state = fields.Selection([
        ('draft', 'New'),
        ('pending', 'To Renew'),
        ('close', 'Expired'),
    ], string='Status', default='draft')


    @api.multi
    def set_as_pending(self):
        return self.write({'state': 'pending'})

    @api.multi
    def set_as_close(self):
        return self.write({'state': 'close'})

<field name="state" widget="statusbar" clickable="1" />