'After an application style change, the paintEvent updates the
custom defined stylesheet.'

def _refresh(self):

    padding = self.height()
    css_base = 'QLineEdit    {{\n                                                                                                                                    border:    none;\n                                                                                                                                    padding-right:    {padding}px;\n                                                                                                                                    }}\n                                                                            '
    css_oxygen = 'QLineEdit    {{background:    transparent;\n                                                                                                                                            border:    none;\n                                                                                                                                            padding-right:    {padding}px;\n                                                                                                                                            }}\n                                                                                    '
    if (self._application_style == 'oxygen'):
        css_template = css_oxygen
    else:
        css_template = css_base
    css = css_template.format(padding=padding)
    self.setStyleSheet(css)
    self.update()
