code: def highlight_event(self, annot):
          
          beg = annot.marker.x()
          end = beg + annot.marker.width()
          window_start = self.parent.value('window_start')
          window_length = self.parent.value('window_length')
          events = self.parent.notes.get_selected_events((window_start, 
                                                  window_start + window_length))
          ev = [x for x in events if (x['start'] == annot.marker.x() or \
                                      x['end'] == annot.marker.y())]
          
          if ev:
              annot_name = ev[0]['name']
              
              msg = "Event of type '{}' from {} to {}".format(
                      annot_name, beg, end)
              self.current_etype = self.parent.notes.idx_eventtype.currentText()
              self.parent.notes.idx_eventtype.setCurrentText(annot_name)
              self.current_event = ev[0]
          else:
              msg = "Marker from {} to {}".format(beg, end)
          self.parent.statusBar().showMessage(msg)
              
          highlight = self.highlight = RectMarker(annot.marker.x(),
                                                 annot.marker.y(),
                                                 annot.marker.width(),
                                                 annot.marker.height(),
                                                 zvalue=-5,
                                                 color=QColor(255, 255, 51))
          self.scene.addItem(highlight)
          self.event_sel = annot
docs: Highlight an annotation on the trace.
          
          Parameters
          ----------
          annot : intance of wonambi.widgets.utils.RectMarker
              existing annotation