gio/gosxcontenttype.m - third_party/glib - Git at Google

 /* GIO - GLib Input, Output and Streaming Library
  *
  * Copyright (C) 2014 Patrick Griffis
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General
  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  *
  */

 #include "config.h"

 #include "gcontenttype.h"
 #include "gicon.h"
 #include "gthemedicon.h"

 #include <CoreServices/CoreServices.h>

 #define XDG_PREFIX _gio_xdg
 #include "xdgmime/xdgmime.h"

 /* We lock this mutex whenever we modify global state in this module.  */
 G_LOCK_DEFINE_STATIC (gio_xdgmime);


 /*< internal >
  * create_cfstring_from_cstr:
  * @cstr: a #gchar
  *
  * Converts a cstr to a utf8 cfstring
  * It must be CFReleased()'d.
  *
  */
 static CFStringRef
 create_cfstring_from_cstr (const gchar *cstr)
 {
   return CFStringCreateWithCString (NULL, cstr, kCFStringEncodingUTF8);
 }

 /*< internal >
  * create_cstr_from_cfstring:
  * @str: a #CFStringRef
  *
  * Converts a cfstring to a utf8 cstring.
  * The incoming cfstring is released for you.
  * The returned string must be g_free()'d.
  *
  */
 static gchar *
 create_cstr_from_cfstring (CFStringRef str)
 {
   CFIndex length;
   CFIndex maxlen;
   gchar *buffer;
   Boolean success;

   g_return_val_if_fail (str != NULL, NULL);

   length = CFStringGetLength (str);
   maxlen = CFStringGetMaximumSizeForEncoding (length, kCFStringEncodingUTF8);
   buffer = g_malloc (maxlen + 1);
   success = CFStringGetCString (str, (char *) buffer, maxlen,
                                 kCFStringEncodingUTF8);
   CFRelease (str);
   if (success)
     return buffer;
   else
     {
       g_free (buffer);
       return NULL;
     }
 }

 /*< internal >
  * create_cstr_from_cfstring_with_fallback:
  * @str: a #CFStringRef
  * @fallback: a #gchar
  *
  * Tries to convert a cfstring to a utf8 cstring.
  * If @str is NULL or conversion fails @fallback is returned.
  * The incoming cfstring is released for you.
  * The returned string must be g_free()'d.
  *
  */
 static gchar *
 create_cstr_from_cfstring_with_fallback (CFStringRef  str,
                                          const gchar *fallback)
 {
   gchar *cstr = NULL;

   if (str)
     cstr = create_cstr_from_cfstring (str);
   if (!cstr)
     return g_strdup (fallback);

   return cstr;
 }

 /*< private >*/
 void
 g_content_type_set_mime_dirs (const gchar * const *dirs)
 {
   /* noop on macOS */
 }

 /*< private >*/
 const gchar * const *
 g_content_type_get_mime_dirs (void)
 {
   const gchar * const *mime_dirs = { NULL };
   return mime_dirs;
 }

 gboolean
 g_content_type_equals (const gchar *type1,
                        const gchar *type2)
 {
   CFStringRef str1, str2;
   gboolean ret;

   g_return_val_if_fail (type1 != NULL, FALSE);
   g_return_val_if_fail (type2 != NULL, FALSE);

   if (g_ascii_strcasecmp (type1, type2) == 0)
     return TRUE;

   str1 = create_cfstring_from_cstr (type1);
   str2 = create_cfstring_from_cstr (type2);

   ret = UTTypeEqual (str1, str2);

   CFRelease (str1);
   CFRelease (str2);

   return ret;
 }

 gboolean
 g_content_type_is_a (const gchar *ctype,
                      const gchar *csupertype)
 {
   CFStringRef type, supertype;
   gboolean ret;

   g_return_val_if_fail (ctype != NULL, FALSE);
   g_return_val_if_fail (csupertype != NULL, FALSE);

   type = create_cfstring_from_cstr (ctype);
   supertype = create_cfstring_from_cstr (csupertype);

   ret = UTTypeConformsTo (type, supertype);

   CFRelease (type);
   CFRelease (supertype);

   return ret;
 }

 gboolean
 g_content_type_is_mime_type (const gchar *type,
                              const gchar *mime_type)
 {
   gchar *content_type;
   gboolean ret;

   g_return_val_if_fail (type != NULL, FALSE);
   g_return_val_if_fail (mime_type != NULL, FALSE);

   content_type = g_content_type_from_mime_type (mime_type);
   ret = g_content_type_is_a (type, content_type);
   g_free (content_type);

   return ret;
 }

 gboolean
 g_content_type_is_unknown (const gchar *type)
 {
   g_return_val_if_fail (type != NULL, FALSE);

   /* Should dynamic types be considered "unknown"? */
   if (g_str_has_prefix (type, "dyn."))
     return TRUE;
   /* application/octet-stream */
   else if (g_strcmp0 (type, "public.data") == 0)
     return TRUE;

   return FALSE;
 }

 gchar *
 g_content_type_get_description (const gchar *type)
 {
   CFStringRef str;
   CFStringRef desc_str;

   g_return_val_if_fail (type != NULL, NULL);

   str = create_cfstring_from_cstr (type);
   desc_str = UTTypeCopyDescription (str);

   CFRelease (str);
   return create_cstr_from_cfstring_with_fallback (desc_str, "unknown");
 }

 /* <internal>
  * _get_generic_icon_name_from_mime_type
  *
  * This function produces a generic icon name from a @mime_type.
  * If no generic icon name is found in the xdg mime database, the
  * generic icon name is constructed.
  *
  * Background:
  * generic-icon elements specify the icon to use as a generic icon for this
  * particular mime-type, given by the name attribute. This is used if there
  * is no specific icon (see icon for how these are found). These are used
  * for categories of similar types (like spreadsheets or archives) that can
  * use a common icon. The Icon Naming Specification lists a set of such
  * icon names. If this element is not specified then the mimetype is used
  * to generate the generic icon by using the top-level media type
  * (e.g. "video" in "video/ogg") and appending "-x-generic"
  * (i.e. "video-x-generic" in the previous example).
  *
  * From: https://specifications.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-0.18.html
  */

 static gchar *
 _get_generic_icon_name_from_mime_type (const gchar *mime_type)
 {
   const gchar *xdg_icon_name;
   gchar *icon_name;

   G_LOCK (gio_xdgmime);
   xdg_icon_name = xdg_mime_get_generic_icon (mime_type);
   G_UNLOCK (gio_xdgmime);

   if (xdg_icon_name == NULL)
     {
       const char *p;
       const char *suffix = "-x-generic";
       gsize prefix_len;

       p = strchr (mime_type, '/');
       if (p == NULL)
         prefix_len = strlen (mime_type);
       else
         prefix_len = p - mime_type;

       icon_name = g_malloc (prefix_len + strlen (suffix) + 1);
       memcpy (icon_name, mime_type, prefix_len);
       memcpy (icon_name + prefix_len, suffix, strlen (suffix));
       icon_name[prefix_len + strlen (suffix)] = 0;
     }
   else
     {
       icon_name = g_strdup (xdg_icon_name);
     }

   return icon_name;
 }


 static GIcon *
 g_content_type_get_icon_internal (const gchar *uti,
                                   gboolean     symbolic)
 {
   char *mimetype_icon;
   char *mime_type;
   char *generic_mimetype_icon = NULL;
   char *q;
   char *icon_names[6];
   int n = 0;
   GIcon *themed_icon;
   const char  *xdg_icon;
   int i;

   g_return_val_if_fail (uti != NULL, NULL);

   mime_type = g_content_type_get_mime_type (uti);

   G_LOCK (gio_xdgmime);
   xdg_icon = xdg_mime_get_icon (mime_type);
   G_UNLOCK (gio_xdgmime);

   if (xdg_icon)
     icon_names[n++] = g_strdup (xdg_icon);

   mimetype_icon = g_strdup (mime_type);
   while ((q = strchr (mimetype_icon, '/')) != NULL)
     *q = '-';

   icon_names[n++] = mimetype_icon;

   generic_mimetype_icon = _get_generic_icon_name_from_mime_type (mime_type);

   if (generic_mimetype_icon)
     icon_names[n++] = generic_mimetype_icon;

   if (symbolic)
     {
       for (i = 0; i < n; i++)
         {
           icon_names[n + i] = icon_names[i];
           icon_names[i] = g_strconcat (icon_names[i], "-symbolic", NULL);
         }

       n += n;
     }

   themed_icon = g_themed_icon_new_from_names (icon_names, n);

   for (i = 0; i < n; i++)
     g_free (icon_names[i]);

   g_free(mime_type);

   return themed_icon;
 }

 GIcon *
 g_content_type_get_icon (const gchar *type)
 {
   return g_content_type_get_icon_internal (type, FALSE);
 }

 GIcon *
 g_content_type_get_symbolic_icon (const gchar *type)
 {
   return g_content_type_get_icon_internal (type, TRUE);
 }

 gchar *
 g_content_type_get_generic_icon_name (const gchar *type)
 {
   return NULL;
 }

 gboolean
 g_content_type_can_be_executable (const gchar *type)
 {
   CFStringRef uti;
   gboolean ret = FALSE;

   g_return_val_if_fail (type != NULL, FALSE);

   uti = create_cfstring_from_cstr (type);

   if (UTTypeConformsTo (uti, kUTTypeApplication))
     ret = TRUE;
   else if (UTTypeConformsTo (uti, CFSTR("public.executable")))
     ret = TRUE;
   else if (UTTypeConformsTo (uti, CFSTR("public.script")))
     ret = TRUE;
   /* Our tests assert that all text can be executable... */
   else if (UTTypeConformsTo (uti, CFSTR("public.text")))
       ret = TRUE;

   CFRelease (uti);
   return ret;
 }

 gchar *
 g_content_type_from_mime_type (const gchar *mime_type)
 {
   CFStringRef mime_str;
   CFStringRef uti_str;

   g_return_val_if_fail (mime_type != NULL, NULL);

   /* Their api does not handle globs but they are common. */
   if (g_str_has_suffix (mime_type, "*"))
     {
       if (g_str_has_prefix (mime_type, "audio"))
         return g_strdup ("public.audio");
       if (g_str_has_prefix (mime_type, "image"))
         return g_strdup ("public.image");
       if (g_str_has_prefix (mime_type, "text"))
         return g_strdup ("public.text");
       if (g_str_has_prefix (mime_type, "video"))
         return g_strdup ("public.movie");
     }

   /* Some exceptions are needed for gdk-pixbuf.
    * This list is not exhaustive.
    */
   if (g_str_has_prefix (mime_type, "image"))
     {
       if (g_str_has_suffix (mime_type, "x-icns"))
         return g_strdup ("com.apple.icns");
       if (g_str_has_suffix (mime_type, "x-tga"))
         return g_strdup ("com.truevision.tga-image");
       if (g_str_has_suffix (mime_type, "x-ico"))
         return g_strdup ("com.microsoft.ico ");
     }

   /* These are also not supported...
    * Used in glocalfileinfo.c
    */
   if (g_str_has_prefix (mime_type, "inode"))
     {
       if (g_str_has_suffix (mime_type, "directory"))
         return g_strdup ("public.folder");
       if (g_str_has_suffix (mime_type, "symlink"))
         return g_strdup ("public.symlink");
     }

   /* This is correct according to the Apple docs:
      https://developer.apple.com/library/content/documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html
   */
   if (strcmp (mime_type, "text/plain") == 0)
     return g_strdup ("public.text");

   /* I don’t know of an appropriate equivalent for application/x-zerosize, but
    * historically GLib has returned public.text for zero-sized files, so let’s
    * continue doing that. */
   if (strcmp (mime_type, "application/x-zerosize") == 0)
     return g_strdup ("public.text");

   /* Non standard type */
   if (strcmp (mime_type, "application/x-executable") == 0)
     return g_strdup ("public.executable");

   mime_str = create_cfstring_from_cstr (mime_type);
   uti_str = UTTypeCreatePreferredIdentifierForTag (kUTTagClassMIMEType, mime_str, NULL);

   CFRelease (mime_str);
   return create_cstr_from_cfstring_with_fallback (uti_str, "public.data");
 }

 gchar *
 g_content_type_get_mime_type (const gchar *type)
 {
   CFStringRef uti_str;
   CFStringRef mime_str;

   g_return_val_if_fail (type != NULL, NULL);

   /* We must match the additions above
    * so conversions back and forth work.
    */
   if (g_str_has_prefix (type, "public"))
     {
       if (g_str_has_suffix (type, ".image"))
         return g_strdup ("image/*");
       if (g_str_has_suffix (type, ".movie"))
         return g_strdup ("video/*");
       if (g_str_has_suffix (type, ".text"))
         return g_strdup ("text/*");
       if (g_str_has_suffix (type, ".audio"))
         return g_strdup ("audio/*");
       if (g_str_has_suffix (type, ".folder"))
         return g_strdup ("inode/directory");
       if (g_str_has_suffix (type, ".symlink"))
         return g_strdup ("inode/symlink");
       if (g_str_has_suffix (type, ".executable"))
         return g_strdup ("application/x-executable");
     }

   uti_str = create_cfstring_from_cstr (type);
   mime_str = UTTypeCopyPreferredTagWithClass(uti_str, kUTTagClassMIMEType);

   CFRelease (uti_str);
   return create_cstr_from_cfstring_with_fallback (mime_str, "application/octet-stream");
 }

 static gboolean
 looks_like_text (const guchar *data,
                  gsize         data_size)
 {
   gsize i;
   guchar c;

   for (i = 0; i < data_size; i++)
     {
       c = data[i];
       if (g_ascii_iscntrl (c) && !g_ascii_isspace (c) && c != '\b')
         return FALSE;
     }
   return TRUE;
 }

 gchar *
 g_content_type_guess (const gchar  *filename,
                       const guchar *data,
                       gsize         data_size,
                       gboolean     *result_uncertain)
 {
   CFStringRef uti = NULL;
   gchar *cextension;
   CFStringRef extension;
   int uncertain = -1;

   g_return_val_if_fail (data_size != (gsize) -1, NULL);

   if (filename && *filename)
     {
       gchar *basename = g_path_get_basename (filename);
       gchar *dirname = g_path_get_dirname (filename);
       gsize i = strlen (filename);

       if (filename[i - 1] == '/')
         {
           if (g_strcmp0 (dirname, "/Volumes") == 0)
             {
               uti = CFStringCreateCopy (NULL, kUTTypeVolume);
             }
           else if ((cextension = strrchr (basename, '.')) != NULL)
             {
               cextension++;
               extension = create_cfstring_from_cstr (cextension);
               uti = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension,
                                                            extension, NULL);
               CFRelease (extension);

               if (CFStringHasPrefix (uti, CFSTR ("dyn.")))
                 {
                   CFRelease (uti);
                   uti = CFStringCreateCopy (NULL, kUTTypeFolder);
                   uncertain = TRUE;
                 }
             }
           else
             {
               uti = CFStringCreateCopy (NULL, kUTTypeFolder);
               uncertain = TRUE; /* Matches Unix backend */
             }
         }
       else
         {
           /* GTK needs this... */
           if (g_str_has_suffix (basename, ".ui"))
             {
               uti = CFStringCreateCopy (NULL, kUTTypeXML);
             }
           else if (g_str_has_suffix (basename, ".txt"))
             {
               uti = CFStringCreateCopy (NULL, CFSTR ("public.text"));
             }
           else if ((cextension = strrchr (basename, '.')) != NULL)
             {
               cextension++;
               extension = create_cfstring_from_cstr (cextension);
               uti = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension,
                                                            extension, NULL);
               CFRelease (extension);
             }
           g_free (basename);
           g_free (dirname);
         }
     }
   if (data && (!filename || !uti ||
                CFStringCompare (uti, CFSTR ("public.data"), 0) == kCFCompareEqualTo))
     {
       const char *sniffed_mimetype;
       G_LOCK (gio_xdgmime);
       sniffed_mimetype = xdg_mime_get_mime_type_for_data (data, data_size, NULL);
       G_UNLOCK (gio_xdgmime);
       if (sniffed_mimetype != XDG_MIME_TYPE_UNKNOWN)
         {
           gchar *uti_str = g_content_type_from_mime_type (sniffed_mimetype);
           uti = create_cfstring_from_cstr (uti_str);
           g_free (uti_str);
         }
       if (!uti && looks_like_text (data, data_size))
         {
           if (g_str_has_prefix ((const gchar*)data, "#!/"))
             uti = CFStringCreateCopy (NULL, CFSTR ("public.script"));
           else
             uti = CFStringCreateCopy (NULL, CFSTR ("public.text"));
         }
     }

   if (!uti)
     {
       /* Generic data type */
       uti = CFStringCreateCopy (NULL, CFSTR ("public.data"));
       if (result_uncertain)
         *result_uncertain = TRUE;
     }
   else if (result_uncertain)
     {
       *result_uncertain = uncertain == -1 ? FALSE : uncertain;
     }

   return create_cstr_from_cfstring (uti);
 }

 GList *
 g_content_types_get_registered (void)
 {
   /* TODO: UTTypeCreateAllIdentifiersForTag? */
   return NULL;
 }

 gchar **
 g_content_type_guess_for_tree (GFile *root)
 {
   return NULL;
 }
	/* GIO - GLib Input, Output and Streaming Library
	*
	* Copyright (C) 2014 Patrick Griffis
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General
	* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
	*
	*/

	#include "config.h"

	#include "gcontenttype.h"
	#include "gicon.h"
	#include "gthemedicon.h"

	#include <CoreServices/CoreServices.h>

	#define XDG_PREFIX _gio_xdg
	#include "xdgmime/xdgmime.h"

	/* We lock this mutex whenever we modify global state in this module. */
	G_LOCK_DEFINE_STATIC (gio_xdgmime);


	/*< internal >
	* create_cfstring_from_cstr:
	* @cstr: a #gchar
	*
	* Converts a cstr to a utf8 cfstring
	* It must be CFReleased()'d.
	*
	*/
	static CFStringRef
	create_cfstring_from_cstr (const gchar *cstr)
	{
	return CFStringCreateWithCString (NULL, cstr, kCFStringEncodingUTF8);
	}

	/*< internal >
	* create_cstr_from_cfstring:
	* @str: a #CFStringRef
	*
	* Converts a cfstring to a utf8 cstring.
	* The incoming cfstring is released for you.
	* The returned string must be g_free()'d.
	*
	*/
	static gchar *
	create_cstr_from_cfstring (CFStringRef str)
	{
	CFIndex length;
	CFIndex maxlen;
	gchar *buffer;
	Boolean success;

	g_return_val_if_fail (str != NULL, NULL);

	length = CFStringGetLength (str);
	maxlen = CFStringGetMaximumSizeForEncoding (length, kCFStringEncodingUTF8);
	buffer = g_malloc (maxlen + 1);
	success = CFStringGetCString (str, (char *) buffer, maxlen,
	kCFStringEncodingUTF8);
	CFRelease (str);
	if (success)
	return buffer;
	else
	{
	g_free (buffer);
	return NULL;
	}
	}

	/*< internal >
	* create_cstr_from_cfstring_with_fallback:
	* @str: a #CFStringRef
	* @fallback: a #gchar
	*
	* Tries to convert a cfstring to a utf8 cstring.
	* If @str is NULL or conversion fails @fallback is returned.
	* The incoming cfstring is released for you.
	* The returned string must be g_free()'d.
	*
	*/
	static gchar *
	create_cstr_from_cfstring_with_fallback (CFStringRef str,
	const gchar *fallback)
	{
	gchar *cstr = NULL;

	if (str)
	cstr = create_cstr_from_cfstring (str);
	if (!cstr)
	return g_strdup (fallback);

	return cstr;
	}

	/< private >/
	void
	g_content_type_set_mime_dirs (const gchar * const *dirs)
	{
	/* noop on macOS */
	}

	/< private >/
	const gchar * const *
	g_content_type_get_mime_dirs (void)
	{
	const gchar * const *mime_dirs = { NULL };
	return mime_dirs;
	}

	gboolean
	g_content_type_equals (const gchar *type1,
	const gchar *type2)
	{
	CFStringRef str1, str2;
	gboolean ret;

	g_return_val_if_fail (type1 != NULL, FALSE);
	g_return_val_if_fail (type2 != NULL, FALSE);

	if (g_ascii_strcasecmp (type1, type2) == 0)
	return TRUE;

	str1 = create_cfstring_from_cstr (type1);
	str2 = create_cfstring_from_cstr (type2);

	ret = UTTypeEqual (str1, str2);

	CFRelease (str1);
	CFRelease (str2);

	return ret;
	}

	gboolean
	g_content_type_is_a (const gchar *ctype,
	const gchar *csupertype)
	{
	CFStringRef type, supertype;
	gboolean ret;

	g_return_val_if_fail (ctype != NULL, FALSE);
	g_return_val_if_fail (csupertype != NULL, FALSE);

	type = create_cfstring_from_cstr (ctype);
	supertype = create_cfstring_from_cstr (csupertype);

	ret = UTTypeConformsTo (type, supertype);

	CFRelease (type);
	CFRelease (supertype);

	return ret;
	}

	gboolean
	g_content_type_is_mime_type (const gchar *type,
	const gchar *mime_type)
	{
	gchar *content_type;
	gboolean ret;

	g_return_val_if_fail (type != NULL, FALSE);
	g_return_val_if_fail (mime_type != NULL, FALSE);

	content_type = g_content_type_from_mime_type (mime_type);
	ret = g_content_type_is_a (type, content_type);
	g_free (content_type);

	return ret;
	}

	gboolean
	g_content_type_is_unknown (const gchar *type)
	{
	g_return_val_if_fail (type != NULL, FALSE);

	/* Should dynamic types be considered "unknown"? */
	if (g_str_has_prefix (type, "dyn."))
	return TRUE;
	/* application/octet-stream */
	else if (g_strcmp0 (type, "public.data") == 0)
	return TRUE;

	return FALSE;
	}

	gchar *
	g_content_type_get_description (const gchar *type)
	{
	CFStringRef str;
	CFStringRef desc_str;

	g_return_val_if_fail (type != NULL, NULL);

	str = create_cfstring_from_cstr (type);
	desc_str = UTTypeCopyDescription (str);

	CFRelease (str);
	return create_cstr_from_cfstring_with_fallback (desc_str, "unknown");
	}

	/* <internal>
	* _get_generic_icon_name_from_mime_type
	*
	* This function produces a generic icon name from a @mime_type.
	* If no generic icon name is found in the xdg mime database, the
	* generic icon name is constructed.
	*
	* Background:
	* generic-icon elements specify the icon to use as a generic icon for this
	* particular mime-type, given by the name attribute. This is used if there
	* is no specific icon (see icon for how these are found). These are used
	* for categories of similar types (like spreadsheets or archives) that can
	* use a common icon. The Icon Naming Specification lists a set of such
	* icon names. If this element is not specified then the mimetype is used
	* to generate the generic icon by using the top-level media type
	* (e.g. "video" in "video/ogg") and appending "-x-generic"
	* (i.e. "video-x-generic" in the previous example).
	*
	* From: https://specifications.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-0.18.html
	*/

	static gchar *
	_get_generic_icon_name_from_mime_type (const gchar *mime_type)
	{
	const gchar *xdg_icon_name;
	gchar *icon_name;

	G_LOCK (gio_xdgmime);
	xdg_icon_name = xdg_mime_get_generic_icon (mime_type);
	G_UNLOCK (gio_xdgmime);

	if (xdg_icon_name == NULL)
	{
	const char *p;
	const char *suffix = "-x-generic";
	gsize prefix_len;

	p = strchr (mime_type, '/');
	if (p == NULL)
	prefix_len = strlen (mime_type);
	else
	prefix_len = p - mime_type;

	icon_name = g_malloc (prefix_len + strlen (suffix) + 1);
	memcpy (icon_name, mime_type, prefix_len);
	memcpy (icon_name + prefix_len, suffix, strlen (suffix));
	icon_name[prefix_len + strlen (suffix)] = 0;
	}
	else
	{
	icon_name = g_strdup (xdg_icon_name);
	}

	return icon_name;
	}


	static GIcon *
	g_content_type_get_icon_internal (const gchar *uti,
	gboolean symbolic)
	{
	char *mimetype_icon;
	char *mime_type;
	char *generic_mimetype_icon = NULL;
	char *q;
	char *icon_names[6];
	int n = 0;
	GIcon *themed_icon;
	const char *xdg_icon;
	int i;

	g_return_val_if_fail (uti != NULL, NULL);

	mime_type = g_content_type_get_mime_type (uti);

	G_LOCK (gio_xdgmime);
	xdg_icon = xdg_mime_get_icon (mime_type);
	G_UNLOCK (gio_xdgmime);

	if (xdg_icon)
	icon_names[n++] = g_strdup (xdg_icon);

	mimetype_icon = g_strdup (mime_type);
	while ((q = strchr (mimetype_icon, '/')) != NULL)
	*q = '-';

	icon_names[n++] = mimetype_icon;

	generic_mimetype_icon = _get_generic_icon_name_from_mime_type (mime_type);

	if (generic_mimetype_icon)
	icon_names[n++] = generic_mimetype_icon;

	if (symbolic)
	{
	for (i = 0; i < n; i++)
	{
	icon_names[n + i] = icon_names[i];
	icon_names[i] = g_strconcat (icon_names[i], "-symbolic", NULL);
	}

	n += n;
	}

	themed_icon = g_themed_icon_new_from_names (icon_names, n);

	for (i = 0; i < n; i++)
	g_free (icon_names[i]);

	g_free(mime_type);

	return themed_icon;
	}

	GIcon *
	g_content_type_get_icon (const gchar *type)
	{
	return g_content_type_get_icon_internal (type, FALSE);
	}

	GIcon *
	g_content_type_get_symbolic_icon (const gchar *type)
	{
	return g_content_type_get_icon_internal (type, TRUE);
	}

	gchar *
	g_content_type_get_generic_icon_name (const gchar *type)
	{
	return NULL;
	}

	gboolean
	g_content_type_can_be_executable (const gchar *type)
	{
	CFStringRef uti;
	gboolean ret = FALSE;

	g_return_val_if_fail (type != NULL, FALSE);

	uti = create_cfstring_from_cstr (type);

	if (UTTypeConformsTo (uti, kUTTypeApplication))
	ret = TRUE;
	else if (UTTypeConformsTo (uti, CFSTR("public.executable")))
	ret = TRUE;
	else if (UTTypeConformsTo (uti, CFSTR("public.script")))
	ret = TRUE;
	/* Our tests assert that all text can be executable... */
	else if (UTTypeConformsTo (uti, CFSTR("public.text")))
	ret = TRUE;

	CFRelease (uti);
	return ret;
	}

	gchar *
	g_content_type_from_mime_type (const gchar *mime_type)
	{
	CFStringRef mime_str;
	CFStringRef uti_str;

	g_return_val_if_fail (mime_type != NULL, NULL);

	/* Their api does not handle globs but they are common. */
	if (g_str_has_suffix (mime_type, "*"))
	{
	if (g_str_has_prefix (mime_type, "audio"))
	return g_strdup ("public.audio");
	if (g_str_has_prefix (mime_type, "image"))
	return g_strdup ("public.image");
	if (g_str_has_prefix (mime_type, "text"))
	return g_strdup ("public.text");
	if (g_str_has_prefix (mime_type, "video"))
	return g_strdup ("public.movie");
	}

	/* Some exceptions are needed for gdk-pixbuf.
	* This list is not exhaustive.
	*/
	if (g_str_has_prefix (mime_type, "image"))
	{
	if (g_str_has_suffix (mime_type, "x-icns"))
	return g_strdup ("com.apple.icns");
	if (g_str_has_suffix (mime_type, "x-tga"))
	return g_strdup ("com.truevision.tga-image");
	if (g_str_has_suffix (mime_type, "x-ico"))
	return g_strdup ("com.microsoft.ico ");
	}

	/* These are also not supported...
	* Used in glocalfileinfo.c
	*/
	if (g_str_has_prefix (mime_type, "inode"))
	{
	if (g_str_has_suffix (mime_type, "directory"))
	return g_strdup ("public.folder");
	if (g_str_has_suffix (mime_type, "symlink"))
	return g_strdup ("public.symlink");
	}

	/* This is correct according to the Apple docs:
	https://developer.apple.com/library/content/documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html
	*/
	if (strcmp (mime_type, "text/plain") == 0)
	return g_strdup ("public.text");

	/* I don’t know of an appropriate equivalent for application/x-zerosize, but
	* historically GLib has returned public.text for zero-sized files, so let’s
	* continue doing that. */
	if (strcmp (mime_type, "application/x-zerosize") == 0)
	return g_strdup ("public.text");

	/* Non standard type */
	if (strcmp (mime_type, "application/x-executable") == 0)
	return g_strdup ("public.executable");

	mime_str = create_cfstring_from_cstr (mime_type);
	uti_str = UTTypeCreatePreferredIdentifierForTag (kUTTagClassMIMEType, mime_str, NULL);

	CFRelease (mime_str);
	return create_cstr_from_cfstring_with_fallback (uti_str, "public.data");
	}

	gchar *
	g_content_type_get_mime_type (const gchar *type)
	{
	CFStringRef uti_str;
	CFStringRef mime_str;

	g_return_val_if_fail (type != NULL, NULL);

	/* We must match the additions above
	* so conversions back and forth work.
	*/
	if (g_str_has_prefix (type, "public"))
	{
	if (g_str_has_suffix (type, ".image"))
	return g_strdup ("image/*");
	if (g_str_has_suffix (type, ".movie"))
	return g_strdup ("video/*");
	if (g_str_has_suffix (type, ".text"))
	return g_strdup ("text/*");
	if (g_str_has_suffix (type, ".audio"))
	return g_strdup ("audio/*");
	if (g_str_has_suffix (type, ".folder"))
	return g_strdup ("inode/directory");
	if (g_str_has_suffix (type, ".symlink"))
	return g_strdup ("inode/symlink");
	if (g_str_has_suffix (type, ".executable"))
	return g_strdup ("application/x-executable");
	}

	uti_str = create_cfstring_from_cstr (type);
	mime_str = UTTypeCopyPreferredTagWithClass(uti_str, kUTTagClassMIMEType);

	CFRelease (uti_str);
	return create_cstr_from_cfstring_with_fallback (mime_str, "application/octet-stream");
	}

	static gboolean
	looks_like_text (const guchar *data,
	gsize data_size)
	{
	gsize i;
	guchar c;

	for (i = 0; i < data_size; i++)
	{
	c = data[i];
	if (g_ascii_iscntrl (c) && !g_ascii_isspace (c) && c != '\b')
	return FALSE;
	}
	return TRUE;
	}

	gchar *
	g_content_type_guess (const gchar *filename,
	const guchar *data,
	gsize data_size,
	gboolean *result_uncertain)
	{
	CFStringRef uti = NULL;
	gchar *cextension;
	CFStringRef extension;
	int uncertain = -1;

	g_return_val_if_fail (data_size != (gsize) -1, NULL);

	if (filename && *filename)
	{
	gchar *basename = g_path_get_basename (filename);
	gchar *dirname = g_path_get_dirname (filename);
	gsize i = strlen (filename);

	if (filename[i - 1] == '/')
	{
	if (g_strcmp0 (dirname, "/Volumes") == 0)
	{
	uti = CFStringCreateCopy (NULL, kUTTypeVolume);
	}
	else if ((cextension = strrchr (basename, '.')) != NULL)
	{
	cextension++;
	extension = create_cfstring_from_cstr (cextension);
	uti = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension,
	extension, NULL);
	CFRelease (extension);

	if (CFStringHasPrefix (uti, CFSTR ("dyn.")))
	{
	CFRelease (uti);
	uti = CFStringCreateCopy (NULL, kUTTypeFolder);
	uncertain = TRUE;
	}
	}
	else
	{
	uti = CFStringCreateCopy (NULL, kUTTypeFolder);
	uncertain = TRUE; /* Matches Unix backend */
	}
	}
	else
	{
	/* GTK needs this... */
	if (g_str_has_suffix (basename, ".ui"))
	{
	uti = CFStringCreateCopy (NULL, kUTTypeXML);
	}
	else if (g_str_has_suffix (basename, ".txt"))
	{
	uti = CFStringCreateCopy (NULL, CFSTR ("public.text"));
	}
	else if ((cextension = strrchr (basename, '.')) != NULL)
	{
	cextension++;
	extension = create_cfstring_from_cstr (cextension);
	uti = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension,
	extension, NULL);
	CFRelease (extension);
	}
	g_free (basename);
	g_free (dirname);
	}
	}
	if (data && (!filename \|\| !uti \|\|
	CFStringCompare (uti, CFSTR ("public.data"), 0) == kCFCompareEqualTo))
	{
	const char *sniffed_mimetype;
	G_LOCK (gio_xdgmime);
	sniffed_mimetype = xdg_mime_get_mime_type_for_data (data, data_size, NULL);
	G_UNLOCK (gio_xdgmime);
	if (sniffed_mimetype != XDG_MIME_TYPE_UNKNOWN)
	{
	gchar *uti_str = g_content_type_from_mime_type (sniffed_mimetype);
	uti = create_cfstring_from_cstr (uti_str);
	g_free (uti_str);
	}
	if (!uti && looks_like_text (data, data_size))
	{
	if (g_str_has_prefix ((const gchar*)data, "#!/"))
	uti = CFStringCreateCopy (NULL, CFSTR ("public.script"));
	else
	uti = CFStringCreateCopy (NULL, CFSTR ("public.text"));
	}
	}

	if (!uti)
	{
	/* Generic data type */
	uti = CFStringCreateCopy (NULL, CFSTR ("public.data"));
	if (result_uncertain)
	*result_uncertain = TRUE;
	}
	else if (result_uncertain)
	{
	*result_uncertain = uncertain == -1 ? FALSE : uncertain;
	}

	return create_cstr_from_cfstring (uti);
	}

	GList *
	g_content_types_get_registered (void)
	{
	/* TODO: UTTypeCreateAllIdentifiersForTag? */
	return NULL;
	}

	gchar **
	g_content_type_guess_for_tree (GFile *root)
	{
	return NULL;
	}