code: def resizeEvent(self, event):
          
          vp = self.viewport()
          rect = vp.geometry()
          x1, y1, x2, y2 = rect.getCoords()
          width = x2 - x1 + 1
          height = y2 - y1 + 1
  
          self.v_w.resize(width, height)
docs: Override from QAbstractScrollArea.
          Resize the viewer widget when the viewport is resized.