###################################################################
# use threads to move objects; seems to work on Windows provided 
# that canvas.update() not called by threads(else exits with fatal
# errors, some objs start moving immediately after drawn, etc.);
# at least some canvas method calls must be thread safe in Tkinter;
# this is less smooth than time.sleep, and is dangerous in general:
# threads are best coded to update global vars, not change GUI;
###################################################################

import thread, time, sys, random
from Tkinter import Tk, mainloop
from movingpics import MovingPics, pickUnits, pickDelays

class MovingPicsThreaded(MovingPics):
    def __init__(self, parent=None):
        MovingPics.__init__(self, parent)
        self.mutex = thread.allocate_lock()
        import sys
        #sys.setcheckinterval(0) # switch after each vm op- doesn't help
    def onMove(self, event):
        object = self.object
        if object and object not in self.moving: 
            msecs  = int(pickDelays[0] * 1000)
            parms  = 'Delay=%d msec, Units=%d' % (msecs, pickUnits[0])
            self.setTextInfo(parms)
            #self.mutex.acquire()
            self.moving.append(object) 
            #self.mutex.release()
            thread.start_new_thread(self.doMove, (object, event))
    def doMove(self, object, event):
        canvas = event.widget
        incrX, reptX, incrY, reptY = self.plotMoves(event)
        for i in range(reptX):
            canvas.move(object, incrX, 0) 
            # canvas.update()
            time.sleep(pickDelays[0])         # this can change
        for i in range(reptY):
            canvas.move(object, 0, incrY)
            # canvas.update()                 # update runs other ops
            time.sleep(pickDelays[0])         # sleep until next move
        #self.mutex.acquire()
        self.moving.remove(object)
        if self.object == object: self.where  = event
        #self.mutex.release()
        
if __name__ == '__main__':
    root = Tk()
    MovingPicsThreaded(root)
    mainloop()