Gio – 2.0: Migrating from GnomeVFS to GIO
Description: Reference for Gio-2.0: Migrating from GnomeVFS to GIO

#### Migrating from GnomeVFS to GIO

## Comparison of GnomeVFS and GIO concepts

GnomeVFS | GIO
--- | ---
`GnomeVFSURI` | `GFile`
`GnomeVFSFileInfo` | `GFileInfo`
`GnomeVFSResult` | `GError`, with `G_IO_ERROR` values
`GnomeVFSHandle` & `GnomeVFSAsyncHandle` | `GInputStream` or `GOutputStream`
`GnomeVFSDirectoryHandle` | `GFileEnumerator`
MIME type | content type
`GnomeVFSMonitor` | `GFileMonitor`
`GnomeVFSVolumeMonitor` | `GVolumeMonitor`
`GnomeVFSVolume` | `GMount`
`GnomeVFSDrive` | `GVolume`
- | `GDrive`
`GnomeVFSContext` | `GCancellable`
`gnome_vfs_async_cancel()` | `g_cancellable_cancel()`

## Trash handling

The handling of trashed files has been changed in GIO, compared to gnome-vfs. gnome-vfs has a home-grown trash implementation that predates the freedesktop.org Desktop Trash Can specification that is implemented in GIO. The location for storing trashed files has changed from `$HOME/.Trash` to `$HOME/.local/share/Trash` (or more correctly `$XDG_DATA_HOME/Trash`), which means that there is a need for migrating files that have been trashed by gnome-vfs to the new location.

In gnome-vfs, the `trash://` scheme offering a merged view of all trash directories was implemented in Nautilus, and trash-handling applications had to find and monitor all trash directories themselves. With GIO, the `trash://` implementation has been moved to gvfs and applications can simply monitor that location:

    static void
    file_changed (GFileMonitor      *file_monitor,
                  GFile             *child,
                  GFile             *other_file,
                  GFileMonitorEvent  event_type,
                  gpointer           user_data)
    {
      switch (event_type)
      {
      case G_FILE_MONITOR_EVENT_DELETED:
        g_print ("'%s' removed from trash\n", g_file_get_basename (child));
        break;
      case G_FILE_MONITOR_EVENT_CREATED:
        g_print ("'%s' added to trash\n", g_file_get_basename (child));
        break;
      default: ;
      }
    }

    static void
    start_monitoring_trash (void)
    {
      GFile *file;
      GFileMonitor *monitor;

      file = g_file_new_for_uri ("trash://");
      monitor = g_file_monitor_directory (file, 0, NULL, NULL);
      g_object_unref (file);

      g_signal_connect (monitor, "changed", G_CALLBACK (file_changed), NULL);

      /* ... */

    }

GIO exposes some useful metadata about trashed files. There are `trash::orig-path` and `trash::deletion-date` attributes. The `standard::icon` attribute of the `trash://` itself provides a suitable icon for displaying the trash can on the desktop. If you are using this icon, make sure to monitor this attribute for changes, since the icon may be updated to reflect that state of the trash can.

Moving a file to the trash is much simpler with GIO. Instead of using `gnome_vfs_find_directory()` with `GNOME_VFS_DIRECTORY_KIND_TRASH` to find out where to move the trashed file, just use the `g_file_trash()` method.

## Operations on multiple files

gnome-vfs has the dreaded `gnome_vfs_xfer_uri_list()` function which has tons of options and offers the equivalent of `cp`, `mv`, `ln`, `mkdir` and `rm` at the same time.

GIO offers a much simpler asynchronous task functionality instead, that lets you schedule a function to be called in a separate thread, making sure that updates are scheduled within the main context that created the task, so you can update your user interface. See: `GTask`.

## Mime monitoring

gnome-vfs offered a way to monitor the association between mime types and default handlers for changes, with the `GnomeVFSMIMEMonitor` object. GIO does not offer a replacement for this functionality at this time, since we have not found a compelling use case where `GnomeVFSMIMEMonitor` was used. If you think you have such a use case, please open an issue on the GLib issue tracker.