def _changeColor(self, param, val):
c = param.opts['curve']
pen = c.opts['pen']
if not isinstance(pen, QtGui.QPen):
pen = QtGui.QPen()
pen.setColor(val)
c.setPen(pen)
def paint(self, p, opt, widget):
pen = QtGui.QPen(self.currentPen)
pen.setWidth(pen.width() // 2)
c = pen.color()
r, g, b, a = c.getRgb()
c.setRgb(255 - r, 255 - g, 255 - b) # invert
pen.setColor(c)
p.setPen(pen)
p.setRenderHint(QtGui.QPainter.Antialiasing)
p.drawPath(self.painterPath())
