code: def limit_dragpos(self):
          '''limit dragpos to sane values'''
          if self.dragpos.x < 0:
              self.dragpos.x = 0
          if self.dragpos.y < 0:
              self.dragpos.y = 0
          if self.img is None:
              return
          if self.dragpos.x >= self.img.GetWidth():
              self.dragpos.x = self.img.GetWidth()-1
          if self.dragpos.y >= self.img.GetHeight():
              self.dragpos.y = self.img.GetHeight()-f limit_dragpos(self):
          '''limit dragpos to sane values'''
          if self.dragpos.x < 0:
              self.dragpos.x = 0
          if self.dragpos.y < 0:
              self.dragpos.y = 0
          if self.img is None:
              return
          if self.dragpos.x >= self.img.GetWidth():
              self.dragpos.x = self.img.GetWidth()-1
          if self.dragpos.y >= self.img.GetHeight():
              self.dragpos.y = self.img.GetHeight()-1
docs: limit dragpos to sane values