Smart HOME feature: cursor is first moved at
        indentation position, then at the start of the line

def stdkey_home(self, shift, ctrl, prompt_pos=None):
        """Smart HOME feature: cursor is first moved at
        indentation position, then at the start of the line"""
        move_mode = self.__get_move_mode(shift)
        if ctrl:
            self.moveCursor(QTextCursor.Start, move_mode)
        else:
            cursor = self.textCursor()
            if prompt_pos is None:
                start_position = self.get_position('sol')
            else:
                start_position = self.get_position(prompt_pos)
            text = self.get_text(start_position, 'eol')
            indent_pos = start_position+len(text)-len(text.lstrip())
            if cursor.position() != indent_pos:
                cursor.setPosition(indent_pos, move_mode)
            else:
                cursor.setPosition(start_position, move_mode)
            self.setTextCursor(cursor)