Class: Gio::FileEnumerator

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Instance Method Summary collapse

Instance Method Details

#close(cancellable) ⇒ Boolean

Releases all resources used by this enumerator, making the
enumerator return %G_IO_ERROR_CLOSED on all calls.

This will be automatically called when the last reference
is dropped, but you might want to call this function to make
sure resources are released as early as possible.

Parameters:

  • cancellable (Gio::Cancellable) —

    optional #GCancellable object, nil to ignore.

Returns:

  • (Boolean) —

    #TRUE on success or #FALSE on error.

#close_async(io_priority, cancellable, callback, user_data) ⇒ nil

Asynchronously closes the file enumerator.

If cancellable is not nil, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error %G_IO_ERROR_CANCELLED will be returned in
g_file_enumerator_close_finish().

Parameters:

  • io_priority (Integer) —

    the [I/O priority][io-priority] of the request

  • cancellable (Gio::Cancellable) —

    optional #GCancellable object, nil to ignore.

  • callback (Gio::AsyncReadyCallback) —

    a GAsync::ReadyCallback
    to call when the request is satisfied

  • user_data (GObject) —

    the data to pass to callback function

Returns:

  • (nil)

#close_finish(result) ⇒ Boolean

Finishes closing a file enumerator, started from g_file_enumerator_close_async().

If the file enumerator was already closed when g_file_enumerator_close_async()
was called, then this function will report %G_IO_ERROR_CLOSED in error, and
return false. If the file enumerator had pending operation when the close
operation was started, then this function will report %G_IO_ERROR_PENDING, and
return false. If cancellable was not nil, then the operation may have been
cancelled by triggering the cancellable object from another thread. If the operation
was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and false will be
returned.

Parameters:

Returns:

  • (Boolean) —

    true if the close operation has finished successfully.

#container ⇒ Gio::File

Get the #GFile container which is being enumerated.

Returns:

  • (Gio::File) —

    the #GFile which is being enumerated.

#container=(container) ⇒ Gio::File

The container that is being enumerated.

Parameters:

Returns:

#get_child(info) ⇒ Gio::File

Return a new #GFile which refers to the file named by info in the source
directory of enumerator. This function is primarily intended to be used
inside loops with g_file_enumerator_next_file().

To use this, %G_FILE_ATTRIBUTE_STANDARD_NAME must have been listed in the
attributes list used when creating the GFile::Enumerator.

This is a convenience method that's equivalent to:

  gchar *name = g_file_info_get_name (info);
  GFile *child = g_file_get_child (g_file_enumerator_get_container (enumr),
                                   name);

Parameters:

  • info (Gio::FileInfo) —

    a GFile::Info gotten from g_file_enumerator_next_file()
    or the async equivalents.

Returns:

  • (Gio::File) —

    a #GFile for the GFile::Info passed it.

#has_pending ⇒ Boolean

Checks if the file enumerator has pending operations.

Returns:

  • (Boolean) —

    true if the enumerator has pending operations.

#is_closed ⇒ Boolean

Checks if the file enumerator has been closed.

Returns:

  • (Boolean) —

    true if the enumerator is closed.

#iterate(out_info, out_child, cancellable) ⇒ Boolean

This is a version of g_file_enumerator_next_file() that's easier to
use correctly from C programs. With g_file_enumerator_next_file(),
the gboolean return value signifies "end of iteration or error", which
requires allocation of a temporary #GError.

In contrast, with this function, a false return from
g_file_enumerator_iterate() always means
"error". End of iteration is signaled by out_info or out_child being nil.

Another crucial difference is that the references for out_info and
out_child are owned by direnum (they are cached as hidden
properties). You must not unref them in your own code. This makes
memory management significantly easier for C code in combination
with loops.

Finally, this function optionally allows retrieving a #GFile as
well.

You must specify at least one of out_info or out_child.

The code pattern for correctly using g_file_enumerator_iterate() from C
is:

|[
direnum = g_file_enumerate_children (file, ...);
while (TRUE)
{
GFileInfo *info;
if (!g_file_enumerator_iterate (direnum, &info, NULL, cancellable, error))
goto out;
if (!info)
break;
... do stuff with "info"; do not unref it! ...
}

out:
g_object_unref (direnum); // Note: frees the last info
]|

Parameters:

  • out_info (Gio::FileInfo) —

    Output location for the next GFile::Info, or nil

  • out_child (Gio::File) —

    Output location for the next #GFile, or nil

  • cancellable (Gio::Cancellable) —

    a #GCancellable

Returns:

  • (Boolean)

#next_file(cancellable) ⇒ Gio::FileInfo

Returns information for the next file in the enumerated object.
Will block until the information is available. The GFile::Info
returned from this function will contain attributes that match the
attribute string that was passed when the GFile::Enumerator was created.

See the documentation of GFile::Enumerator for information about the
order of returned files.

On error, returns nil and sets error to the error. If the
enumerator is at the end, nil will be returned and error will
be unset.

Parameters:

  • cancellable (Gio::Cancellable) —

    optional #GCancellable object, nil to ignore.

Returns:

  • (Gio::FileInfo) —

    A GFile::Info or nil on error
    or end of enumerator. Free the returned object with
    g_object_unref() when no longer needed.

#next_files_async(num_files, io_priority, cancellable, callback, user_data) ⇒ nil

Request information for a number of files from the enumerator asynchronously.
When all I/O for the operation is finished the callback will be called with
the requested information.

See the documentation of GFile::Enumerator for information about the
order of returned files.

Once the end of the enumerator is reached, or if an error occurs, the
callback will be called with an empty list. In this case, the previous call
to g_file_enumerator_next_files_async() will typically have returned fewer
than num_files items.

If a request is cancelled the callback will be called with
%G_IO_ERROR_CANCELLED.

This leads to the following pseudo-code usage:
|[
g_autoptr(GFile) dir = get_directory ();
g_autoptr(GFileEnumerator) enumerator = NULL;
g_autolist(GFileInfo) files = NULL;
g_autoptr(GError) local_error = NULL;

enumerator = yield g_file_enumerate_children_async (dir,
G_FILE_ATTRIBUTE_STANDARD_NAME ","
G_FILE_ATTRIBUTE_STANDARD_TYPE,
G_FILE_QUERY_INFO_NONE,
G_PRIORITY_DEFAULT,
cancellable,
…,
&local_error);
if (enumerator == NULL)
g_error ("Error enumerating: %s", local_error->message);

// Loop until no files are returned, either because the end of the enumerator
// has been reached, or an error was returned.
do
{
files = yield g_file_enumerator_next_files_async (enumerator,
5, // number of files to request
G_PRIORITY_DEFAULT,
cancellable,
…,
&local_error);

// Process the returned files, but don’t assume that exactly 5 were returned.
for (GList *l = files; l != NULL; l = l->next)
  {
    GFileInfo *info = l->data;
    handle_file_info (info);
  }

}
while (files != NULL);

if (local_error != NULL &&
!g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
g_error ("Error while enumerating: %s", local_error->message);
]|

During an async request no other sync and async calls are allowed, and will
result in %G_IO_ERROR_PENDING errors.

Any outstanding I/O request with higher priority (lower numerical value) will
be executed before an outstanding request with lower priority. Default
priority is %G_PRIORITY_DEFAULT.

Parameters:

  • num_files (Integer) —

    the number of file info objects to request

  • io_priority (Integer) —

    the [I/O priority][io-priority] of the request

  • cancellable (Gio::Cancellable) —

    optional #GCancellable object, nil to ignore.

  • callback (Gio::AsyncReadyCallback) —

    a GAsync::ReadyCallback
    to call when the request is satisfied

  • user_data (GObject) —

    the data to pass to callback function

Returns:

  • (nil)

#next_files_finish(result) ⇒ GLib::List<Gio::FileInfo>

Finishes the asynchronous operation started with g_file_enumerator_next_files_async().

Parameters:

Returns:

  • (GLib::List<Gio::FileInfo>) —

    a #GList of GFile::Infos. You must free the list with
    g_list_free() and unref the infos with g_object_unref() when you're
    done with them.

#pending=(pending) ⇒ nil

Sets the file enumerator as having pending operations.

Parameters:

  • pending (Boolean) —

    a boolean value.

Returns:

  • (nil)