#!/usr/bin/python
# .+
#
# .identifier : $Id:$
# .context : Application View Controller
# .title : A counter with count speed control (Tk)
# .kind : python source
# .author : Fabrizio Pollastri
# .site : Revello - Italy
# .creation : 17-Nov-2006
# .copyright : (c) 2006 Fabrizio Pollastri
# .license : GNU General Public License (see below)
#
# This file is part of "AVC, Application View Controller".
#
# AVC is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# AVC is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
#
# .-
from Tkinter import * # Tk interface
from avc import * # AVC
TCL_FILE = 'tk_counter.tcl' # GUI description as tcl script
LOW_SPEED = 500 #--
HIGH_SPEED = 100 #- low and high speed count period (ms)
class ExampleGUI:
"Counter GUI creation"
def __init__(self):
# create GUI
self.root = Tk()
self.root.eval('set argc {}; set argv {}; proc ::main {argc argv} {};')
self.root.tk.evalfile(TCL_FILE)
# terminate program at toplevel window destroy: connect toplevel
# destroy signal to termination handler.
self.root.bind_class('Toplevel','',lambda event: self.root.quit())
def timer(self,period,function):
"Start a Tk timer calling back 'function' every 'period' seconds."
self.root.after(period,function)
class ExampleMain(AVC):
"""
A counter displayed in a Label widget whose count speed can be doubled
by pressing a Toggle Button.
"""
def __init__(self,gui):
# save GUI
self.gui = gui
# the counter variable and its speed status
self.counter = 0
self.high_speed = False
# start incrementer timer
self.gui.timer(LOW_SPEED,self.incrementer)
def incrementer(self):
"""
Counter incrementer: increment period = LOW_SPEED, if high speed is False,
increment period = HIGH_SPEED otherwise.
"""
self.counter += 1
if self.high_speed:
period = HIGH_SPEED
else:
period = LOW_SPEED
self.gui.timer(period,self.incrementer)
def high_speed_changed(self,value):
"Notify change of counting speed to terminal"
if value:
print 'counting speed changed to high'
else:
print 'counting speed changed to low'
#### MAIN
example_gui = ExampleGUI() # create the application GUI
example = ExampleMain(example_gui) # instantiate the application
example.avc_init() # connect widgets with variables
mainloop() # run Tk event loop until quit
#### END