See GTK+/GtkFileChooserInternals

GtkFilePath is a GtkFileSystem-implementation-dependent file path. It is private API.

GtkFilePath functions take a GtkFileSystem* parameter because they are implemented as vfuncs on a GtkFileSystem, such as GtkFileSystem::path_to_uri() and GtkFileSystem::uri_to_path().

• Use gtk_file_system_uri_to_path()to get a GtkFilePath* from a URI string (such as file:///home/users/something.txt).

• Use gtk_file_path_free() to free the resulting GtkFilePath.

• Use gtk_file_system_path_to_uri() to get a URI string from a GtkFilePath*.