SDL_locale.h

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/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2026 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.
*/
 
/**
 * # CategoryLocale
 *
 * SDL locale services.
 *
 * This provides a way to get a list of preferred locales (language plus
 * country) for the user. There is exactly one function:
 * SDL_GetPreferredLocales(), which handles all the heavy lifting, and offers
 * documentation on all the strange ways humans might have configured their
 * language settings.
 */
 
#ifndef SDL_locale_h
#define SDL_locale_h
 
#include <SDL3/SDL_stdinc.h>
#include <SDL3/SDL_error.h>
 
#include <SDL3/SDL_begin_code.h>
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
extern "C" {
/* *INDENT-ON* */
#endif
 
/**
 * A struct to provide locale data.
 *
 * Locale data is split into a spoken language, like English, and an optional
 * country, like Canada.
 *
 * Language strings are ISO-639 language specifiers (such as "en" for English,
 * "de" for German, etc). Country strings are ISO-3166 country codes (such as
 * "US" for the United States, "CA" for Canada, etc). The country might be
 * NULL if there's no specific guidance on them (so you might have `{ "en",
 * "US" }` for American English, but `{ "en", NULL }` means "English language,
 * generically"). Language strings are never NULL.
 *
 * Please note that not all of these strings are 2 characters; some are three
 * or more.
 *
 * \since This struct is available since SDL 3.2.0.
 *
 * \sa SDL_GetPreferredLocales
 */
typedef struct SDL_Locale
{
    const char *language;  /**< A language name, like "en" for English. */
    const char *country;  /**< A country, like "US" for America. Can be NULL. */
} SDL_Locale;
 
/**
 * Report the user's preferred locale.
 *
 * This returns a NULL-terminated array of pointers to locale information. The
 * returned list of locales are in the order of the user's preference. For
 * example, a German citizen that is fluent in US English and knows enough
 * Japanese to navigate around Tokyo might have a list like:
 *
 * ```c
 * {
 *     { "de", "DE" },
 *     { "en", "US" },
 *     { "jp", NULL },
 *     NULL
 * }
 * ```
 *
 * Someone from England might prefer British English (where "color" is spelled
 * "colour", etc), but will settle for anything like it:
 *
 * ```c
 * {
 *     { "en", "GB" },
 *     { "en", NULL },
 *     NULL
 * }
 * ```
 *
 * This function returns NULL on error, including when the platform does not
 * supply this information at all.
 *
 * Note that this information is merely guidance; some platforms don't supply
 * it, some only supply a single language ever, some don't ever provide
 * country information, etc. Be prepared to receive surprising results and
 * plan to have fallbacks.
 *
 * This might be a "slow" call that has to query the operating system. It's
 * best to ask for this once and save the results. However, this list can
 * change, usually because the user has changed a system preference outside of
 * your program; SDL will send an SDL_EVENT_LOCALE_CHANGED event in this case,
 * if possible, and you can call this function again to get an updated copy of
 * preferred locales.
 *
 * The returned pointer is a single allocation (all the strings and structures
 * are allocated in a single chunk, even though they look like separate data),
 * and should be disposed of with a single call to SDL_free() when it is no
 * longer needed.
 *
 * If not NULL, `*count` will be set to number of items returned, not counting
 * the terminating NULL pointer. `count` may be NULL if one plans to simply
 * iterate the returned array directly.
 *
 * \param count a pointer filled in with the number of locales returned, may
 *              be NULL.
 * \returns a NULL-terminated array of locale pointers, or NULL on failure;
 *          call SDL_GetError() for more information. Call SDL_free() when
 *          done with this pointer.
 *
 * \threadsafety This function is not thread safe.
 *
 * \since This function is available since SDL 3.2.0.
 */
extern SDL_DECLSPEC SDL_Locale ** SDLCALL SDL_GetPreferredLocales(int *count);
 
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
}
/* *INDENT-ON* */
#endif
#include <SDL3/SDL_close_code.h>
 
#endif /* SDL_locale_h */