windows-nt/Source/XPSP1/NT/admin/activec/samples/sdksamples/cmenuext/cmenuext.cpp

//==============================================================;
//
//  This source code is only intended as a supplement to existing Microsoft documentation. 
//
// 
//
//
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
//  PURPOSE.
//
//  Copyright (C) 1999 Microsoft Corporation.  All Rights Reserved.
//
//
//
//==============================================================;

#include "CMenuExt.h"
#include "globals.h"
#include "resource.h"
#include <crtdbg.h>

// we need to do this to get around MMC.IDL - it explicitly defines
// the clipboard formats as WCHAR types...
#define _T_CCF_DISPLAY_NAME _T("CCF_DISPLAY_NAME")
#define _T_CCF_NODETYPE _T("CCF_NODETYPE")
#define _T_CCF_SNAPIN_CLASSID _T("CCF_SNAPIN_CLASSID")

// These are the clipboard formats that we must supply at a minimum.
// mmc.h actually defined these. We can make up our own to use for
// other reasons. We don't need any others at this time.
UINT CContextMenuExtension::s_cfDisplayName = RegisterClipboardFormat(_T_CCF_DISPLAY_NAME);
UINT CContextMenuExtension::s_cfNodeType    = RegisterClipboardFormat(_T_CCF_NODETYPE);
UINT CContextMenuExtension::s_cfSnapInCLSID = RegisterClipboardFormat(_T_CCF_SNAPIN_CLASSID);

CContextMenuExtension::CContextMenuExtension() : m_cref(0)
{
    OBJECT_CREATED
}

CContextMenuExtension::~CContextMenuExtension()
{
    OBJECT_DESTROYED
}

///////////////////////
// IUnknown implementation
///////////////////////

STDMETHODIMP CContextMenuExtension::QueryInterface(REFIID riid, LPVOID *ppv)
{
    if (!ppv)
        return E_FAIL;
    
    *ppv = NULL;
    
    if (IsEqualIID(riid, IID_IUnknown))
        *ppv = static_cast<IExtendContextMenu *>(this);
    else if (IsEqualIID(riid, IID_IExtendContextMenu))
        *ppv = static_cast<IExtendContextMenu *>(this);
    
    if (*ppv) 
    {
        reinterpret_cast<IUnknown *>(*ppv)->AddRef();
        return S_OK;
    }
    
    return E_NOINTERFACE;
}

STDMETHODIMP_(ULONG) CContextMenuExtension::AddRef()
{
    return InterlockedIncrement((LONG *)&m_cref);
}

STDMETHODIMP_(ULONG) CContextMenuExtension::Release()
{
    if (InterlockedDecrement((LONG *)&m_cref) == 0)
    {
        // we need to decrement our object count in the DLL
        delete this;
        return 0;
    }
    
    return m_cref;
}

HRESULT CContextMenuExtension::ExtractData( IDataObject* piDataObject,
                                           CLIPFORMAT   cfClipFormat,
                                           BYTE*        pbData,
                                           DWORD        cbData )
{
    HRESULT hr = S_OK;
    
    FORMATETC formatetc = {cfClipFormat, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL};
    STGMEDIUM stgmedium = {TYMED_HGLOBAL, NULL};
    
    stgmedium.hGlobal = ::GlobalAlloc(GPTR, cbData);
    do // false loop
    {
        if (NULL == stgmedium.hGlobal)
        {
            hr = E_OUTOFMEMORY;
            break;
        }
        hr = piDataObject->GetDataHere( &formatetc, &stgmedium );
        if ( FAILED(hr) )
        {
            break;
        }
        
        BYTE* pbNewData = reinterpret_cast<BYTE*>(stgmedium.hGlobal);
        if (NULL == pbNewData)
        {
            hr = E_UNEXPECTED;
            break;
        }
        ::memcpy( pbData, pbNewData, cbData );
    } while (FALSE); // false loop
    
    if (NULL != stgmedium.hGlobal)
    {
        ::GlobalFree(stgmedium.hGlobal);
    }
    return hr;
} // ExtractData()

HRESULT CContextMenuExtension::ExtractString( IDataObject *piDataObject,
                                             CLIPFORMAT   cfClipFormat,
                                             WCHAR        *pstr,
                                             DWORD        cchMaxLength)
{
    return ExtractData( piDataObject, cfClipFormat, (PBYTE)pstr, cchMaxLength );
}

HRESULT CContextMenuExtension::ExtractSnapInCLSID( IDataObject* piDataObject, CLSID* pclsidSnapin )
{
    return ExtractData( piDataObject, s_cfSnapInCLSID, (PBYTE)pclsidSnapin, sizeof(CLSID) );
}

HRESULT CContextMenuExtension::ExtractObjectTypeGUID( IDataObject* piDataObject, GUID* pguidObjectType )
{
    return ExtractData( piDataObject, s_cfNodeType, (PBYTE)pguidObjectType, sizeof(GUID) );
}

///////////////////////////////
// Interface IExtendContextMenu
///////////////////////////////
HRESULT CContextMenuExtension::AddMenuItems( 
                                            /* [in] */ LPDATAOBJECT piDataObject,
                                            /* [in] */ LPCONTEXTMENUCALLBACK piCallback,
                                            /* [out][in] */ long __RPC_FAR *pInsertionAllowed)
{
    HRESULT hr = S_OK;
    CONTEXTMENUITEM menuItemsTask[] =
    {
        {
            L"People Extension", L"Do an extension thing",
                1, CCM_INSERTIONPOINTID_3RDPARTY_TASK  , 0, 0
        },
        { NULL, NULL, 0, 0, 0 }
    };
    
    // Loop through and add each of the menu items
    if (*pInsertionAllowed & CCM_INSERTIONALLOWED_TASK)
    {
        for (CONTEXTMENUITEM *m = menuItemsTask; m->strName; m++)
        {
            hr = piCallback->AddItem(m);
            
            if (FAILED(hr))
                break;
        }
    }
    
    return hr;
    
}

HRESULT CContextMenuExtension::Command( 
                                       /* [in] */ long lCommandID,
                                       /* [in] */ LPDATAOBJECT piDataObject)
{
    WCHAR pszName[255];
    HRESULT hr = ExtractString(piDataObject, s_cfDisplayName, pszName, sizeof(pszName));
    MAKE_TSTRPTR_FROMWIDE(ptrname, pszName);
    
    if (SUCCEEDED(hr)) {
        switch (lCommandID)
        {
        case 1:
            ::MessageBox(NULL, ptrname, _T("Menu Command"), MB_OK|MB_ICONEXCLAMATION);
            break;
        }
    }
    
    return hr;
}