change the use of SHBrowseForFolder and struct BROWSEINFO TO - IFileOpenDialog - c++

Question

until now- in order to open a dialog box I used SHBrowseForFolder function. It causes some bugs and I was told to use IFileOpenDialog.
here is the code I need to replace:
bool wvFM::SelectFileSystemObjectDialogTree(const WCDialogCreationOptions& in_options,
WCDialogReply& out_Reply)
{
AUTO_FUNC_DEBUG;
DWORD osErr = NO_ERROR;
WTErr wtErr = eNoErr;
out_Reply.accept = false;
if(in_options.m_flags[WCDialogCreationOptions::eSelectFolder]) {
BROWSEINFO bi = {0};
bi.hwndOwner = (HWND)in_options.m_owner;
bi.pidlRoot = NULL; // TBD by callback BrowseCallbackProc
bi.lpszTitle = in_options.m_windowTitle.c_str();
bi.ulFlags = BIF_USENEWUI; // to enable pasting path
bi.lpfn = BrowseCallbackProc; // for initial dir option
WTPathString initialLocationPathString(
in_options.m_InitialDir.GetNativePathString());
bi.lParam = in_options.m_InitialDir.IsValid()
? (LPARAM)initialLocationPathString.c_str()
: NULL;
LPITEMIDLIST pidl = SHBrowseForFolder(&bi);
// returns focus to the internal window of the plug
::SetFocus((HWND)in_options.m_owner);
if(pidl != NULL) {
TCHAR szPath[MAX_PATH];
SHGetPathFromIDList(pidl, szPath);
out_Reply.m_filePathRef = wvFM::WCStPath((char*)szPath);
out_Reply.accept = true;
IMalloc* imalloc = 0;
if(SUCCEEDED(SHGetMalloc(&imalloc))) {
imalloc->Free(pidl);
imalloc->Release();
}
}
return true;
}
I am not so sure of how to make that conversion.
Thanks to anyone who will help!

Answer 1

You are clearly using a 3rd party library with some kind of custom string type, but you did not provide any details about what that string type actually is. I'm guessing that string type is char-based, given that you are type-casting the result of SHGetPathFromIDList() to char* when assigning it to out_Reply.m_filePathRef, so you are likely compiling your project with UNICODE undefined so that TCHAR maps to char and not wchar_t. In which case, SHBrowseForFolder() would be calling SHBrowseForFolderA() and not SHBrowseForFolderW().
IFileOpenDialog does not deal with ANSI strings at all, only UNICODE strings, so you will have to convert back and forth between your 3rd party string type and Windows UTF-16 strings as needed.
The conversion of SHBrowseForFolder() to IFileOpenDialog would look roughly like the following (where YourStringType in toWString() is the 3rd party string type - make whatever adjustments you need where indicated):
std::wstring toWString(const YourStringType &str)
{
const char pStr = ... pointer to str's characters ...;
int sLen = ... length of str in chars, not counting the null terminator ...;
std::wstring ws;
int wLen = MultiByteToWideChar(CP_ACP, 0, pStr, slen, NULL, 0);
if (wLen > 0)
{
ws.resize(wLen);
MultiByteToWideChar(CP_ACP, 0, pStr, sLen, ws.data(), wLen);
}
return ws;
}
std::string toString(const wchar_t *ws)
{
std::string s;
int wLen = lstrlenW(s);
int sLen = WideCharToMultiByte(CP_ACP, 0, ws, wLen, NULL, 0, NULL, NULL);
if (sLen > 0)
{
s.resize(sLen);
WideCharToMultiByte(CP_ACP, 0, ws, wLen, s.data(), sLen, NULL, NULL);
}
return s;
}
IShellItem* toShellItem(const YourStringType &path)
{
IShellItem *pItem = NULL;
if (FAILED(SHCreateItemFromParsingName(toWString(path).c_str(), NULL, IID_PPV_ARGS(&pItem))))
pItem = NULL;
return pItem;
}
bool wvFM::SelectFileSystemObjectDialogTree(const WCDialogCreationOptions& in_options,
WCDialogReply& out_Reply)
{
AUTO_FUNC_DEBUG;
out_Reply.accept = false;
if (in_options.m_flags[WCDialogCreationOptions::eSelectFolder]) {
IFileOpenDialog *pFileOpen = NULL;
if (FAILED(CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_ALL, IID_PPV_ARGS(&pFileOpen))))
return false;
FILEOPENDIALOGOPTIONS opts = 0;
pFileOpen->GetOptions(&opts);
pFileOpen->SetTitle(toWString(in_options.m_windowTitle).c_str());
pFileOpen->SetOptions(opts | FOS_PICKFOLDERS);
IShellItem *pItem = toShellItem(in_options.m_InitialDir);
if (pItem)
{
pFileOpen->SetFolder(pItem);
pItem->Release();
}
HWND hwndOwner = (HWND) in_options.m_owner;
HRESULT hr = pFileOpen->Show(hwndOwner);
::SetFocus(hwndOwner);
if (SUCCEEDED(hr))
{
if (SUCCEEDED(pFileOpen->GetResult(&pItem)))
{
PWSTR pszFilePath;
if (SUCCEEDED(pItem->GetDisplayName(SIGDN_FILESYSPATH, &pszFilePath)))
{
out_Reply.m_filePathRef = wvFM::WCStPath(toString(pszFilePath).c_str());
out_Reply.accept = true;
CoTaskMemFree(pszFilePath);
}
pItem->Release();
}
}
pFileOpen->Release();
return true;
}
...
}