#! /usr/bin/python3

from tkinter import *
import time

########################################################################
#                        CLASS Chrono
########################################################################

class Chrono(Frame):                                                               
    def __init__(self, parent=None, **kw):        
        Frame.__init__(self, parent, kw)
        self._start = 0.0        
        self._elapsedtime = 0.0
        self._running = 0
        self.timestr = StringVar()               
        self.makeWidgets()      

    def makeWidgets(self): # Make the time label
        l = Label(self, textvariable=self.timestr)
        self._setTime(self._elapsedtime)
        l.pack(fill=X, expand=NO, pady=2, padx=2)                      
    
    def _update(self): # Update the label with elapsed time
        self._elapsedtime = time.time() - self._start
        self._setTime(self._elapsedtime)
        self._timer = self.after(50, self._update)
    
    def _setTime(self, elap): # Minutes:Seconds:Hundreths
        minutes = int(elap/60)
        seconds = int(elap - minutes*60.0)
        hseconds = int((elap - minutes*60.0 - seconds)*100)                
        self.timestr.set('%02d:%02d:%02d' % (minutes, seconds, hseconds))
        
    def Start(self): # Start the stopwatch, ignore if running                                           
        if not self._running:            
            self._start = time.time() - self._elapsedtime
            self._update()
            self._running = 1        
    
    def Stop(self):                                    
        if self._running:
            self.after_cancel(self._timer)            
            self._elapsedtime = time.time() - self._start    
            self._setTime(self._elapsedtime)
            self._running = 0
    
    def Reset(self):                                  
        self._start = time.time()         
        self._elapsedtime = 0.0    
        self._setTime(self._elapsedtime)

########################################################################
#                        MAIN
########################################################################     
        
if  __name__ == "__main__" :
	
    ui = Tk()    
    ui.title("Timer")
    
    chron = Chrono(ui)
    chron.pack(side=TOP)
    
    Button(ui, text='Start', command=chron.Start).pack(side=LEFT)
    Button(ui, text='Stop', command=chron.Stop).pack(side=LEFT)
    Button(ui, text='Reset', command=chron.Reset).pack(side=LEFT)
    Button(ui, text='Quit', command=ui.quit).pack(side=LEFT)
    
    ui.mainloop()

########################################################################