'Refresh widget
force=False: won\'t refresh widget if path has not changed'

def refresh(self, new_path=None, force_current=False):

    if (new_path is None):
        new_path = getcwd()
    if force_current:
        index = self.set_current_folder(new_path)
        self.expand(index)
        self.setCurrentIndex(index)
    self.set_previous_enabled.emit(((self.histindex is not None) and (self.histindex > 0)))
    self.set_next_enabled.emit(((self.histindex is not None) and (self.histindex < (len(self.history) - 1))))
    self.filter_directories()
