basically finish dialog helper

src/DialogHelper.cpp

@@ -0,0 +1,162 @@
+#include "DialogHelper.hpp"
+#if YYCC_OS == YYCC_OS_WINDOWS
+
+#include "EncodingHelper.hpp"
+
+namespace YYCC::DialogHelper {
+
+	template<bool TIsOpen, bool TMultiSelection>
+	bool GeneralFileDialog(const FileDialogParameter& params, std::vector<std::string>& ret) {
+		// make sure multi-selection only available in open mode
+		static_assert(TIsOpen && (!TIsOpen && TMultiSelection == false));
+
+		// build filter
+		std::wstring w_filter;
+		for (const auto& filter_pair : params.m_Filter) {
+			w_filter += EncodingHelper::UTF8ToWchar(filter_pair.first.c_str());
+			w_filter += L'\0';
+			w_filter += EncodingHelper::UTF8ToWchar(filter_pair.second.c_str());
+			w_filter += L'\0';
+		}
+		// build title
+		std::wstring w_title(EncodingHelper::UTF8ToWchar(params.m_Title.c_str()));
+		// build default extension
+		std::wstring w_default_ext(EncodingHelper::UTF8ToWchar(params.m_DefaultExtension.c_str()));
+		// build initial directory
+		std::wstring w_init_dir(EncodingHelper::UTF8ToWchar(params.m_InitialDirectory.c_str()));
+		// prepare file name receiver and preset it as initial file name
+		std::wstring path_receiver(EncodingHelper::UTF8ToWchar(params.m_InitialFileName.c_str()));
+		path_receiver.resize(std::max(MAX_PATH, path_receiver.size()), L'\0');
+
+		// prepare the common part of file dialog struct
+		OPENFILENAMEW dialog_param;
+		ZeroMemory(&dialog_param, sizeof(OPENFILENAMEW));
+		dialog_param.lStructSize = sizeof(OPENFILENAMEW);
+		// dialog owner
+		dialog_param.hwndOwner = params.m_Owner;
+		// if no filter, we pass NULL
+		dialog_param.lpstrFilter = w_filter.empty() ? NULL : w_filter.c_str();
+		// no record to user selected filter
+		dialog_param.lpstrCustomFilter = NULL;
+		dialog_param.nMaxCustFilter = 0;
+		dialog_param.nFilterIndex = 0;
+		// path receiver, also is init filename
+		dialog_param.lpstrFile = path_receiver.data();
+		dialog_param.nMaxFile = static_caast<DWORD>(path_receiver.size());
+		// no selected file infos
+		dialog_param.lpstrFileTitle = NULL;
+		dialog_param.nMaxFileTitle = 0;
+		// initial directory
+		dialog_param.lpstrInitialDir = w_init_dir.empty() ? NULL : w_init_dir.c_str();
+		// dialog title
+		dialog_param.lpstrTitle = w_title.empty() ? NULL : w_title.c_str();
+		// setup basic flags
+		dialog_param.Flags = OFN_EXPLORER;
+		// default extension
+		dialog_param.lpstrDefExt = w_default_ext.empty() ? NULL : w_default_ext.c_str();
+
+		BOOL status;
+		if constexpr (TIsOpen) {
+			// multi-selection need add special multi-selection flags
+			if constexpr (TMultiSelection) {
+				dialog_param.Flags |= OFN_ALLOWMULTISELECT;
+			}
+
+			// call browser
+			status = GetOpenFileNameW(&dialog_param);
+
+			// only process result when success
+			if (status) {
+				if constexpr (TMultiSelection) {
+					// get directory part, copy from start to dialog param specified offset
+					std::wstring w_directory_part(path_receiver.c_str(), dialog_param.nFileOffset);
+					// get file names part one by one
+					size_t filename_cursor = dialog_param.nFileOffset;
+					while (path_receiver[filename_cursor] != L'\0') {
+						// init wstring from given offset
+						std::wstring w_filename_part(path_receiver.c_str() + filename_cursor);
+						// get eaten chars from result and increase to cursor
+						filename_cursor += w_filename_part.size() + 1u;
+						// combine 2 parts and insert into list
+						ret.emplace_back(u8string(EncodingHelper::WcharToUTF8(w_directory_part + w_filename_part)));
+					}
+				} else {
+					ret.emplace_back(u8string(EncodingHelper::WcharToUTF8(path_receiver.c_str())));
+				}
+			}
+
+		} else {
+			// call browser
+			status = GetSaveFileNameW(&dialog_param);
+
+			// only process result when success
+			if (status) {
+				ret.emplace_back(u8string(EncodingHelper::WcharToUTF8(path_receiver.c_str())));
+			}
+
+		}
+
+		// if failed, clear result
+		// and return result
+		if (!status) {
+			ret.clear();
+		}
+		return status == TRUE;
+	}
+
+	bool OpenFileDialog(const FileDialogParameter& params, std::string& ret) {
+		std::vector<std::string> cache;
+		bool isok = GeneralFileDialog<true, false>(params, cache);
+		if (isok) ret = cache.front();
+		return isok;
+	}
+	bool OpenMultipleFileDialog(const FileDialogParameter& params, std::vector<std::string>& ret) {
+		return GeneralFileDialog<true, true>(params, ret);
+	}
+	bool SaveFileDialog(const FileDialogParameter& params, std::string& ret) {
+		std::vector<std::string> cache;
+		bool isok = GeneralFileDialog<false, false>(params, cache);
+		if (isok) ret = cache.front();
+		return isok;
+	}
+
+	bool OpenFolderDialog(const FolderDialogParameter& params, std::string& ret) {
+		// create wchar string cache for windows W-tail function
+		std::wstring w_title(EncodingHelper::UTF8ToWchar(params.m_Title.c_str()));
+		// create buffer for receiving selected folder
+		// initialize with MAX_PATH length and content is filled with zero.
+		std::wstring path_receiver(MAX_PATH, L'\0');
+
+		// prepare folder foalog struct
+		BROWSEINFOW dialog_param = { 0 };
+		dialog_param.hwndOwner = params.m_Owner;
+		dialog_param.pidlRoot = nullptr;
+		dialog_param.pszDisplayName = path_receiver.data();
+		dialog_param.lpszTitle = w_title.c_str();
+		dialog_param.ulFlags = BIF_RETURNONLYFSDIRS | BIF_USENEWUI;
+		dialog_param.lpfn = nullptr;
+
+		// call browser
+		PIDLIST_ABSOLUTE place = SHBrowseForFolderW(&dialog_param);
+		// if browser failed, return.
+		if (place == nullptr) {
+			ret.clear();
+			return false;
+		}
+
+		// get path from browser result
+		BOOL status;
+		if (status = SHGetPathFromIDListW(place, path_receiver.data())) {
+			EncodingHelper::WcharToUTF8(path_receiver.c_str(), ret);
+		} else {
+			ret.clear();
+		}
+
+		// clear browser result and return
+		CoTaskMemFree(place);
+		return status == TRUE;
+	}
+
+}
+
+#endif