Convert immodules to use an extension point

Add an extension point called gtk-im-module, which requires
the type GtkIMContext. Simplify the loading by using GIO
infrastructure. Drop the locale filtering for now, I don't
think it is really necessary nowadays.

Convert existing platform modules to gio modules.
Sill to do: Drop the conditional build machinery.
Either always include them, or never.

1 files changed, 92 insertions, 759 deletions

diff --git a/gtk/gtkimmodule.c b/gtk/gtkimmodule.c
index 5d517f7a7f..021b5c10b5 100644
--- a/gtk/gtkimmodule.c
+++ b/gtk/gtkimmodule.c
@@ -31,6 +31,7 @@
 
 #include <glib/gstdio.h>
 #include <gmodule.h>
+#include "gtkimmodule.h"
 #include "gtkimmoduleprivate.h"
 #include "gtkimcontextsimple.h"
 #include "gtkmodulesprivate.h"
@@ -59,595 +60,10 @@
 #include <windows.h>
 #endif
 
-#undef GDK_DEPRECATED
-#undef GDK_DEPRECATED_FOR
-#define GDK_DEPRECATED
-#define GDK_DEPRECATED_FOR(f)
-
-/* We need to call getc() a lot in a loop. This is suboptimal,
- * as getc() does thread locking on the FILE it is given.
- * To optimize that, lock the file first, then call getc(),
- * then unlock.
- * If locking functions are not present in libc, fall back
- * to the suboptimal getc().
- */
-#if !defined(HAVE_FLOCKFILE) && !defined(HAVE__LOCK_FILE)
-#  define flockfile(f) (void)1
-#  define funlockfile(f) (void)1
-#  define getc_unlocked(f) getc(f)
-#elif !defined(HAVE_FLOCKFILE) && defined(HAVE__LOCK_FILE)
-#  define flockfile(f) _lock_file(f)
-#  define funlockfile(f) _unlock_file(f)
-#  define getc_unlocked(f) _getc_nolock(f)
-#endif
-
 #define SIMPLE_ID "gtk-im-context-simple"
 #define NONE_ID   "gtk-im-context-none"
 
 /**
- * GtkIMContextInfo:
- * @context_id: The unique identification string of the input method.
- * @context_name: The human-readable name of the input method.
- * @domain: Translation domain to be used with dgettext()
- * @domain_dirname: Name of locale directory for use with bindtextdomain()
- * @default_locales: A colon-separated list of locales where this input method
- *   should be the default. The asterisk “*” sets the default for all locales.
- *
- * Bookkeeping information about a loadable input method.
- */
-
-typedef struct _GtkIMModule      GtkIMModule;
-typedef struct _GtkIMModuleClass GtkIMModuleClass;
-
-#define GTK_TYPE_IM_MODULE          (gtk_im_module_get_type ())
-#define GTK_IM_MODULE(im_module)    (G_TYPE_CHECK_INSTANCE_CAST ((im_module), GTK_TYPE_IM_MODULE, GtkIMModule))
-#define GTK_IS_IM_MODULE(im_module) (G_TYPE_CHECK_INSTANCE_TYPE ((im_module), GTK_TYPE_IM_MODULE))
-
-struct _GtkIMModule
-{
-  GTypeModule parent_instance;
-  
-  gboolean builtin;
-
-  GModule *library;
-
-  void          (*list)   (const GtkIMContextInfo ***contexts,
- 		           guint                    *n_contexts);
-  void          (*init)   (GTypeModule              *module);
-  void          (*exit)   (void);
-  GtkIMContext *(*create) (const gchar              *context_id);
-
-  GtkIMContextInfo **contexts;
-  guint n_contexts;
-
-  gchar *path;
-};
-
-struct _GtkIMModuleClass 
-{
-  GTypeModuleClass parent_class;
-};
-
-static GType gtk_im_module_get_type (void);
-
-static gint n_loaded_contexts = 0;
-static GHashTable *contexts_hash = NULL;
-static GSList *modules_list = NULL;
-
-static gboolean
-gtk_im_module_load (GTypeModule *module)
-{
-  GtkIMModule *im_module = GTK_IM_MODULE (module);
-  
-  if (!im_module->builtin)
-    {
-      im_module->library = g_module_open (im_module->path, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
-      if (!im_module->library)
-	{
-	  g_warning ("%s", g_module_error());
-	  return FALSE;
-	}
-  
-      /* extract symbols from the lib */
-      if (!g_module_symbol (im_module->library, "im_module_init",
-			    (gpointer *)&im_module->init) ||
-	  !g_module_symbol (im_module->library, "im_module_exit", 
-			    (gpointer *)&im_module->exit) ||
-	  !g_module_symbol (im_module->library, "im_module_list", 
-			    (gpointer *)&im_module->list) ||
-	  !g_module_symbol (im_module->library, "im_module_create", 
-			    (gpointer *)&im_module->create))
-	{
-	  g_warning ("%s", g_module_error());
-	  g_module_close (im_module->library);
-	  
-	  return FALSE;
-	}
-    }
-	    
-  /* call the module's init function to let it */
-  /* setup anything it needs to set up. */
-  im_module->init (module);
-
-  return TRUE;
-}
-
-static void
-gtk_im_module_unload (GTypeModule *module)
-{
-  GtkIMModule *im_module = GTK_IM_MODULE (module);
-  
-  im_module->exit();
-
-  if (!im_module->builtin)
-    {
-      g_module_close (im_module->library);
-      im_module->library = NULL;
-
-      im_module->init = NULL;
-      im_module->exit = NULL;
-      im_module->list = NULL;
-      im_module->create = NULL;
-    }
-}
-
-G_DEFINE_TYPE (GtkIMModule, gtk_im_module, G_TYPE_TYPE_MODULE)
-
-/* This only will ever be called if an error occurs during
- * initialization
- */
-static void
-gtk_im_module_finalize (GObject *object)
-{
-  GtkIMModule *module = GTK_IM_MODULE (object);
-
-  g_free (module->path);
-
-  G_OBJECT_CLASS (gtk_im_module_parent_class)->finalize (object);
-}
-
-static void
-gtk_im_module_class_init (GtkIMModuleClass *class)
-{
-  GTypeModuleClass *module_class = G_TYPE_MODULE_CLASS (class);
-  GObjectClass *gobject_class = G_OBJECT_CLASS (class);
-
-  module_class->load = gtk_im_module_load;
-  module_class->unload = gtk_im_module_unload;
-
-  gobject_class->finalize = gtk_im_module_finalize;
-}
-
-static void 
-gtk_im_module_init (GtkIMModule* object)
-{
-}
-
-static void
-free_info (GtkIMContextInfo *info)
-{
-  g_free ((char *)info->context_id);
-  g_free ((char *)info->context_name);
-  g_free ((char *)info->domain);
-  g_free ((char *)info->domain_dirname);
-  g_free ((char *)info->default_locales);
-  g_free (info);
-}
-
-static void
-add_module (GtkIMModule *module, GSList *infos)
-{
-  GSList *tmp_list = infos;
-  gint i = 0;
-  gint n = g_slist_length (infos);
-  module->contexts = g_new (GtkIMContextInfo *, n);
-
-  while (tmp_list)
-    {
-      GtkIMContextInfo *info = tmp_list->data;
-  
-      if (g_hash_table_lookup (contexts_hash, info->context_id))
-	{
-	  free_info (info);	/* Duplicate */
-	}
-      else
-	{
-	  g_hash_table_insert (contexts_hash, (char *)info->context_id, module);
-	  module->contexts[i++] = tmp_list->data;
-	  n_loaded_contexts++;
-	}
-      
-      tmp_list = tmp_list->next;
-    }
-  g_slist_free (infos);
-  module->n_contexts = i;
-
-  modules_list = g_slist_prepend (modules_list, module);
-}
-
-#ifdef G_OS_WIN32
-
-static void
-correct_libdir_prefix (gchar **path)
-{
-  /* GTK_LIBDIR is the build-time libdir */
-  if (strncmp (*path, GTK_LIBDIR, strlen (GTK_LIBDIR)) == 0)
-    {
-      /* This is an entry put there by make install on the
-       * packager's system. On Windows a prebuilt GTK+
-       * package can be installed in a random
-       * location. The gtk.immodules file distributed in
-       * such a package contains paths from the package
-       * builder's machine. Replace the path with the real
-       * one on this machine.
-       */
-      gchar *tem = *path;
-      *path = g_strconcat (_gtk_get_libdir (), tem + strlen (GTK_LIBDIR), NULL);
-      g_free (tem);
-    }
-}
-
-static void
-correct_localedir_prefix (gchar **path)
-{
-  /* See above */
-  if (strncmp (*path, GTK_LOCALEDIR, strlen (GTK_LOCALEDIR)) == 0)
-    {
-      gchar *tem = *path;
-      *path = g_strconcat (_gtk_get_localedir (), tem + strlen (GTK_LOCALEDIR), NULL);
-      g_free (tem);
-    }
-}
-#endif
-
-
-G_GNUC_UNUSED static GtkIMModule *
-add_builtin_module (const gchar             *module_name,
-		    const GtkIMContextInfo **contexts,
-		    int                      n_contexts)
-{
-  GtkIMModule *module = g_object_new (GTK_TYPE_IM_MODULE, NULL);
-  GSList *infos = NULL;
-  int i;
-
-  for (i = 0; i < n_contexts; i++)
-    {
-      GtkIMContextInfo *info = g_new (GtkIMContextInfo, 1);
-      info->context_id = g_strdup (contexts[i]->context_id);
-      info->context_name = g_strdup (contexts[i]->context_name);
-      info->domain = g_strdup (contexts[i]->domain);
-      info->domain_dirname = g_strdup (contexts[i]->domain_dirname);
-#ifdef G_OS_WIN32
-      correct_localedir_prefix ((char **) &info->domain_dirname);
-#endif
-      info->default_locales = g_strdup (contexts[i]->default_locales);
-      infos = g_slist_prepend (infos, info);
-    }
-
-  module->builtin = TRUE;
-  g_type_module_set_name (G_TYPE_MODULE (module), module_name);
-  add_module (module, infos);
-
-  return module;
-}
-
-/*
- * gtk_get_im_module_path:
- *
- * Obtains the path in which to look for IM modules. See the documentation
- * of the `GTK_PATH`
- * environment variable for more details about looking up modules. This
- * function is useful solely for utilities supplied with GTK+ and should
- * not be used by applications under normal circumstances.
- *
- * Returns: (type filename): a newly-allocated string containing the
- *    path in which to look for IM modules.
- */
-gchar *
-gtk_get_im_module_path (void)
-{
-  gchar **paths = _gtk_get_module_path ("immodules");
-  gchar *result = g_strjoinv (G_SEARCHPATH_SEPARATOR_S, paths);
-  g_strfreev (paths);
-
-  return result;
-}
-
-/*
- * gtk_get_im_module_file:
- *
- * Obtains the path to the IM modules file. See the documentation
- * of the `GTK_IM_MODULE_FILE`
- * environment variable for more details.
- *
- * Returns: (type filename): a newly-allocated string containing the
- *    name of the file listing the IM modules available for loading
- */
-gchar *
-gtk_get_im_module_file (void)
-{
-  const gchar *var = g_getenv ("GTK_IM_MODULE_FILE");
-  gchar *result = NULL;
-
-  if (var)
-    result = g_strdup (var);
-
-  if (!result)
-    {
-      gchar *path;
-
-      var = g_getenv ("GTK_EXE_PREFIX");
-
-      if (var)
-        path = g_build_filename (var, "lib", "gtk-4.0", GTK_BINARY_VERSION, "immodules.cache", NULL);
-      else
-        path = g_build_filename (_gtk_get_libdir (), "gtk-4.0", GTK_BINARY_VERSION, "immodules.cache", NULL);
-
-      return path;
-    }
-
-  return result;
-}
-
-static void
-gtk_im_module_initialize (void)
-{
-  GString *line_buf = g_string_new (NULL);
-  GString *tmp_buf = g_string_new (NULL);
-  gchar *filename = gtk_get_im_module_file();
-  FILE *file;
-  gboolean have_error = FALSE;
-
-  GtkIMModule *module = NULL;
-  GSList *infos = NULL;
-
-  contexts_hash = g_hash_table_new (g_str_hash, g_str_equal);
-
-#define do_builtin(m)							\
-  {									\
-    const GtkIMContextInfo **contexts;					\
-    int n_contexts;							\
-    extern void _gtk_immodule_ ## m ## _list (const GtkIMContextInfo ***contexts, \
-					      int                      *n_contexts); \
-    extern void _gtk_immodule_ ## m ## _init (GTypeModule *module);	\
-    extern void _gtk_immodule_ ## m ## _exit (void);			\
-    extern GtkIMContext *_gtk_immodule_ ## m ## _create (const gchar *context_id); \
-									\
-    _gtk_immodule_ ## m ## _list (&contexts, &n_contexts);		\
-    module = add_builtin_module (#m, contexts, n_contexts);		\
-    module->init = _gtk_immodule_ ## m ## _init;			\
-    module->exit = _gtk_immodule_ ## m ## _exit;			\
-    module->create = _gtk_immodule_ ## m ## _create;			\
-    module = NULL;							\
-  }
-
-#ifdef INCLUDE_IM_ime
-  do_builtin (ime);
-#endif
-#ifdef INCLUDE_IM_xim
-  do_builtin (xim);
-#endif
-#ifdef INCLUDE_IM_broadway
-  do_builtin (broadway);
-#endif
-#ifdef INCLUDE_IM_wayland
-  do_builtin (wayland);
-#endif
-
-#undef do_builtin
-
-  file = g_fopen (filename, "r");
-  if (!file)
-    {
-      /* In case someone wants only the default input method,
-       * we allow no file at all.
-       */
-      g_string_free (line_buf, TRUE);
-      g_string_free (tmp_buf, TRUE);
-      g_free (filename);
-      return;
-    }
-
-  while (!have_error && gtk_read_line (file, line_buf))
-    {
-      const char *p;
-
-      p = line_buf->str;
-
-      if (!gtk_skip_space (&p))
-	{
-	  /* Blank line marking the end of a module
-	   */
-	  if (module && *p != '#')
-	    {
-	      add_module (module, infos);
-	      module = NULL;
-	      infos = NULL;
-	    }
-
-	  continue;
-	}
-
-      if (!module)
-	{
-	  /* Read a module location
-	   */
-	  module = g_object_new (GTK_TYPE_IM_MODULE, NULL);
-
-	  if (!gtk_scan_string (&p, tmp_buf) || gtk_skip_space (&p))
-	    {
-	      g_warning ("Error parsing context info in '%s'\n  %s", filename, line_buf->str);
-	      have_error = TRUE;
-	    }
-
-	  module->path = g_strdup (tmp_buf->str);
-#ifdef G_OS_WIN32
-	  correct_libdir_prefix (&module->path);
-#endif
-	  g_type_module_set_name (G_TYPE_MODULE (module), module->path);
-	}
-      else
-	{
-	  GtkIMContextInfo *info = g_new0 (GtkIMContextInfo, 1);
-
-	  /* Read information about a context type
-	   */
-	  if (!gtk_scan_string (&p, tmp_buf))
-	    goto context_error;
-	  info->context_id = g_strdup (tmp_buf->str);
-
-	  if (!gtk_scan_string (&p, tmp_buf))
-	    goto context_error;
-	  info->context_name = g_strdup (tmp_buf->str);
-
-	  if (!gtk_scan_string (&p, tmp_buf))
-	    goto context_error;
-	  info->domain = g_strdup (tmp_buf->str);
-
-	  if (!gtk_scan_string (&p, tmp_buf))
-	    goto context_error;
-
-	  info->domain_dirname = g_strdup (tmp_buf->str);
-#ifdef G_OS_WIN32
-	  correct_localedir_prefix ((char **) &info->domain_dirname);
-#endif
-
-	  if (!gtk_scan_string (&p, tmp_buf))
-	    goto context_error;
-	  info->default_locales = g_strdup (tmp_buf->str);
-
-	  if (gtk_skip_space (&p))
-	    goto context_error;
-
-	  infos = g_slist_prepend (infos, info);
-	  continue;
-
-	context_error:
-	  g_warning ("Error parsing context info in '%s'\n  %s", filename, line_buf->str);
-	  have_error = TRUE;
-	}
-    }
-
-  if (have_error)
-    {
-      g_slist_free_full (infos, (GDestroyNotify)free_info);
-      g_object_unref (module);
-    }
-  else if (module)
-    add_module (module, infos);
-
-  fclose (file);
-  g_string_free (line_buf, TRUE);
-  g_string_free (tmp_buf, TRUE);
-  g_free (filename);
-}
-
-static gint
-compare_gtkimcontextinfo_name (const GtkIMContextInfo **a,
-                               const GtkIMContextInfo **b)
-{
-  return g_utf8_collate ((*a)->context_name, (*b)->context_name);
-}
-
-/**
- * _gtk_im_module_list:
- * @contexts: location to store an array of pointers to #GtkIMContextInfo
- *            this array should be freed with g_free() when you are finished.
- *            The structures it points are statically allocated and should
- *            not be modified or freed.
- * @n_contexts: the length of the array stored in @contexts
- *
- * List all available types of input method context
- */
-void
-_gtk_im_module_list (const GtkIMContextInfo ***contexts,
-		     guint                    *n_contexts)
-{
-  int n = 0;
-
-  static
-#ifndef G_OS_WIN32
-	  const
-#endif
-		GtkIMContextInfo simple_context_info = {
-    SIMPLE_ID,
-    NC_("input method menu", "Simple"),
-    GETTEXT_PACKAGE,
-#ifdef GTK_LOCALEDIR
-    GTK_LOCALEDIR,
-#else
-    "",
-#endif
-    ""
-  };
-
-  static
-#ifndef G_OS_WIN32
-	  const
-#endif
-		GtkIMContextInfo none_context_info = {
-    NONE_ID,
-    NC_("input method menu", "None"),
-    GETTEXT_PACKAGE,
-#ifdef GTK_LOCALEDIR
-    GTK_LOCALEDIR,
-#else
-    "",
-#endif
-    ""
-  };
-
-#ifdef G_OS_WIN32
-  static gboolean beenhere = FALSE;
-#endif
-
-  if (!contexts_hash)
-    gtk_im_module_initialize ();
-
-#ifdef G_OS_WIN32
-  if (!beenhere)
-    {
-      beenhere = TRUE;
-      /* correct_localedir_prefix() requires its parameter to be a
-       * malloced string
-       */
-      simple_context_info.domain_dirname = g_strdup (simple_context_info.domain_dirname);
-      correct_localedir_prefix ((char **) &simple_context_info.domain_dirname);
-      none_context_info.domain_dirname = g_strdup (none_context_info.domain_dirname);
-      correct_localedir_prefix ((char **) &none_context_info.domain_dirname);
-    }
-#endif
-
-  if (n_contexts)
-    *n_contexts = n_loaded_contexts + 2;
-
-  if (contexts)
-    {
-      GSList *tmp_list;
-      int i;
-
-      *contexts = g_new (const GtkIMContextInfo *, n_loaded_contexts + 2);
-
-      (*contexts)[n++] = &none_context_info;
-      (*contexts)[n++] = &simple_context_info;
-
-      tmp_list = modules_list;
-      while (tmp_list)
-	{
-	  GtkIMModule *module = tmp_list->data;
-
-	  for (i=0; i<module->n_contexts; i++)
-	    (*contexts)[n++] = module->contexts[i];
-  
-	  tmp_list = tmp_list->next;
-	}
-
-      /* first elements (Simple and None) should always be at top */
-      qsort ((*contexts)+2, n-2, sizeof (GtkIMContextInfo *), (GCompareFunc)compare_gtkimcontextinfo_name);
-    }
-}
-
-/**
  * _gtk_im_module_create:
  * @context_id: the context ID for the context type to create
  * 
@@ -660,85 +76,54 @@ _gtk_im_module_list (const GtkIMContextInfo ***contexts,
 GtkIMContext *
 _gtk_im_module_create (const gchar *context_id)
 {
-  GtkIMModule *im_module;
+  GIOExtensionPoint *ep;
+  GIOExtension *ext;
+  GType type;
   GtkIMContext *context = NULL;
 
   if (strcmp (context_id, NONE_ID) == 0)
     return NULL;
 
-  if (!contexts_hash)
-    gtk_im_module_initialize ();
-
-  if (strcmp (context_id, SIMPLE_ID) != 0)
+  ep = g_io_extension_point_lookup (GTK_IM_MODULE_EXTENSION_POINT_NAME);
+  ext = g_io_extension_point_get_extension_by_name (ep, context_id);
+  if (ext)
     {
-      im_module = g_hash_table_lookup (contexts_hash, context_id);
-      if (!im_module)
-	{
-	  g_warning ("Attempt to load unknown IM context type '%s'", context_id);
-	}
-      else
-	{
-	  if (g_type_module_use (G_TYPE_MODULE (im_module)))
-	    {
-	      context = im_module->create (context_id);
-	      g_type_module_unuse (G_TYPE_MODULE (im_module));
-	    }
-
-	  if (!context)
-	    g_warning ("Loading IM context type '%s' failed", context_id);
-	}
+      type = g_io_extension_get_type (ext);
+      context = g_object_new (type, NULL);
     }
 
-  if (!context)
-     return gtk_im_context_simple_new ();
-  else
-    return context;
+  return context;
 }
 
-/* Match @locale against @against.
- * 
- * 'en_US' against “en_US”       => 4
- * 'en_US' against “en”          => 3
- * 'en', “en_UK” against “en_US” => 2
- *  all locales, against “*” 	 => 1
- */
-static gint
-match_locale (const gchar *locale,
-	      const gchar *against,
-	      gint         against_len)
+static gboolean
+is_platform (const char *context_id)
 {
-  if (strcmp (against, "*") == 0)
-    return 1;
-
-  if (g_ascii_strcasecmp (locale, against) == 0)
-    return 4;
-
-  if (g_ascii_strncasecmp (locale, against, 2) == 0)
-    return (against_len == 2) ? 3 : 2;
-
-  return 0;
+  return g_strcmp0 (context_id, "wayland") == 0 ||
+         g_strcmp0 (context_id, "broadway") == 0 ||
+         g_strcmp0 (context_id, "xim") == 0 ||
+         g_strcmp0 (context_id, "ime") == 0;
 }
 
 static gboolean
-match_backend (GtkIMContextInfo *context)
+match_backend (const char *context_id)
 {
 #ifdef GDK_WINDOWING_WAYLAND
-  if (g_strcmp0 (context->context_id, "wayland") == 0)
+  if (g_strcmp0 (context_id, "wayland") == 0)
     return GDK_IS_WAYLAND_DISPLAY (gdk_display_get_default ());
 #endif
 
 #ifdef GDK_WINDOWING_BROADWAY
-  if (g_strcmp0 (context->context_id, "broadway") == 0)
+  if (g_strcmp0 (context_id, "broadway") == 0)
     return GDK_IS_BROADWAY_DISPLAY (gdk_display_get_default ());
 #endif
 
 #ifdef GDK_WINDOWING_X11
-  if (g_strcmp0 (context->context_id, "xim") == 0)
+  if (g_strcmp0 (context_id, "xim") == 0)
     return GDK_IS_X11_DISPLAY (gdk_display_get_default ());
 #endif
 
 #ifdef GDK_WINDOWING_WIN32
-  if (g_strcmp0 (context->context_id, "ime") == 0)
+  if (g_strcmp0 (context_id, "ime") == 0)
     return GDK_IS_WIN32_DISPLAY (gdk_display_get_default ());
 #endif
 
@@ -755,81 +140,21 @@ lookup_immodule (gchar **immodules_list)
       else if (g_strcmp0 (*immodules_list, NONE_ID) == 0)
         return NONE_ID;
       else
-	{
-	  gboolean found;
-	  gchar *context_id;
-	  found = g_hash_table_lookup_extended (contexts_hash, *immodules_list,
-						(gpointer *) &context_id, NULL);
-	  if (found)
-	    return context_id;
-	}
+        {
+          GIOExtensionPoint *ep;
+          GIOExtension *ext;
+
+          ep = g_io_extension_point_lookup (GTK_IM_MODULE_EXTENSION_POINT_NAME);
+          ext = g_io_extension_point_get_extension_by_name (ep, *immodules_list);
+          if (ext)
+            return g_io_extension_get_name (ext);
+        }
       immodules_list++;
     }
 
   return NULL;
 }
 
-#ifdef G_OS_WIN32
-
-/* max size for LOCALE_SISO639LANGNAME and LOCALE_SISO3166CTRYNAME is 9 */
-#define MAX_NAME_SIZE 9
-
-static gchar *
-get_current_input_language (void)
-{
-  LCID lcid;
-  LANGID langid;
-  HKL kblayout;
-  int name_size;
-  wchar_t name[MAX_NAME_SIZE];
-  gchar *language;
-  gchar *country;
-  gchar *full;
-
-  /* Current thread's keyboard layout */
-  kblayout = GetKeyboardLayout(0);
-  /* lowest word in the HKL is the LANGID */
-  langid = LOWORD (kblayout);
-  /* LCID is the LANGID without order */
-  lcid = langid;
-
-  /* Get Language ID */
-  name_size = GetLocaleInfoW (lcid, LOCALE_SISO639LANGNAME, NULL, 0);
-  if (name_size <= 1)
-    return NULL;
-
-  g_assert (name_size <= MAX_NAME_SIZE);
-  GetLocaleInfoW (lcid, LOCALE_SISO639LANGNAME, name, name_size);
-
-  language = g_utf16_to_utf8 (name, name_size, NULL, NULL, NULL);
-  if (!language)
-    return NULL;
-
-  if (SUBLANGID (langid) == SUBLANG_NEUTRAL)
-    return language;
-
-  /* Get Country ID */
-  name_size = GetLocaleInfoW (lcid, LOCALE_SISO3166CTRYNAME, NULL, 0);
-  if (name_size <= 1)
-    return language;
-
-  g_assert (name_size <= MAX_NAME_SIZE);
-  GetLocaleInfoW (lcid, LOCALE_SISO3166CTRYNAME, name, name_size);
-
-  country = g_utf16_to_utf8 (name, name_size, NULL, NULL, NULL);
-  if (!country)
-    return language;
-
-  full = g_strdup_printf ("%s_%s", language, country);
-
-  g_free (language);
-  g_free (country);
-
-  return full;
-}
-
-#endif
-
 /**
  * _gtk_im_module_get_default_context_id:
  * 
@@ -841,26 +166,21 @@ get_current_input_language (void)
 const gchar *
 _gtk_im_module_get_default_context_id (void)
 {
-  GSList *tmp_list;
   const gchar *context_id = NULL;
-  gint best_goodness = 0;
-  gint i;
-  gchar *tmp_locale, *tmp, **immodules;
   const gchar *envvar;
   GtkSettings *settings;
-
-  if (!contexts_hash)
-    gtk_im_module_initialize ();
+  char *tmp;
 
   envvar = g_getenv ("GTK_IM_MODULE");
   if (envvar)
     {
-        immodules = g_strsplit (envvar, ":", 0);
-        context_id = lookup_immodule (immodules);
-        g_strfreev (immodules);
+      char **immodules;
+      immodules = g_strsplit (envvar, ":", 0);
+      context_id = lookup_immodule (immodules);
+      g_strfreev (immodules);
 
-        if (context_id)
-          return context_id;
+      if (context_id)
+        return context_id;
     }
 
   /* Check if the certain immodule is set in XSETTINGS. */
@@ -868,6 +188,8 @@ _gtk_im_module_get_default_context_id (void)
   g_object_get (G_OBJECT (settings), "gtk-im-module", &tmp, NULL);
   if (tmp)
     {
+      char **immodules;
+
       immodules = g_strsplit (tmp, ":", 0);
       context_id = lookup_immodule (immodules);
       g_strfreev (immodules);
@@ -877,57 +199,68 @@ _gtk_im_module_get_default_context_id (void)
         return context_id;
     }
 
-#ifdef G_OS_WIN32
-  /* Read current input locale from the current keyboard info */
-  tmp_locale = get_current_input_language ();
-  if (!tmp_locale)
-    /* Default to system locale when input language is unknown */
-    tmp_locale = _gtk_get_lc_ctype ();
-#else
-  tmp_locale = _gtk_get_lc_ctype ();
-#endif
+  GIOExtensionPoint *ep;
+  GList *list, *l;
 
-  /* Strip the locale code down to the essentials
-   */
-  tmp = strchr (tmp_locale, '.');
-  if (tmp)
-    *tmp = '\0';
-  tmp = strchr (tmp_locale, '@');
-  if (tmp)
-    *tmp = '\0';
-
-  tmp_list = modules_list;
-  while (tmp_list)
+  ep = g_io_extension_point_lookup (GTK_IM_MODULE_EXTENSION_POINT_NAME);
+  list = g_io_extension_point_get_extensions (ep);
+  for (l = list; l; l = l->next)
     {
-      GtkIMModule *module = tmp_list->data;
+      GIOExtension *ext = l->data;
+      const char *context_id;
 
-      for (i = 0; i < module->n_contexts; i++)
-	{
-	  const gchar *p;
+      context_id = g_io_extension_get_name (ext);
+      if (match_backend (context_id))
+        return context_id;
 
-          if (!match_backend (module->contexts[i]))
-            continue;
+      // FIXME: locale matching
+      if (!is_platform (context_id))
+        return context_id;
+    }
+
+  return context_id ? context_id : SIMPLE_ID;
+}
+
+void
+gtk_im_modules_init (void)
+{
+  GIOExtensionPoint *ep;
+  GIOModuleScope *scope;
+  char **paths;
+  int i;
+
+  GTK_NOTE (MODULES,
+            g_print ("Registering extension point %s\n", GTK_IM_MODULE_EXTENSION_POINT_NAME));
 
-          p = module->contexts[i]->default_locales;
-	  while (p)
-	    {
-	      const gchar *q = strchr (p, ':');
-	      gint goodness = match_locale (tmp_locale, p, q ? q - p : strlen (p));
+  ep = g_io_extension_point_register (GTK_IM_MODULE_EXTENSION_POINT_NAME);
+  g_io_extension_point_set_required_type (ep, GTK_TYPE_IM_CONTEXT);
 
-	      if (goodness > best_goodness)
-		{
-		  context_id = module->contexts[i]->context_id;
-		  best_goodness = goodness;
-		}
+  g_type_ensure (gtk_im_context_simple_get_type ());
+  // other builtin im context types go here
 
-	      p = q ? q + 1 : NULL;
-	    }
-	}
+  scope = g_io_module_scope_new (G_IO_MODULE_SCOPE_BLOCK_DUPLICATES);
 
-      tmp_list = tmp_list->next;
+  paths = _gtk_get_module_path ("immodules");
+  for (i = 0; paths[i]; i++)
+    {
+      GTK_NOTE (MODULES,
+                g_print ("Scanning io modules in %s\n", paths[i]));
+      g_io_modules_scan_all_in_directory_with_scope (paths[i], scope);
     }
+  g_strfreev (paths);
 
-  g_free (tmp_locale);
+  g_io_module_scope_free (scope);
 
-  return context_id ? context_id : SIMPLE_ID;
+  {
+    GList *list, *l;
+
+    list = g_io_extension_point_get_extensions (ep);
+    for (l = list; l; l = l->next)
+      {
+        GIOExtension *ext = l->data;
+        g_print ("extension: %s: type %s\n",
+                 g_io_extension_get_name (ext),
+                 g_type_name (g_io_extension_get_type (ext)));
+      }
+  }
 }