'test LineEdit'

def test_lineedit(self):

    line = LineEdit()
    line.show()
    action1 = QAction(QIcon(line.style().standardPixmap(QStyle.SP_ArrowBack)), 'Search', line)
    menu = QMenu()
    menu.addAction('Regex')
    menu.addAction('Wildcard')
    action1.setMenu(menu)
    line.setAction(action1, LineEdit.LeftPosition)
    self.assertIs(line.actionAt(LineEdit.LeftPosition), action1)
    self.assertTrue((line.button(LineEdit.LeftPosition) is not None))
    self.assertTrue((line.button(LineEdit.RightPosition) is None))
    with self.assertRaises(ValueError):
        line.removeActionAt(100)
    line.removeActionAt(LineEdit.LeftPosition)
    self.assertIs(line.actionAt(LineEdit.LeftPosition), None)
    line.setAction(action1, LineEdit.LeftPosition)
    action2 = QAction(QIcon(line.style().standardPixmap(QStyle.SP_TitleBarCloseButton)), 'Delete', line)
    line.setAction(action2, LineEdit.RightPosition)
    line.setPlaceholderText('Search')
    self.assertEqual(line.placeholderText(), 'Search')
    b = line.button(LineEdit.RightPosition)
    b.setFlat(False)
    self.app.exec_()
