value_change.py

def valuechange(self):
        # We access our global variables within the function
        global framesTaken
        global framesSpecified

        # We set the framesSpecified value to
        # whatever is specified on the spinbox
        framesSpecified = self.sp.value()

        # We modify our label to give us info, how many
        # frames have been captured so far
        self.l2.setText(
            "Frames taken: "+str(framesTaken)+" from "+str(framesSpecified))

        # Once the snapshot taking process has begun,
        # we need to disable the spinbox
        self.sp.setEnabled(0) if (framesTaken > 0) else self.sp.setEnabled(1)

        # We enable our snapshot trigger button, if frames have been specified
        # and the process is ongoing.
        # If the process ends, we disable the button again
        if (self.sp.value() > 0
            and framesTaken < 10
                and framesTaken < framesSpecified):
            self.snapbutton.setEnabled(1)
        else:
            self.snapbutton.setEnabled(0)

        if (self.sp.value() > 0):
            self.l2.setVisible(1)
        else:
            self.l2.setVisible(0)