docs: def _checkDragDropEvent(self, ev):
          """Checks if event contains a file URL, accepts if it does, ignores if it doesn't"""
          mimedata = ev.mimeData()
          if mimedata.hasUrls():
              urls = [str(url.toLocalFile()) for url in mimedata.urls() if url.toLocalFile()]
          else:
              urls = []
          # accept event if drag text is a file URL
          if urls:
              ev.acceptProposedAction()
              return urls
          else:
              ev.ignore()
              return None