background: Only show the image types we support

And add image/bmp to those types.

https://bugzilla.gnome.org/show_bug.cgi?id=669960

panels/background/bg-pictures-source.c

@@ -46,6 +46,14 @@ struct _BgPicturesSourcePrivate
   GHashTable *known_items;
 };
 
+const char * const content_types[] = {
+	"image/png",
+	"image/jpeg",
+	"image/bmp",
+	"image/svg+xml",
+	NULL
+};
+
 static char *bg_pictures_source_get_unique_filename (const char *uri);
 
 static void
@@ -280,6 +288,16 @@ picture_opened_for_read (GObject *source_object,
   g_object_unref (stream);
 }
 
+static gboolean
+in_content_types (const char *content_type)
+{
+	guint i;
+	for (i = 0; content_types[i]; i++)
+		if (g_str_equal (content_types[i], content_type))
+			return TRUE;
+	return FALSE;
+}
+
 static gboolean
 add_single_file (BgPicturesSource *bg_source,
 		 GFile            *file,
@@ -287,19 +305,16 @@ add_single_file (BgPicturesSource *bg_source,
 		 const char       *source_uri)
 {
   const gchar *content_type;
+  CcBackgroundItem *item;
+  char *uri;
 
   /* find png and jpeg files */
   content_type = g_file_info_get_content_type (info);
 
   if (!content_type)
     return FALSE;
-
-  if (g_str_equal ("image/png", content_type) ||
-      g_str_equal ("image/jpeg", content_type) ||
-      g_str_equal ("image/svg+xml", content_type))
-    {
-      CcBackgroundItem *item;
-      char *uri;
+  if (!in_content_types (content_type))
+    return FALSE;
 
   /* create a new CcBackgroundItem */
   uri = g_file_get_uri (file);
@@ -317,9 +332,6 @@ add_single_file (BgPicturesSource *bg_source,
   g_file_read_async (file, 0, NULL, picture_opened_for_read, bg_source);
   g_object_unref (file);
   return TRUE;
-    }
-
-  return FALSE;
 }
 
 gboolean
@@ -554,3 +566,8 @@ bg_pictures_source_new (void)
   return g_object_new (BG_TYPE_PICTURES_SOURCE, NULL);
 }
 
+const char * const *
+bg_pictures_get_support_content_types (void)
+{
+	return content_types;
+}

panels/background/bg-pictures-source.h

@@ -80,6 +80,8 @@ gboolean          bg_pictures_source_remove         (BgPicturesSource *bg_source
 gboolean          bg_pictures_source_is_known       (BgPicturesSource *bg_source,
 						     const char       *uri);
 
+const char * const * bg_pictures_get_support_content_types (void);
+
 G_END_DECLS
 
 #endif /* _BG_PICTURES_SOURCE_H */

panels/background/cc-background-panel.c

@@ -992,11 +992,15 @@ add_button_clicked (GtkButton         *button,
   GtkWidget *preview;
   GtkFileFilter *filter;
   CcBackgroundPanelPrivate *priv;
+  const char * const * content_types;
+  guint i;
 
   priv = panel->priv;
 
   filter = gtk_file_filter_new ();
-  gtk_file_filter_add_mime_type (filter, "image/*");
+  content_types = bg_pictures_get_support_content_types ();
+  for (i = 0; content_types[i] != NULL; i++)
+    gtk_file_filter_add_mime_type (filter, content_types[i]);
 
   chooser = gtk_file_chooser_dialog_new (_("Browse for more pictures"),
 					 GTK_WINDOW (gtk_widget_get_toplevel (WID ("background-panel"))),