[gtk/wip/fanc999/fontchooser.win32.gtk3: 3/3] gtk: Add Windows implementation of language-names.c

[Chun-wei Fan <fanchunwei src gnome org>]

commit 87cd93679429c52b4366063486165a2167e101dc
Author: Chun-wei Fan <fanc999 yahoo com tw>
Date:   Tue Dec 25 21:13:07 2018 +0800

    gtk: Add Windows implementation of language-names.c
    
    This enables us to acquire the translated (localized) language name info
    on Windows using the Windows APIs, which removes the need of the iso-codes
    package, which can be cumbersome to install and use on Windows with the
    translations built.
    
    This is intended for both the PangoFT implementation of the font
    features, as well as for the upcoming PangoWin32 implementation of the
    font features, which currently needs to be going through FreeType.

 gtk/language-names-win32.c | 100 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
---
diff --git a/gtk/language-names-win32.c b/gtk/language-names-win32.c
new file mode 100644
index 0000000000..60ea2c1ed8
--- /dev/null
+++ b/gtk/language-names-win32.c
@@ -0,0 +1,100 @@
+#include "config.h"
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <glib.h>
+#include <pango/pango.h>
+
+#ifdef HAVE_HARFBUZZ
+#include <hb-ot.h>
+
+/* if we are using native Windows (PangoWin32), use DirectWrite */
+static BOOL CALLBACK
+get_win32_all_locales_scripts (LPWSTR locale_w, DWORD flags, LPARAM param)
+{
+  wchar_t *langname_w = NULL;
+  wchar_t *locale_abbrev_w = NULL;
+  gchar *langname, *locale_abbrev, *locale, *p;
+  gint i;
+  hb_language_t lang;
+  GHashTable *ht_scripts_langs = (GHashTable *)param;
+
+  gint langname_size, locale_abbrev_size;
+  langname_size = GetLocaleInfoEx (locale_w, LOCALE_SLOCALIZEDDISPLAYNAME, langname_w, 0);
+  if (langname_size == 0)
+    return FALSE;
+
+  langname_w = g_new0 (wchar_t, langname_size);
+
+  if (langname_size == 0)
+    return FALSE;
+
+  GetLocaleInfoEx (locale_w, LOCALE_SLOCALIZEDDISPLAYNAME, langname_w, langname_size);
+  langname = g_utf16_to_utf8 (langname_w, -1, NULL, NULL, NULL);
+  locale = g_utf16_to_utf8 (locale_w, -1, NULL, NULL, NULL);
+  p = strchr (locale, '-');
+  lang = hb_language_from_string (locale, p ? p - locale : -1);
+  if (g_hash_table_lookup (ht_scripts_langs, lang) == NULL)
+    g_hash_table_insert (ht_scripts_langs, lang, langname);
+
+  /* track 3-letter ISO639-2/3 language codes as well */
+  locale_abbrev_size = GetLocaleInfoEx (locale_w, LOCALE_SABBREVLANGNAME, locale_abbrev_w, 0);
+  if (locale_abbrev_size > 0)
+    {
+      locale_abbrev_w = g_new0 (wchar_t, locale_abbrev_size);
+      GetLocaleInfoEx (locale_w, LOCALE_SABBREVLANGNAME, locale_abbrev_w, locale_abbrev_size);
+
+         locale_abbrev = g_utf16_to_utf8 (locale_abbrev_w, -1, NULL, NULL, NULL);
+      lang = hb_language_from_string (locale_abbrev, -1);
+      if (g_hash_table_lookup (ht_scripts_langs, lang) == NULL)
+        g_hash_table_insert (ht_scripts_langs, lang, langname);
+
+      g_free (locale_abbrev);
+      g_free (locale_abbrev_w);
+    }
+
+  g_free (locale);
+  g_free (langname_w);
+
+  return TRUE;
+}
+
+static GHashTable *
+languages_init (void)
+{
+  static GHashTable *ht_langtag_locales = NULL;
+  static volatile gsize inited = 0;
+
+  if (g_once_init_enter (&inited))
+    {
+      gchar *locales, *script;
+      ht_langtag_locales = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, g_free);
+      EnumSystemLocalesEx (&get_win32_all_locales_scripts, LOCALE_ALL, (LPARAM)ht_langtag_locales, NULL);
+      g_once_init_leave (&inited, 1);
+    }
+
+  return ht_langtag_locales;
+}
+
+const char *
+get_language_name (PangoLanguage *language)
+{
+  GHashTable *ht_lang = languages_init ();
+
+  return (const char *) g_hash_table_lookup (ht_lang, language);
+}
+
+const char *
+get_language_name_for_tag (guint32 tag)
+{
+  hb_language_t lang;
+  const char *s;
+
+  lang = hb_ot_tag_to_language (tag);
+  s = hb_language_to_string (lang);
+
+  return get_language_name (pango_language_from_string (s));
+}
+
+#endif
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