HRESULT PreviewGenerator::ShowPreviewWithShellItemImageFactory(CString filePath)
{
HRESULT hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
IShellItemImageFactory *imageFactory;
hr = SHCreateItemFromParsingName(filePath, NULL, IID_PPV_ARGS(&imageFactory));
if (hr == S_OK)
{
CRect pRect;
previewControl->GetWindowRect(pRect);
int s = pRect.Height();
if (s>pRect.Width())
s = pRect.Width();
//s = 256;
_SIIGBF flag = SIIGBF_RESIZETOFIT;
if (fileExt != L"pdf" && fileExt != L"PDF")
{
s = 256;
flag = SIIGBF_BIGGERSIZEOK;
}
SIZE size = { s, s };
HBITMAP btmap;
hr = imageFactory->GetImage(size, flag, &btmap);
if (hr == S_OK)
DrawBitMap(btmap);
}
CoUninitialize();
imageFactory->Release();
return hr;
}
// On Vista or 7 we could use SHIL_JUMBO to get a 256x256 icon,
// but we'll use SHCreateItemFromParsingName as it'll give an identical
// icon to the one shown in explorer and it scales automatically.
bool WinIconProvider::addIconFromShellFactory(QString filePath, QIcon& icon) const
{
HRESULT hr = S_FALSE;
if (fnSHCreateItemFromParsingName)
{
IShellItem* psi = NULL;
hr = fnSHCreateItemFromParsingName((PCWSTR)filePath.utf16(), 0, IID_IShellItem, (void**)&psi);
if (hr == S_OK)
{
IShellItemImageFactory* psiif = NULL;
hr = psi->QueryInterface(IID_IShellItemImageFactory, (void**)&psiif);
if (hr == S_OK)
{
HBITMAP iconBitmap = NULL;
SIZE iconSize = {preferredSize, preferredSize};
hr = psiif->GetImage(iconSize, SIIGBF_RESIZETOFIT | SIIGBF_ICONONLY, &iconBitmap);
if (hr == S_OK)
{
QPixmap iconPixmap = QtWin::fromHBITMAP(iconBitmap);
icon.addPixmap(iconPixmap);
DeleteObject(iconBitmap);
}
psiif->Release();
}
psi->Release();
}
}
return hr == S_OK;
}
