This signal is emitted when the current folder in a GtkFileChooser 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: gtk_file_chooser_set_current_folder(), gtk_file_chooser_get_current_folder(), gtk_file_chooser_set_current_folder_uri(), gtk_file_chooser_get_current_folder_uri().