class_docstr: Overlay widget that draws drop areas during a drag-drop operation
code: def paintEvent(self, ev):
      if self.dropArea is None:
          return
      p = QtGui.QPainter(self)
      rgn = self.rect()
  
      p.setBrush(QtGui.QBrush(QtGui.QColor(100, 100, 255, 50)))
      p.setPen(QtGui.QPen(QtGui.QColor(50, 50, 150), 3))
      p.drawRect(rgn)
      p.end()
  
file_path: pyqtgraph/pyqtgraph/dockarea/DockDrop.py
imports: from ..Qt import QtCore, QtGui, QtWidgets
label_desc: Use image node_id 3 for calling the DropAreaOverlay obj's underlying member method code with example usage: obj.paintEvent(ev) without return types