Image Tip - A popup thumbnail shell extension

// Image_Tip.cpp : Implementation of CImage_Tip
#include "stdafx.h"
#include "ImageTip.h"
#include "Image_Tip.h"

#include "GraphicTip.h"

/////////////////////////////////////////////////////////////////////////////
// CImage_Tip


HRESULT CImage_Tip::Load ( LPCOLESTR wszFilename, DWORD dwMode )
{
	m_FileName = wszFilename;

//	wchar_t	buf [512];
//	wcscpy (buf, L"CImage_Tip::Load ( '");
//	wcscat (buf, wszFilename);
//	wcscat (buf, L"' )\n");
//	OutputDebugStringW (buf);
	
    return S_OK;
}
 
HRESULT CImage_Tip::GetInfoTip ( DWORD   dwFlags, LPWSTR* ppwszTip )
{
	static std::wstring	m_FileNameLast;

	// We're going to create our own tooltipesque window, but with a the CPreviewBitmap in it...
//	wchar_t	buf [512];
//	wcscpy (buf, L"CImage_Tip::GetInfoTip (). m_Filename = '");
//	wcscat (buf, m_FileName.c_str ());
//	wcscat (buf, L"' m_FileNameLast = '");
//	wcscat (buf, m_FileNameLast.c_str ());
//	wcscat (buf, L"'\n");
//	OutputDebugStringW (buf);

	// Return a blank tooltip.
	IMalloc *pMalloc;
	if ( FAILED( SHGetMalloc ( &pMalloc )))
		return E_FAIL;
	*ppwszTip = (LPWSTR) pMalloc->Alloc ( (1) * sizeof(wchar_t) );
	if ( NULL == *ppwszTip )
	{
		pMalloc->Release();
		return E_OUTOFMEMORY;
	}
	(*ppwszTip) [0] = 0;
	pMalloc->Release();

	// Make sure we haven't recently shown this item, otherwise Explorer will keep on trying...
	if (m_FileName.compare (m_FileNameLast))
		CGraphicTip::ShowTip (m_FileName);	// This is all that's needed here!

	m_FileNameLast.erase ();
	m_FileNameLast.append (m_FileName);
	
	return S_OK;
}