docs: def reset( self ):
          """
          Resets the user interface buttons for this widget.
          """
          # clear previous widgets
          for btn in self.findChildren(QToolButton):
              btn.close()
              btn.setParent(None)
              btn.deleteLater()
          
          # determine coloring options
          palette             = self.palette()
          unchecked           = palette.color(palette.Button)
          
          # determine if this is a dark or light scheme
          avg = (unchecked.red() + unchecked.green() + unchecked.blue()) / 3.0
          if ( avg < 140 ):
              checked             = unchecked.lighter(115)
              
              checked_clr         = self.colorString(unchecked.lighter(120))
              border_clr          = self.colorString(unchecked.darker(140))
              unchecked_clr       = self.colorString(checked.lighter(140))
              unchecked_clr_alt   = self.colorString(checked.lighter(120))
              checked_clr_alt     = self.colorString(unchecked)
          else:
              checked             = unchecked.lighter(120)
              
              checked_clr         = self.colorString(unchecked)
              border_clr          = self.colorString(unchecked.darker(160))
              unchecked_clr       = self.colorString(checked)
              unchecked_clr_alt   = self.colorString(checked.darker(130))
              checked_clr_alt     = self.colorString(unchecked.darker(120))
          
          # define the stylesheet options
          options = {}
          options['top_left_radius']      = 0
          options['top_right_radius']     = 0
          options['bot_left_radius']      = 0
          options['bot_right_radius']     = 0
          options['border_color']         = border_clr
          options['checked_clr']          = checked_clr
          options['checked_clr_alt']      = checked_clr_alt
          options['unchecked_clr']        = unchecked_clr
          options['unchecked_clr_alt']    = unchecked_clr_alt
          options['padding_top']          = 1
          options['padding_bottom']       = 1
          options['padding_left']         = 1
          options['padding_right']        = 1
          
          horiz = self.direction() in (QBoxLayout.LeftToRight, 
                                       QBoxLayout.RightToLeft)
          
          if ( horiz ):
              options['x1'] = 0
              options['y1'] = 0
              options['x2'] = 0
              options['y2'] = 1
          else:
              options['x1'] = 0
              options['y1'] = 0
              options['x2'] = 1
              options['y2'] = 1
          
          actions = self.actionGroup().actions()
          count = len(actions)
          for i, action in enumerate(actions):
              btn = QToolButton(self)
              btn.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Preferred)
              btn.setDefaultAction(action)
              self.layout().insertWidget(i, btn)
              
              options['top_left_radius']  = 1
              options['bot_left_radius']  = 1
              options['top_right_radius'] = 1
              options['bot_right_radius'] = 1
              
              if ( horiz ):
                  options['padding_left']     = self._padding
                  options['padding_right']    = self._padding
              else:
                  options['padding_top']      = self._padding
                  options['padding_bottom']   = self._padding
              
              if ( not i ):
                  if ( horiz ):
                      options['top_left_radius'] = self.cornerRadius()
                      options['bot_left_radius'] = self.cornerRadius()
                      options['padding_left']    += self.cornerRadius() / 3.0
                  else:
                      options['top_left_radius'] = self.cornerRadius()
                      options['top_right_radius'] = self.cornerRadius()
                      options['padding_top']     += self.cornerRadius() / 3.0
                      
              elif ( i == count - 1 ):
                  if ( horiz ):
                      options['top_right_radius'] = self.cornerRadius()
                      options['bot_right_radius'] = self.cornerRadius()
                      options['padding_right']    += self.cornerRadius() / 3.0
                  else:
                      options['bot_left_radius']  = self.cornerRadius()
                      options['bot_right_radius'] = self.cornerRadius()
                      options['padding_bottom']   += self.cornerRadius() / 3.0
              
              btn.setStyleSheet(TOOLBUTTON_STYLE % options)
              btn.setAutoFillBackground(True)