code: def mousePressEvent(self, ev):
      pos = ev.scenePos()
      if not self.creating and not self.hovering:
          if ev.buttons() in [Qt.LeftButton, Qt.RightButton]:
              x, y = int(pos.x()), int(pos.y())
              self.clickRequest.emit(
                  x, y, ev.buttons() == Qt.LeftButton
              )
              if self.is_draw:
                  self.rect_box = [x, y, x, y]
                  self.rectboxReques.emit(
                      *self.rect_box
                  )  # 添加一个空矩形用于被删除
                  self.is_press = True
      elif self.hovering:
          for poly in self.polygon_items:
              if poly.polygon_hovering:
                  self.focusRequest.emit(poly.labelIndex)
      super(AnnotationScene, self).mousePressEvent(ev)
  
imports: from qtpy import QtWidgets, QtCore
  from qtpy.QtCore import Qt, QPointF
  from qtpy.QtGui import QPen, QColor
label_desc: Use image node_id 7 for calling the AnnotationScene obj's underlying member method code with example usage: obj.mousePressEvent(ev) without return types