glib/docs/reference/gio/migrating-gnome-vfs.xml

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<chapter>
<title>Migrating from GnomeVFS to GIO</title>
<table id="gnome-vfs-vs-gio">
<title>Comparison of GnomeVFS and GIO concepts</title>
<tgroup cols="2">
<thead>
<row><entry>GnomeVFS</entry><entry>GIO</entry></row>
</thead>
<tbody>
<row><entry>GnomeVFSURI</entry><entry>GFile</entry></row>
<row><entry>GnomeVFSFileInfo</entry><entry>GFileInfo</entry></row>
<row><entry>GnomeVFSResult</entry><entry>GError, with G_IO_ERROR values</entry></row>
<row><entry>GnomeVFSHandle &amp; GnomeVFSAsyncHandle</entry><entry>GInputStream or GOutputStream</entry></row>
<row><entry>GnomeVFSDirectoryHandle</entry><entry>GFileEnumerator</entry></row>
<row><entry>mime type</entry><entry>content type</entry></row>
<row><entry>GnomeVFSMonitor</entry><entry>GFileMonitor</entry></row>
<row><entry>GnomeVFSVolumeMonitor</entry><entry>GVolumeMonitor</entry></row>
<row><entry>GnomeVFSVolume</entry><entry>GMount</entry></row>
<row><entry>GnomeVFSDrive</entry><entry>GVolume</entry></row>
<row><entry>-</entry><entry>GDrive</entry></row>
<row><entry>GnomeVFSContext</entry><entry>GCancellable</entry></row>
<row><entry>gnome_vfs_async_cancel</entry><entry>g_cancellable_cancel</entry></row>
</tbody>
</tgroup>
</table>
<section>
<title>Trash handling</title>
<para>
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 <ulink url="http://www.freedesktop.org/wiki/Specifications/trash-spec">Desktop Trash Can</ulink> specification
that is implemented in GIO. The location for storing trashed files
has changed from <filename>$HOME/.Trash</filename> to
<filename>$HOME/.local/share/Trash</filename> (or more correctly
<filename>$XDG_DATA_HOME/Trash</filename>), which means that
there is a need for migrating files that have been trashed by
gnome-vfs to the new location.
</para>
<para>
In gnome-vfs, the <filename>trash://</filename> 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 <filename>trash://</filename>
implementation has been moved to gvfs and applications can simply
monitor that location:
</para>
<informalexample><programlisting>
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);
/* ... */
}
</programlisting></informalexample>
<para>
GIO exposes some useful metadata about trashed files. There are
trash::orig-path and trash::deletion-date attributes. The
standard::icon attribute of the <filename>trash://</filename>
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.
</para>
<para>
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()
function.
</para>
</section>
<section>
<title>Operations on multiple files</title>
<para>
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.
</para>
<para>
GIO offers a much simpler I/O scheduler functionality instead, that
lets you schedule a function to be called in a separate thread, or
if threads are not available, as an idle in the mainloop.
See g_io_scheduler_push_job().
</para>
</section>
<section>
<title>Mime monitoring</title>
<para>
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 report it at
<ulink url="https://gitlab.gnome.org/GNOME/glib/issues/new">https://gitlab.gnome.org/GNOME/glib/issues/new</ulink>.
</para>
</section>
</chapter>