Bug 578178 – Show large previews for image files

Use the actual image from the file for expanded mode previews for image files. Use the pixbuf loader to set the appropriate image size as soon as the image is prepared, but before it is loaded, to avoid loading large images. Apply the pixbuf orientation setting so that the image is properly rotated. Preserve the original size of the image if its dimensions are smaller than the space available.

Make sure we provide the accurate available width for the details actor. This
width has to exclude the padding and border width. Also provide the available height for the details actor.

src/shell-global.h

@@ -36,6 +36,10 @@ gboolean shell_clutter_texture_set_from_pixbuf (ClutterTexture *texture,
 
 GdkPixbuf *shell_get_thumbnail_for_recent_info(GtkRecentInfo  *recent_info);
 
+GdkPixbuf *shell_create_pixbuf_from_image_file(const char *uri, 
+                                               int available_width, 
+                                               int available_height);
+
 GSList *shell_get_categories_for_desktop_file(const char *desktop_file_name);
 
 guint16 shell_get_event_key_symbol(ClutterEvent *event);