# This script aniamtes "Box" attached to an curve with MapPathParameter

FreeCAD attachment animation

# This script aniamtes "Box" attached to an curve with MapPathParameter
import FreeCAD as App, FreeCADGui as Gui, Part, time
from PySide2 import QtGui,QtCore

class Animation(object):
    def __init__(self):
        App.Console.PrintMessage('Animation has started\n')
        App.ActiveDocument.recompute()

        self.timer = QtCore.QTimer()
        QtCore.QObject.connect(self.timer, QtCore.SIGNAL("timeout()"), self.my_update)
        self.timer.start(100) #step every 0.1s (100 ms)
        self.val = 0.0 #start
        self.step = 0.01 #step value
        self.end = 1.0 #end value

    def my_update(self):
        App.ActiveDocument.getObject('Box').MapPathParameter = self.val #move the box on the path
        self.val = self.val + self.step #
        App.ActiveDocument.recompute()
        if self.val > self.end:
            # self.timer.stop() #uncomment to stop animation after reaching end value
            self.val = 0.0

    def stop(self):
        self.timer.stop()
        App.Console.PrintMessage('Animation stopped\n')

animation = Animation()

#to stop type animation.stop()