This signal is emitted when the current folder in a FileChooser changes.
This can happen due to the user performing some action that changes folders, such as selecting a bookmark or visiting a folder on the file list. It can also happen as a result of calling a function to explicitly change the current folder in a file chooser.
Normally you do not need to connect to this signal, unless you need to keep track of which folder a file chooser is showing.
See also: set_current_folder, get_current_folder, set_current_folder_uri, get_current_folder_uri.