code: def _on_mouse_moved(self, event):
          
          if event.modifiers() & Qt.ControlModifier:
              self._select_word_under_mouse_cursor()
          else:
              self._remove_decoration()
              self.editor.set_mouse_cursor(Qt.IBeamCursor)
              self._previous_cursor_start = -1
              self._previous_cursor_end = -1
docs: mouse moved callback