feat: add some dialog code which can not work now.

- add common file dialog showcase code but all of them are not work now.

src/DialogHelper.cpp

@@ -69,9 +69,219 @@ namespace YYCC::DialogHelper {
 
 #pragma endregion
 
-#pragma region FileDialog
+#pragma region File Dialog
 
+	bool FileDialog::Generate(WinFileDialog& win_result) const {
+		return false;
+	}
 
+#pragma endregion
+
+#pragma region Windows Dialog Code
+
+	enum class CommonFileDialogType {
+		OpenFile,
+		OpenMultipleFiles,
+		SaveFile,
+		OpenFolder
+	};
+
+	using SmartFileDialogPtr = std::unique_ptr<IFileDialog, std::function<void(IFileDialog*)>>;
+
+	template<CommonFileDialogType EDialogType>
+	bool CommonFileDialog(const FileDialog& params, std::vector<std::string>& ret) {
+		// Reference: https://learn.microsoft.com/en-us/windows/win32/shell/common-file-dialog
+		// prepare result variable
+		HRESULT hr;
+
+		// create file dialog instance
+		// fetch dialog CLSID first
+		CLSID dialog_clsid;
+		switch (EDialogType) {
+			case CommonFileDialogType::OpenFile:
+			case CommonFileDialogType::OpenMultipleFiles:
+			case CommonFileDialogType::OpenFolder:
+				dialog_clsid = CLSID_FileOpenDialog;
+				break;
+			case CommonFileDialogType::SaveFile:
+				dialog_clsid = CLSID_FileSaveDialog;
+				break;
+			default:
+				return false;
+		}
+		// create raw dialog pointer
+		IFileDialog* _pfd = nullptr;
+		hr = CoCreateInstance(
+			dialog_clsid,
+			NULL,
+			CLSCTX_INPROC_SERVER,
+			IID_PPV_ARGS(&_pfd)
+		);
+		if (!SUCCEEDED(hr)) return false;
+		// create memory-safe dialog pointer
+		SmartFileDialogPtr pfd(
+			_pfd,
+			[](IFileDialog* instance) -> void {
+				if (instance != nullptr)
+					instance->Release();
+			}
+		);
+
+		// set options for dialog
+		// before setting, always get the options first in order.
+		// not to override existing options.
+		DWORD dwFlags;
+		hr = pfd->GetOptions(&dwFlags);
+		if (!SUCCEEDED(hr)) return false;
+		// modify options
+		switch (EDialogType) {
+			// We want user only can pick file system files: FOS_FORCEFILESYSTEM.
+			// Open dialog default: FOS_PATHMUSTEXIST | FOS_FILEMUSTEXIST | FOS_NOCHANGEDIR
+			// Save dialog default: FOS_OVERWRITEPROMPT | FOS_NOREADONLYRETURN | FOS_PATHMUSTEXIST | FOS_NOCHANGEDIR
+			// Pick folder: FOS_PICKFOLDERS
+			case CommonFileDialogType::OpenFile:
+				dwFlags |= FOS_FORCEFILESYSTEM;
+				dwFlags |= FOS_PATHMUSTEXIST | FOS_FILEMUSTEXIST | FOS_NOCHANGEDIR;
+				break;
+			case CommonFileDialogType::OpenMultipleFiles:
+				dwFlags |= FOS_FORCEFILESYSTEM;
+				dwFlags |= FOS_PATHMUSTEXIST | FOS_FILEMUSTEXIST | FOS_NOCHANGEDIR;
+				dwFlags |= FOS_ALLOWMULTISELECT;
+				break;
+			case CommonFileDialogType::SaveFile:
+				dwFlags |= FOS_FORCEFILESYSTEM;
+				dwFlags |= FOS_OVERWRITEPROMPT | FOS_NOREADONLYRETURN | FOS_PATHMUSTEXIST | FOS_NOCHANGEDIR;
+				break;
+			case CommonFileDialogType::OpenFolder:
+				dwFlags |= FOS_FORCEFILESYSTEM;
+				dwFlags |= FOS_PATHMUSTEXIST | FOS_FILEMUSTEXIST | FOS_NOCHANGEDIR;
+				dwFlags |= FOS_PICKFOLDERS;
+				break;
+			default:
+				return false;
+		}
+		// set folder dialog options
+		hr = pfd->SetOptions(dwFlags);
+		if (!SUCCEEDED(hr)) return false;
+
+		// set title
+		std::wstring wtitle, winit_filename, winit_directory;
+		if (params.GetTitle() != nullptr) {
+			EncodingHelper::UTF8ToWchar(params.GetTitle(), wtitle);
+		}
+
+		// set file types and default file index when we picking file
+		WinFileFilters win_file_filters;
+		if constexpr (EDialogType != CommonFileDialogType::OpenFolder) {
+			// generate data from user specified file filters
+			const auto& file_filters = params.GetFileTypes();
+			if (!file_filters.Generate(win_file_filters))
+				return false;
+
+			// set file types list
+			hr = pfd->SetFileTypes(win_file_filters.GetFilterCount(), win_file_filters.GetFilterSpecs());
+			if (!SUCCEEDED(hr)) return false;
+
+			// set default file type index
+			// Windows order this is 1-based index.
+			// We plus 1 for it because we used is 0-based index.
+			hr = pfd->SetFileTypeIndex(params.GetDefaultFileTypeIndex() + 1);
+			if (!SUCCEEDED(hr)) return false;
+		}
+
+		// CoCreate the File Open Dialog object.
+		IFileDialog* pfd = NULL;
+		HRESULT hr = CoCreateInstance(
+			CLSID_FileOpenDialog,
+			NULL,
+			CLSCTX_INPROC_SERVER,
+			IID_PPV_ARGS(&pfd)
+		);
+		if (SUCCEEDED(hr)) {
+			// Set the options on the dialog.
+			DWORD dwFlags;
+
+			// Before setting, always get the options first in order 
+			// not to override existing options.
+			hr = pfd->GetOptions(&dwFlags);
+			if (SUCCEEDED(hr)) {
+				// In this case, get shell items only for file system items.
+				hr = pfd->SetOptions(dwFlags | FOS_FORCEFILESYSTEM);
+				if (SUCCEEDED(hr)) {
+					// Set the file types to display only. 
+					// Notice that this is a 1-based array.
+					hr = pfd->SetFileTypes(ARRAYSIZE(c_rgSaveTypes), c_rgSaveTypes);
+					if (SUCCEEDED(hr)) {
+						// Set the selected file type index to Word Docs for this example.
+						hr = pfd->SetFileTypeIndex(INDEX_WORDDOC);
+						if (SUCCEEDED(hr)) {
+							// Set the default extension to be ".doc" file.
+							hr = pfd->SetDefaultExtension(L"doc;docx");
+							if (SUCCEEDED(hr)) {
+								// Show the dialog
+								hr = pfd->Show(NULL);
+								if (SUCCEEDED(hr)) {
+									// Obtain the result once the user clicks 
+									// the 'Open' button.
+									// The result is an IShellItem object.
+									IShellItem* psiResult;
+									hr = pfd->GetResult(&psiResult);
+									if (SUCCEEDED(hr)) {
+										// We are just going to print out the 
+										// name of the file for sample sake.
+										PWSTR pszFilePath = NULL;
+										hr = psiResult->GetDisplayName(SIGDN_FILESYSPATH,
+											&pszFilePath);
+										if (SUCCEEDED(hr)) {
+											TaskDialog(NULL,
+												NULL,
+												L"CommonFileDialogApp",
+												pszFilePath,
+												NULL,
+												TDCBF_OK_BUTTON,
+												TD_INFORMATION_ICON,
+												NULL);
+											CoTaskMemFree(pszFilePath);
+										}
+										psiResult->Release();
+									}
+								}
+							}
+						}
+					}
+				}
+			}
+			pfd->Release();
+		}
+		return SUCCEEDED(hr);
+	}
+
+#pragma endregion
+
+#pragma region Wrapper Functions
+
+	bool OpenFileDialog(const FileDialog& params, std::string& ret) {
+		std::vector<std::string> cache;
+		bool isok = CommonFileDialog<CommonFileDialogType::OpenFile>(params, cache);
+		if (isok) ret = cache.front();
+		return isok;
+	}
+	bool OpenMultipleFileDialog(const FileDialog& params, std::vector<std::string>& ret) {
+		return CommonFileDialog<CommonFileDialogType::OpenMultipleFiles>(params, ret);
+	}
+	bool SaveFileDialog(const FileDialog& params, std::string& ret) {
+		std::vector<std::string> cache;
+		bool isok = CommonFileDialog<CommonFileDialogType::SaveFile>(params, cache);
+		if (isok) ret = cache.front();
+		return isok;
+	}
+
+	bool OpenFolderDialog(const FileDialog& params, std::string& ret) {
+		std::vector<std::string> cache;
+		bool isok = CommonFileDialog<CommonFileDialogType::OpenFolder>(params, cache);
+		if (isok) ret = cache.front();
+		return isok;
+	}
 
 #pragma endregion
 

src/DialogHelper.hpp

@@ -47,7 +47,7 @@ namespace YYCC::DialogHelper {
 	*/
 	class FileFilters {
 	public:
-		FileFilters() : m_Filters(){}
+		FileFilters() : m_Filters() {}
 
 		/**
 		 * @brief Add a filter pair in file types list.
@@ -86,6 +86,39 @@ namespace YYCC::DialogHelper {
 		std::vector<FilterPair> m_Filters;
 	};
 
+	class WinFileDialog {
+		friend class FileDialog;
+	public:
+		WinFileDialog() :
+			m_WinOwner(NULL),
+			m_WinFileTypes(), m_WinDefaultFileTypeIndex(0u),
+			m_HasTitle(false), m_HasInitFileName(false), m_WinTitle(), m_WinInitFileName(), 
+			m_WinInitDirectory(nullptr)
+		{}
+
+		bool HasOwner() const { return m_WinOwner != NULL; }
+		HWND GetOwner() const { return m_WinOwner; }
+
+		bool HasTitle() const { return !m_WinTitle.empty(); }
+		const wchar_t* GetTitle() const { return m_WinTitle.c_str(); }
+		bool HasInitFileName() const { return !m_WinInitFileName.empty(); }
+		const wchar_t* GetInitFileName() const { return m_WinInitFileName.c_str(); }
+		bool HasInitDirectory() const { return m_WinInitDirectory != nullptr;}
+		const IShellItem* GetInitDirectory() const { return m_WinInitDirectory.get(); }
+
+	protected:
+		HWND m_WinOwner;
+
+		WinFileFilters m_WinFileTypes;
+		UINT m_WinDefaultFileTypeIndex;
+
+		bool m_HasTitle, m_HasInitFileName;
+		std::wstring m_WinTitle, m_WinInitFileName;
+
+		using SmartShellItem = std::unique_ptr<IShellItem, std::function<void(IShellItem*)>>;
+		SmartShellItem m_WinInitDirectory;
+	};
+
 	class FileDialog {
 	public:
 		FileDialog() :
@@ -95,52 +128,38 @@ namespace YYCC::DialogHelper {
 			m_InitFileName(), m_InitDirectory() {}
 
 		void SetOwner(HWND owner) { m_Owner = owner; }
-		HWND GetOwner() const { return m_Owner; }
-
 		void SetTitle(const char* title) {
-			if (title == nullptr) m_Title.clear();
+			if (m_HasTitle = title != nullptr)
-			else m_Title = title;
+				m_Title = title;
 		}
-		const char* GetTitle() const {
+		FileFilters& ConfigreFileTypes() {
-			if (m_Title.empty()) return nullptr;
-			else return m_Title.c_str();
-		}
-
-		FileFilters& GetFileTypes() {
 			return m_FileTypes;
 		}
-		const FileFilters& GetFileTypes() const {
-			return m_FileTypes;
-		}
-
 		void SetDefaultFileTypeIndex(UINT idx) { m_DefaultFileTypeIndex = idx; }
-		UINT GetDefaultFileTypeIndex() const { return m_DefaultFileTypeIndex; }
-		
 		void SetInitFileName(const char* init_filename) {
-			if (init_filename == nullptr) m_InitFileName.clear();
+			if (m_HasInitFileName = init_filename != nullptr)
-			else m_InitFileName = init_filename;
+				m_InitFileName = init_filename;
 		}
-		const char* GetInitFileName() const {
-			if (m_InitFileName.empty()) return nullptr;
-			else return m_InitFileName.c_str();
-		}
-		
 		void SetInitDirectory(const char* init_dir) {
-			if (init_dir == nullptr) m_InitDirectory.clear();
+			if (m_HasInitDirectory = init_dir != nullptr)
-			else m_InitDirectory = init_dir;
+				m_InitDirectory = init_dir;
-		}
-		const char* GetInitDirectory() const {
-			if (m_InitDirectory.empty()) return nullptr;
-			else return m_InitDirectory.c_str();
 		}
 
-	private:
+		bool Generate(WinFileDialog& win_result) const;
+
+	protected:
 		HWND m_Owner;
-		std::string m_Title;
+
+		bool m_HasTitle, m_HasInitFileName, m_HasInitDirectory;
+		std::string m_Title, m_InitFileName, m_InitDirectory;
+
 		FileFilters m_FileTypes;
+		/**
+		 * @brief The default file type selected in dialog
+		 * @remarks Although Windows notice that this is a 1-based index,
+		 * but for universal experience, we order this is 0-based index.
+		*/
 		UINT m_DefaultFileTypeIndex;
-		std::string m_InitFileName;
-		std::string m_InitDirectory;
 	};
 
 	bool OpenFileDialog(const FileDialog& params, std::string& ret);