class_docstr: Overlay widget that draws drop areas during a drag-drop operation
code: def setDropArea(self, area):
      self.dropArea = area
      if area is None:
          self.hide()
      else:
          ## Resize overlay to just the region where drop area should be displayed.
          ## This works around a Qt bug--can't display transparent widgets over QGLWidget
          prgn = self.parent().rect()
          rgn = QtCore.QRect(prgn)
          w = min(30, int(prgn.width() / 3))
          h = min(30, int(prgn.height() / 3))
  
          if self.dropArea == "left":
              rgn.setWidth(w)
          elif self.dropArea == "right":
              rgn.setLeft(rgn.left() + prgn.width() - w)
          elif self.dropArea == "top":
              rgn.setHeight(h)
          elif self.dropArea == "bottom":
              rgn.setTop(rgn.top() + prgn.height() - h)
          elif self.dropArea == "center":
              rgn.adjust(w, h, -w, -h)
          self.setGeometry(rgn)
          self.show()
  
      self.update()
  
file_path: pyqtgraph/pyqtgraph/dockarea/DockDrop.py
imports: from ..Qt import QtCore, QtGui, QtWidgets
label_desc: Use image node_id 2 for calling the DropAreaOverlay obj's underlying member method code with example usage: obj.setDropArea(area) without return types