code: def on_treeview_delete_selection(self, event=None):
          
  
          tv = self.treeview
          selection = tv.selection()
  
          # Need to remove filter
          self.filter_remove(remember=True)
  
          toplevel_items = tv.get_children()
          parents_to_redraw = set()
          for item in selection:
              try:
                  parent = ''
                  if item not in toplevel_items:
                      parent = self.get_toplevel_parent(item)
                  else:
                      self.previewer.delete(item)
                  del self.treedata[item]
                  tv.delete(item)
                  self.app.set_changed()
                  if parent:
                      self._update_max_grid_rc(parent)
                      parents_to_redraw.add(parent)
                  self.widget_editor.hide_all()
              except tk.TclError:
                  # Selection of parent and child items ??
                  # TODO: notify something here
                  pass
          # redraw widgets
          for item in parents_to_redraw:
              self.draw_widget(item)
          # restore filter
          self.filter_restore()
docs: Removes selected items from treeview