def keyPressEvent(self, event):
        """Reimplemented."""
        # Override the default QComboBox behavior
        if event.key() == Qt.Key_Down and event.modifiers() & Qt.AltModifier:
            self.showPopup()
            return

        ignored = {Qt.Key_Up, Qt.Key_Down,
                   Qt.Key_PageDown, Qt.Key_PageUp,
                   Qt.Key_Home, Qt.Key_End}

        if event.key() in ignored:
            event.ignore()
            return

        super(CheckComboBox, self).keyPressEvent(event) 

def test_PythonProcessPane_parse_input_home(qtapp):
    """
    Home moves cursor to the start of the input line.
    """
    ppp = mu.interface.panes.PythonProcessPane()
    ppp.toPlainText = mock.MagicMock(return_value="hello")
    mock_cursor = mock.MagicMock()
    ppp.start_of_current_line = 0
    ppp.textCursor = mock.MagicMock(return_value=mock_cursor)
    ppp.setTextCursor = mock.MagicMock()
    key = Qt.Key_Home
    text = ""
    modifiers = None
    ppp.parse_input(key, text, modifiers)
    # Move to the end of the line, then move left len of 'hello'.
    assert mock_cursor.movePosition.call_count == 6
    ppp.setTextCursor.assert_called_once_with(mock_cursor) 

def top(self):
        self._key_press(Qt.Key_Home) 

def test_MicroPythonREPLPane_keyPressEvent_home(qtapp):
    """
    Ensure home key in the REPL is handled correctly.
    """
    mock_serial = mock.MagicMock()
    rp = mu.interface.panes.MicroPythonREPLPane(mock_serial)
    data = mock.MagicMock
    data.key = mock.MagicMock(return_value=Qt.Key_Home)
    data.text = mock.MagicMock(return_value="1b")
    data.modifiers = mock.MagicMock(return_value=None)
    rp.keyPressEvent(data)
    mock_serial.write.assert_called_once_with(b"\x1B[H")