This signal is emitted when there is a change in the set of selected files in a FileChooser.
This can happen when the user modifies the selection with the mouse or the keyboard, or when explicitly calling functions to change the selection.
Normally you do not need to connect to this signal, as it is easier to wait for the file chooser to finish running, and then to get the list of selected files using the functions mentioned below.
See also: select_filename, unselect_filename, get_filename, get_filenames, select_uri, unselect_uri, get_uri , get_uris.