SDL/include/SDL3/SDL_dialog.h

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/**
 * # CategoryDialog
 *
 * File dialog support.
 *
 * SDL offers file dialogs, to let users select files with native GUI
 * interfaces. There are "open" dialogs, "save" dialogs, and folder selection
 * dialogs. The app can control some details, such as filtering to specific
 * files, or whether multiple files can be selected by the user.
 *
 * Note that launching a file dialog is a non-blocking operation; control
 * returns to the app immediately, and a callback is called later (possibly in
 * another thread) when the user makes a choice.
 */

#ifndef SDL_dialog_h_
#define SDL_dialog_h_

#include <SDL3/SDL_stdinc.h>
#include <SDL3/SDL_error.h>
#include <SDL3/SDL_properties.h>
#include <SDL3/SDL_video.h>

#include <SDL3/SDL_begin_code.h>
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/**
 * An entry for filters for file dialogs.
 *
 * `name` is a user-readable label for the filter (for example, "Office
 * document").
 *
 * `pattern` is a semicolon-separated list of file extensions (for example,
 * "doc;docx"). File extensions may only contain alphanumeric characters,
 * hyphens, underscores and periods. Alternatively, the whole string can be a
 * single asterisk ("*"), which serves as an "All files" filter.
 *
 * \since This struct is available since SDL 3.1.3.
 *
 * \sa SDL_DialogFileCallback
 * \sa SDL_ShowOpenFileDialog
 * \sa SDL_ShowSaveFileDialog
 * \sa SDL_ShowOpenFolderDialog
 * \sa SDL_ShowFileDialogWithProperties
 */
typedef struct SDL_DialogFileFilter
{
    const char *name;
    const char *pattern;
} SDL_DialogFileFilter;

/**
 * Callback used by file dialog functions.
 *
 * The specific usage is described in each function.
 *
 * If `filelist` is:
 *
 * - NULL, an error occurred. Details can be obtained with SDL_GetError().
 * - A pointer to NULL, the user either didn't choose any file or canceled the
 *   dialog.
 * - A pointer to non-`NULL`, the user chose one or more files. The argument
 *   is a null-terminated list of pointers to C strings, each containing a
 *   path.
 *
 * The filelist argument should not be freed; it will automatically be freed
 * when the callback returns.
 *
 * The filter argument is the index of the filter that was selected, or -1 if
 * no filter was selected or if the platform or method doesn't support
 * fetching the selected filter.
 *
 * \param userdata an app-provided pointer, for the callback's use.
 * \param filelist the file(s) chosen by the user.
 * \param filter index of the selected filter.
 *
 * \since This datatype is available since SDL 3.1.3.
 *
 * \sa SDL_DialogFileFilter
 * \sa SDL_ShowOpenFileDialog
 * \sa SDL_ShowSaveFileDialog
 * \sa SDL_ShowOpenFolderDialog
 * \sa SDL_ShowFileDialogWithProperties
 */
typedef void (SDLCALL *SDL_DialogFileCallback)(void *userdata, const char * const *filelist, int filter);

/**
 * Displays a dialog that lets the user select a file on their filesystem.
 *
 * This is an asynchronous function; it will return immediately, and the
 * result will be passed to the callback.
 *
 * The callback will be invoked with a null-terminated list of files the user
 * chose. The list will be empty if the user canceled the dialog, and it will
 * be NULL if an error occurred.
 *
 * Note that the callback may be called from a different thread than the one
 * the function was invoked on.
 *
 * Depending on the platform, the user may be allowed to input paths that
 * don't yet exist.
 *
 * On Linux, dialogs may require XDG Portals, which requires DBus, which
 * requires an event-handling loop. Apps that do not use SDL to handle events
 * should add a call to SDL_PumpEvents in their main loop.
 *
 * \param callback a function pointer to be invoked when the user selects a
 *                 file and accepts, or cancels the dialog, or an error
 *                 occurs.
 * \param userdata an optional pointer to pass extra data to the callback when
 *                 it will be invoked.
 * \param window the window that the dialog should be modal for, may be NULL.
 *               Not all platforms support this option.
 * \param filters a list of filters, may be NULL. Not all platforms support
 *                this option, and platforms that do support it may allow the
 *                user to ignore the filters. If non-NULL, it must remain
 *                valid at least until the callback is invoked.
 * \param nfilters the number of filters. Ignored if filters is NULL.
 * \param default_location the default folder or file to start the dialog at,
 *                         may be NULL. Not all platforms support this option.
 * \param allow_many if non-zero, the user will be allowed to select multiple
 *                   entries. Not all platforms support this option.
 *
 * \threadsafety This function should be called only from the main thread. The
 *               callback may be invoked from the same thread or from a
 *               different one, depending on the OS's constraints.
 *
 * \since This function is available since SDL 3.1.3.
 *
 * \sa SDL_DialogFileCallback
 * \sa SDL_DialogFileFilter
 * \sa SDL_ShowSaveFileDialog
 * \sa SDL_ShowOpenFolderDialog
 * \sa SDL_ShowFileDialogWithProperties
 */
extern SDL_DECLSPEC void SDLCALL SDL_ShowOpenFileDialog(SDL_DialogFileCallback callback, void *userdata, SDL_Window *window, const SDL_DialogFileFilter *filters, int nfilters, const char *default_location, bool allow_many);

/**
 * Displays a dialog that lets the user choose a new or existing file on their
 * filesystem.
 *
 * This is an asynchronous function; it will return immediately, and the
 * result will be passed to the callback.
 *
 * The callback will be invoked with a null-terminated list of files the user
 * chose. The list will be empty if the user canceled the dialog, and it will
 * be NULL if an error occurred.
 *
 * Note that the callback may be called from a different thread than the one
 * the function was invoked on.
 *
 * The chosen file may or may not already exist.
 *
 * On Linux, dialogs may require XDG Portals, which requires DBus, which
 * requires an event-handling loop. Apps that do not use SDL to handle events
 * should add a call to SDL_PumpEvents in their main loop.
 *
 * \param callback a function pointer to be invoked when the user selects a
 *                 file and accepts, or cancels the dialog, or an error
 *                 occurs.
 * \param userdata an optional pointer to pass extra data to the callback when
 *                 it will be invoked.
 * \param window the window that the dialog should be modal for, may be NULL.
 *               Not all platforms support this option.
 * \param filters a list of filters, may be NULL. Not all platforms support
 *                this option, and platforms that do support it may allow the
 *                user to ignore the filters. If non-NULL, it must remain
 *                valid at least until the callback is invoked.
 * \param nfilters the number of filters. Ignored if filters is NULL.
 * \param default_location the default folder or file to start the dialog at,
 *                         may be NULL. Not all platforms support this option.
 *
 * \threadsafety This function should be called only from the main thread. The
 *               callback may be invoked from the same thread or from a
 *               different one, depending on the OS's constraints.
 *
 * \since This function is available since SDL 3.1.3.
 *
 * \sa SDL_DialogFileCallback
 * \sa SDL_DialogFileFilter
 * \sa SDL_ShowOpenFileDialog
 * \sa SDL_ShowOpenFolderDialog
 * \sa SDL_ShowFileDialogWithProperties
 */
extern SDL_DECLSPEC void SDLCALL SDL_ShowSaveFileDialog(SDL_DialogFileCallback callback, void *userdata, SDL_Window *window, const SDL_DialogFileFilter *filters, int nfilters, const char *default_location);

/**
 * Displays a dialog that lets the user select a folder on their filesystem.
 *
 * This is an asynchronous function; it will return immediately, and the
 * result will be passed to the callback.
 *
 * The callback will be invoked with a null-terminated list of files the user
 * chose. The list will be empty if the user canceled the dialog, and it will
 * be NULL if an error occurred.
 *
 * Note that the callback may be called from a different thread than the one
 * the function was invoked on.
 *
 * Depending on the platform, the user may be allowed to input paths that
 * don't yet exist.
 *
 * On Linux, dialogs may require XDG Portals, which requires DBus, which
 * requires an event-handling loop. Apps that do not use SDL to handle events
 * should add a call to SDL_PumpEvents in their main loop.
 *
 * \param callback a function pointer to be invoked when the user selects a
 *                 file and accepts, or cancels the dialog, or an error
 *                 occurs.
 * \param userdata an optional pointer to pass extra data to the callback when
 *                 it will be invoked.
 * \param window the window that the dialog should be modal for, may be NULL.
 *               Not all platforms support this option.
 * \param default_location the default folder or file to start the dialog at,
 *                         may be NULL. Not all platforms support this option.
 * \param allow_many if non-zero, the user will be allowed to select multiple
 *                   entries. Not all platforms support this option.
 *
 * \threadsafety This function should be called only from the main thread. The
 *               callback may be invoked from the same thread or from a
 *               different one, depending on the OS's constraints.
 *
 * \since This function is available since SDL 3.1.3.
 *
 * \sa SDL_DialogFileCallback
 * \sa SDL_ShowOpenFileDialog
 * \sa SDL_ShowSaveFileDialog
 * \sa SDL_ShowFileDialogWithProperties
 */
extern SDL_DECLSPEC void SDLCALL SDL_ShowOpenFolderDialog(SDL_DialogFileCallback callback, void *userdata, SDL_Window *window, const char *default_location, bool allow_many);

/**
 * Various types of file dialogs.
 *
 * This is used by SDL_ShowFileDialogWithProperties() to decide what kind of
 * dialog to present to the user.
 *
 * \since This enum is available since SDL 3.1.3.
 *
 * \sa SDL_ShowFileDialogWithProperties
 */
typedef enum SDL_FileDialogType
{
    SDL_FILEDIALOG_OPENFILE,
    SDL_FILEDIALOG_SAVEFILE,
    SDL_FILEDIALOG_OPENFOLDER
} SDL_FileDialogType;

/**
 * Create and launch a file dialog with the specified properties.
 *
 * These are the supported properties:
 *
 * - `SDL_PROP_FILE_DIALOG_FILTERS_POINTER`: a pointer to a list of
 *   SDL_DialogFileFilter structs, which will be used as filters for
 *   file-based selections. Ignored if the dialog is an "Open Folder" dialog.
 *   If non-NULL, the array of filters must remain valid at least until the
 *   callback is invoked.
 * - `SDL_PROP_FILE_DIALOG_NFILTERS_NUMBER`: the number of filters in the
 *   array of filters, if it exists.
 * - `SDL_PROP_FILE_DIALOG_WINDOW_POINTER`: the window that the dialog should
 *   be modal for.
 * - `SDL_PROP_FILE_DIALOG_LOCATION_STRING`: the default folder or file to
 *   start the dialog at.
 * - `SDL_PROP_FILE_DIALOG_MANY_BOOLEAN`: true to allow the user to select
 *   more than one entry.
 * - `SDL_PROP_FILE_DIALOG_TITLE_STRING`: the title for the dialog.
 * - `SDL_PROP_FILE_DIALOG_ACCEPT_STRING`: the label that the accept button
 *   should have.
 * - `SDL_PROP_FILE_DIALOG_CANCEL_STRING`: the label that the cancel button
 *   should have.
 *
 * Note that each platform may or may not support any of the properties.
 *
 * \param type the type of file dialog.
 * \param callback a function pointer to be invoked when the user selects a
 *                 file and accepts, or cancels the dialog, or an error
 *                 occurs.
 * \param userdata an optional pointer to pass extra data to the callback when
 *                 it will be invoked.
 * \param props the properties to use.
 *
 * \threadsafety This function should be called only from the main thread. The
 *               callback may be invoked from the same thread or from a
 *               different one, depending on the OS's constraints.
 *
 * \since This function is available since SDL 3.2.0.
 *
 * \sa SDL_FileDialogType
 * \sa SDL_DialogFileCallback
 * \sa SDL_DialogFileFilter
 * \sa SDL_ShowOpenFileDialog
 * \sa SDL_ShowSaveFileDialog
 * \sa SDL_ShowOpenFolderDialog
 */
extern SDL_DECLSPEC void SDLCALL SDL_ShowFileDialogWithProperties(SDL_FileDialogType type, SDL_DialogFileCallback callback, void *userdata, SDL_PropertiesID props);

#define SDL_PROP_FILE_DIALOG_FILTERS_POINTER     "SDL.filedialog.filters"
#define SDL_PROP_FILE_DIALOG_NFILTERS_NUMBER     "SDL.filedialog.nfilters"
#define SDL_PROP_FILE_DIALOG_WINDOW_POINTER      "SDL.filedialog.window"
#define SDL_PROP_FILE_DIALOG_LOCATION_STRING     "SDL.filedialog.location"
#define SDL_PROP_FILE_DIALOG_MANY_BOOLEAN        "SDL.filedialog.many"
#define SDL_PROP_FILE_DIALOG_TITLE_STRING        "SDL.filedialog.title"
#define SDL_PROP_FILE_DIALOG_ACCEPT_STRING       "SDL.filedialog.accept"
#define SDL_PROP_FILE_DIALOG_CANCEL_STRING       "SDL.filedialog.cancel"

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include <SDL3/SDL_close_code.h>

#endif /* SDL_dialog_h_ */