139 lines
3.6 KiB
C++
139 lines
3.6 KiB
C++
/*--------------------------------------------------------------------------*
|
|
*
|
|
* Microsoft Windows
|
|
* Copyright (C) Microsoft Corporation, 1992 - 000
|
|
*
|
|
* File: guidhelp.inl
|
|
*
|
|
* Contents:
|
|
*
|
|
* History: 13-Apr-2000 jeffro Created
|
|
*
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
#pragma once
|
|
|
|
#include "xmlbase.h" // for CXMLBinary
|
|
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
* ExtractString
|
|
*
|
|
* Gets string data representing the given clipboard format from the data
|
|
* object. StringType must be a type that can accept assignment from
|
|
* LPCTSTR (WTL::CString, CStr, tstring, etc.)
|
|
*
|
|
* Many (many!) implementations of IDataObject::GetDataHere incorrectly call
|
|
* CreateStreamOnHGlobal using the HGLOBAL we get them (calling it is
|
|
* incorrect because GetDataHere is specifically forbidden from reallocating
|
|
* the medium that is given to it, which the IStream implementation returned
|
|
* from CreateStreamOnHGlobal will do if it needs more room).
|
|
*
|
|
* We would be more robust if we used TYMED_STREAM in preference to
|
|
* TYMED_HGLOBAL, if the snap-in supported it.
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
template<class StringType>
|
|
HRESULT ExtractString (
|
|
IDataObject* piDataObject,
|
|
CLIPFORMAT cfClipFormat,
|
|
StringType& str)
|
|
{
|
|
DECLARE_SC (sc, _T("ExtractString"));
|
|
|
|
sc = ScCheckPointers (piDataObject);
|
|
if (sc)
|
|
return (sc.ToHr());
|
|
|
|
/*
|
|
* clear out the output
|
|
*/
|
|
str = _T("");
|
|
|
|
FORMATETC formatetc = {cfClipFormat, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL};
|
|
STGMEDIUM stgmedium = {TYMED_HGLOBAL, NULL};
|
|
CXMLBinary xmlBin;
|
|
|
|
/*
|
|
* 1024 isn't a random number. It must be (at least) this large to
|
|
* maintain compatibility with buggy snap-ins.
|
|
*/
|
|
const int cchGrow = 1024;
|
|
int cchBuffer = 0;
|
|
|
|
/*
|
|
* to enter the loop the first time
|
|
*/
|
|
sc = STG_E_MEDIUMFULL;
|
|
|
|
while (sc == STG_E_MEDIUMFULL)
|
|
{
|
|
/*
|
|
* increase the buffer size
|
|
*/
|
|
cchBuffer += cchGrow;
|
|
const int cbBuffer = cchBuffer * sizeof(WCHAR);
|
|
|
|
/*
|
|
* Allocate a buffer for the string. In the reallocation case,
|
|
* it is safe to store the return value from GlobalReAlloc in
|
|
* stgmedium.hGlobal because the original handle is also held
|
|
* in autoGlobal
|
|
*/
|
|
if (cchBuffer == cchGrow)
|
|
sc = xmlBin.ScAlloc (cbBuffer, true /* fZeroInit */);
|
|
else
|
|
sc = xmlBin.ScRealloc (cbBuffer, true /* fZeroInit */);
|
|
|
|
if (sc)
|
|
return (sc.ToHr());
|
|
|
|
/*
|
|
* get the HGLOBAL out of the CXMLBinary
|
|
*/
|
|
stgmedium.hGlobal = xmlBin.GetHandle();
|
|
sc = ScCheckPointers (stgmedium.hGlobal, E_UNEXPECTED);
|
|
if (sc)
|
|
return (sc.ToHr());
|
|
|
|
/*
|
|
* get the string from the data object
|
|
*/
|
|
sc = piDataObject->GetDataHere (&formatetc, &stgmedium);
|
|
// don't check for error here, it'll be checked at the top of the loop
|
|
}
|
|
|
|
/*
|
|
* this will handle all non-STG_E_MEDIUMFULL errors from
|
|
* IDataObject::GetDataHere
|
|
*/
|
|
if (sc)
|
|
{
|
|
// don't trace these errors
|
|
SC scTemp = sc;
|
|
sc.Clear();
|
|
return scTemp.ToHr();
|
|
}
|
|
|
|
/*
|
|
* lock down the returned data in preparation for copying
|
|
*/
|
|
CXMLBinaryLock lock (xmlBin);
|
|
|
|
LPWSTR pchBuffer = NULL;
|
|
sc = lock.ScLock (&pchBuffer);
|
|
if (sc)
|
|
return (sc.ToHr());
|
|
|
|
/*
|
|
* Copy the string. The termination isn't unjustified paranoia.
|
|
* Many implementations of IDataObject::GetDataHere don't terminate
|
|
* their strings.
|
|
*/
|
|
USES_CONVERSION;
|
|
pchBuffer[cchBuffer-1] = 0;
|
|
str = W2CT (pchBuffer);
|
|
|
|
return (sc.ToHr());
|
|
}
|