def _select_other_window(history):
    """ Toggle focus between left/right window. """
    current_buffer = history.app.current_buffer
    layout = history.history_layout.layout
    if current_buffer == history.history_buffer:
        layout.current_control = history.history_layout.default_buffer_control
    elif current_buffer == history.default_buffer:
        layout.current_control = history.history_layout.history_buffer_control
