code: def refresh(self):
          
          font = self.current_font
  
          # refresh btn_bold
          self.btn_bold.blockSignals(True)
          self.btn_bold.setChecked(font.weight() > 50)
          self.btn_bold.blockSignals(False)
  
          # refresh btn_italic
          self.btn_italic.blockSignals(True)
          self.btn_italic.setChecked(font.italic())
          self.btn_italic.blockSignals(False)
  
          # refresh font size
          self.spin_box.blockSignals(True)
          self.spin_box.setValue(font.pointSize())
          self.spin_box.blockSignals(False)
docs: Refresh the widgets from the current font