The File class inherits QWidget Qt class.
Widget's input value
A filesystem path.
Widget's attributes
Widget's output value
A dict in the form {'uri':URI, 'data':DATA}.
If mode is file, URI is the path of the file and DATA is a base64 representation of the file's content.
If mode is files, URI is a list of files paths and DATA is a list of base64 representations is the same order as URI.
If mode is dir, URI is the path of the directory and DATA is a base64 representation of a tar file of the directory.
If mode is save, URI is the path of the selected file and DATA is None.
If verbose is False, DATA is always None.