ++m_cRef; 
    m_pUnkRef->AddRef(); 
    return m_cRef; 
    } 
 
STDMETHODIMP_(ULONG) CEnumConnections::Release(void) 
    { 
    m_pUnkRef->Release(); 
 
    if (0L!=--m_cRef) 
        return m_cRef; 
 
    delete this; 
    return 0; 
    } 
 
 
 
 
 
/* 
 * CEnumConnections::Next 
 * 
 * Purpose: 
 *  Returns the next element in the enumeration. 
 * 
 * Parameters: 
 *  cConn           ULONG number of connections to return. 
 *  pConnData       LPCONNECTDATA in which to store the returned 
 *                  structures. 
 *  pulEnum         ULONG * in which to return how many we 
 *                  enumerated. 
 * 
 * Return Value: 
 *  HRESULT         NOERROR if successful, S_FALSE otherwise, 
 */ 
 
STDMETHODIMP CEnumConnections::Next(ULONG cConn 
    , LPCONNECTDATA pConnData, ULONG *pulEnum) 
    { 
    ULONG               cReturn=0L; 
 
    if (NULL==m_rgConnData) 
        return ResultFromScode(S_FALSE); 
 
    if (NULL==pulEnum) 
        { 
        if (1L!=cConn) 
            return ResultFromScode(E_POINTER); 
        } 
    else 
        *pulEnum=0L; 
 
    if (NULL==pConnData || m_iCur >= m_cConn) 
        return ResultFromScode(S_FALSE); 
 
    while (m_iCur < m_cConn && cConn > 0) 
        { 
        *pConnData++=m_rgConnData[m_iCur]; 
        m_rgConnData[m_iCur++].pUnk->AddRef; 
        cReturn++; 
        cConn--; 
        } 
 
    if (NULL!=pulEnum) 
        *pulEnum=cReturn; 
 
    return NOERROR; 
    } 
 
 
 
 
 
 
 
/* 
 * CEnumConnections::Skip 
 * 
 * Purpose: 
 *  Skips the next n elements in the enumeration. 
 * 
 * Parameters: 
 *  cSkip           ULONG number of elements to skip. 
 * 
 * Return Value: 
 *  HRESULT         NOERROR if successful, S_FALSE if we could not 
 *                  skip the requested number. 
 */ 
 
STDMETHODIMP CEnumConnections::Skip(ULONG cSkip) 
    { 
    if (((m_iCur+cSkip) >= m_cConn) || NULL==m_rgConnData) 
        return ResultFromScode(S_FALSE); 
 
    m_iCur+=cSkip; 
    return NOERROR; 
    } 
 
 
 
 
 
 
/* 
 * CEnumConnections::Reset 
 * 
 * Purpose: 
 *  Resets the current element index in the enumeration to zero. 
 * 
 * Parameters: 
 *  None 
 */ 
 
STDMETHODIMP CEnumConnections::Reset(void) 
    { 
    m_iCur=0; 
    return NOERROR; 
    } 
 
 
 
 
 
 
/* 
 * CEnumConnections::Clone 
 * 
 * Purpose: 
 *  Returns another IEnumConnections with the same state as ourselves. 
 * 
 * Parameters: 
 *  ppEnum          LPENUMCONNECTIONPOINTS * in which to return the 
 *                  new object. 
 */ 
 
STDMETHODIMP CEnumConnections::Clone(LPENUMCONNECTIONS *ppEnum) 
    { 
    PCEnumConnections   pNew; 
 
    *ppEnum=NULL; 
 
    //Create the clone 
    pNew=new CEnumConnections(m_pUnkRef, m_cConn, m_rgConnData); 
 
    if (NULL==pNew) 
        return ResultFromScode(E_OUTOFMEMORY); 
 
    pNew->AddRef(); 
    pNew->m_iCur=m_iCur; 
 
    *ppEnum=pNew; 
    return NOERROR; 
    }