code: def configure_widget_for_editing(self, widget):
          
          
          if not 'editor_varname' in widget.attributes:
              return
          widget.onclick.do(self.on_widget_selection)
          
          #setup of the on_dropped function of the widget in order to manage the dragNdrop 
          widget.__class__.on_dropped = on_dropped
  
          #drag properties
          #widget.style['resize'] = 'both'
          widget.style['overflow'] = 'auto'
          widget.attributes['draggable'] = 'true'
                  
          widget.attributes['tabindex']=str(self.tabindex)
          #if not 'position' in widget.style.keys():
          #    widget.style['position'] = 'absolute'
          #if not 'left' in widget.style.keys():
          #    widget.style['left'] = '1px'
          #if not 'top' in widget.style.keys():
          #    widget.style['top'] = '1px'
          self.tabindex += 1
docs: A widget have to be added to the editor, it is configured here in order to be conformant 
              to the editor