code: def mousePressEvent(self, ev):
      if ev.button() == QtCore.Qt.MouseButton.LeftButton:
          ev.accept()
          self.pressDelta = self.mapToParent(ev.pos()) - self.pos()
      else:
          ev.ignore()
  
file_path: pyqtgraph/pyqtgraph/examples/ViewBox.py
imports: import numpy
  import pyqtgraph
  from pyqtgraph.Qt import QtCore, QtWidgets
label_desc: Use image node_id 4 for calling the movableRect obj's underlying member method code with example usage: obj.mousePressEvent(ev) without return types