def _on_action_visible_changed(self, action, trait_name, old, new):

        self.tool_bar.EnableTool(self.control_id, action.visible and action.enabled)

        return
C{readline()} should mirror L{file.readline} and return up to a single
dataset/ETHPy150Open enthought/pyface/pyface/ui/wx/action/action_item.py/_Tool._on_action_visible_changed--crossover with--dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/python/test/test_zipstream.py/FileEntryMixin.test_readline