Method test_mousewheel

Lib/idlelib/idle_test/test_sidebar.py:681–710

(self)

    @run_in_tk_mainloop()
    def test_mousewheel(self):
        sidebar = self.shell.shell_sidebar
        text = self.shell.text

        # Enter a 100-line string to scroll the shell screen down.
        self.do_input('x = """' + '\n'*100 + '"""\n')
        yield
        self.assertGreater(get_lineno(text, '@0,0'), 1)

        last_lineno = get_end_linenumber(text)
        self.assertIsNotNone(text.dlineinfo(text.index(f'{last_lineno}.0')))

        # Delta for <MouseWheel>, whose meaning is platform-dependent.
        delta = 1 if sidebar.canvas._windowingsystem == 'aqua' else 120

        # Scroll up.
        if sidebar.canvas._windowingsystem == 'x11':
            sidebar.canvas.event_generate('<Button-4>', x=0, y=0)
        else:
            sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=delta)
        yield
        self.assertIsNone(text.dlineinfo(text.index(f'{last_lineno}.0')))

        # Scroll back down.
        if sidebar.canvas._windowingsystem == 'x11':
            sidebar.canvas.event_generate('<Button-5>', x=0, y=0)
        else:
            sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=-delta)
        yield
        self.assertIsNotNone(text.dlineinfo(text.index(f'{last_lineno}.0')))

    @run_in_tk_mainloop()
    def test_copy(self):