    def test_disabled_text(self):
        """
        Check disabled TextBox can be used for pre-formatted output.
        """
        # Create a dummy screen.
        screen = MagicMock(spec=Screen, colours=8, unicode_aware=False)
        scene = Scene([], -1)
        canvas = Canvas(screen, 10, 40, 0, 0)

        # Create the form we want to test.
        form = Frame(canvas, canvas.height, canvas.width, has_border=False, can_scroll=False)
        layout = Layout([100], fill_frame=True)
        form.add_layout(layout)
        text_box = TextBox(1, as_string=True)
        text_box.disabled = True
        layout.add_widget(text_box)
        form.fix()
        scene.add_effect(form)
        form.reset()

        # Check that input has no effect on the programmed value.
        text_box.value = "A test"
        self.process_keys(form, ["A"])
        form.save()
        self.assertEqual(text_box.value, "A test")

        # Check that we can provide a custom colour.  Since the default palette has no "custom"
        # key, this will throw an exception.
        self.assertEqual(text_box._pick_colours("blah"), form.palette["disabled"])
        with self.assertRaises(KeyError) as cm:
            text_box.custom_colour = "custom"
            text_box._pick_colours("blah")
        self.assertIn("custom", str(cm.exception))

        # Also check the value is returned as set
        self.assertEqual(text_box.custom_colour, "custom")
Check disabled TextBox can be used for pre-formatted output.
tests/test_widgets.py