Check bounds for errors and update label accordingly.

def _update_status(self):
        ''' Check bounds for errors and update label accordingly. '''
        label = ''
        # label format, based on time - when slow, go to higher-res display
        delta = time.time() - self.start
        if delta > self.timedelta2:
            self.label_fmt = '%5.2f%%'
        elif delta > self.timedelta1:
            self.label_fmt = '%4.1f%%'

        ratio = self.ratio
        if 0 <= ratio < 1:
            if self.label_mode:
                label = self.label_fmt % (ratio * 100)
            if self.oob_error:  # now fixed, reset
                self._first = self.styles[_if](self.icons[_if])
                self._last = self.styles[_il](self.icons[_il])
                self.oob_error = False
                self._comp_style = self.styles[_ic]
                self.done = False
        else:
            if ratio == 1:
                self.done = True
                self._comp_style = self.styles[_id]
                self._last = self.styles[_if](self.icons[_il])
                if self.label_mode:
                    label = '✓' if self.unicode_support else '+'
                if self.oob_error:  # now fixed, reset
                    self._first = self.styles[_if](self.icons[_if])
                    self.oob_error = False

            elif ratio > 1:
                self.done = True
                self.oob_error = True
                if self.unicode_support:
                    self._last = self._err_style('⏵')
                    if self.label_mode:
                        label = '✗'
                else:
                    self._last = self._err_style('>')
                    if self.label_mode:
                        label = 'ERR'
            else:  # < 0
                self.oob_error = True
                if self.unicode_support:
                    self._first = self._err_style('⏴')
                    if self.label_mode:
                        label = '✗'
                else:
                    self._first = self._err_style('<')
                    if self.label_mode:
                        label = 'ERR'
        self._lbl = label