locale: Implemented SDL_GetPreferredLocales().

This was something I proposed a long time ago, Sylvain Becker did additional work on it, then back to me. Fixes Bugzilla #2131.
2025-12-12 14:46:19 +00:00 · 2020-05-04 02:27:29 -04:00
parent 1e5dd06f83
commit fa23e3d00b
42 changed files with 1318 additions and 4 deletions
--- a/src/locale/unix/SDL_syslocale.c
+++ b/src/locale/unix/SDL_syslocale.c
@@ -0,0 +1,110 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2020 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.
+*/
+
+#include "../../SDL_internal.h"
+#include "../SDL_syslocale.h"
+#include "SDL_assert.h"
+
+static void
+normalize_locale_str(char *dst, char *str, size_t buflen)
+{
+    char *ptr;
+
+    ptr = SDL_strchr(str, '.');  /* chop off encoding if specified. */
+    if (ptr != NULL) {
+        *ptr = '\0';
+    }
+
+    ptr = SDL_strchr(str, '@');  /* chop off extra bits if specified. */
+    if (ptr != NULL) {
+        *ptr = '\0';
+    }
+
+    /* The "C" locale isn't useful for our needs, ignore it if you see it. */
+    if ((str[0] == 'C') && (str[1] == '\0')) {
+        return;
+    }
+
+    if (*str) {
+        if (*dst) {
+            SDL_strlcat(dst, ",", buflen);  /* SDL has these split by commas */
+        }
+        SDL_strlcat(dst, str, buflen);
+    }
+}
+
+static void
+normalize_locales(char *dst, char *src, size_t buflen)
+{
+    char *ptr;
+
+    /* entries are separated by colons */
+    while ((ptr = SDL_strchr(src, ':')) != NULL) {
+        *ptr = '\0';
+        normalize_locale_str(dst, src, buflen);
+        src = ptr + 1;
+    }
+    normalize_locale_str(dst, src, buflen);
+}
+
+void
+SDL_SYS_GetPreferredLocales(char *buf, size_t buflen)
+{
+    /* !!! FIXME: should we be using setlocale()? Or some D-Bus thing? */
+    SDL_bool isstack;
+    const char *envr;
+    char *tmp;
+
+    SDL_assert(buflen > 0);
+    tmp = SDL_small_alloc(char, buflen, &isstack);
+    if (!tmp) {
+        SDL_OutOfMemory();
+        return;
+    }
+
+    *tmp = '\0';
+
+    /* LANG is the primary locale (maybe) */
+    envr = SDL_getenv("LANG");
+    if (envr) {
+        SDL_strlcpy(tmp, envr, buflen);
+    }
+
+    /* fallback languages */
+    envr = SDL_getenv("LANGUAGE");
+    if (envr) {
+        if (*tmp) {
+            SDL_strlcat(tmp, ":", buflen);
+        }
+        SDL_strlcat(tmp, envr, buflen);
+    }
+
+    if (*tmp == '\0') {
+        SDL_SetError("LANG environment variable isn't set");
+    } else {
+        normalize_locales(buf, tmp, buflen);
+    }
+
+    SDL_small_free(tmp, isstack);
+}
+
+/* vi: set ts=4 sw=4 expandtab: */
+