def triggered(self, action):
        if action == QAbstractSlider.SliderSingleStepAdd:
            self.whex.view.move(self.singleStep(), 1)
        elif action == QAbstractSlider.SliderSingleStepSub:
            self.whex.view.move(self.singleStep(), 0)
        elif action == QAbstractSlider.SliderPageStepSub:
            self.whex.view.move(self.pageStep(), 0)
        elif action == QAbstractSlider.SliderPageStepAdd:
            self.whex.view.move(self.pageStep(), 1)