# -*- coding: utf-8 -*-
# Python 2 & 3

from __future__ import print_function # Replace print function

import time
import threading
import locale
import sys

try: # { v2
	import Tkinter as tkinter
	import ttk # Tk themed widgets
	print = lambda text: sys.stdout.write(text.decode('utf-8', errors='replace').encode(
		locale.getlocale()[1],
		errors='replace'
	) + '\n')
except: # v3
	import tkinter
	from tkinter import ttk # Tk themed widgets
# }

class Application(object): # {
	def __init__(self, init_root): # {
		self.root = init_root

		self.label_var = tkinter.StringVar()
		ttk.Label(self.root, textvariable=self.label_var).pack()
		self.label_var.set("Press any key, Enter, Escape")

		self.button_exit = ttk.Button(self.root, command=self.callback_exit, text="Exit")
		self.button_exit.pack()

		self.root.bind('<Escape>', self.callback_bind_escape) # Escape key
		self.root.bind('<Key>', self.callback_bind_key) # any key
		self.root.bind('<Return>', self.callback_bind_return) # Enter key

		self.root.update()
		#self.button_exit.focus() # Select as default/selected button
	# }
	def callback_bind_escape(self, event=None, *args): # {
		self.button_exit.invoke() # Execute button
	# }
	def callback_bind_key(self, event=None, *args): # {
		if event: # {
			print(event.char)
			if len(event.char): # printable
				self.label_var.set(repr(event.char)) # Encoding for special characters is required
		# }
	# }
	def callback_bind_return(self, event=None, *args): # {
		if event.widget is self.button_exit: # { If button_exit focused/selected
			self.button_exit.invoke() # Execute button
		else:
			print("Focus on Exit button to Exit, with tab")
			self.label_var.set("Focus on Exit button to Exit, with tab")
		# }
	# }
	def callback_exit(self): # {
		self.root.destroy()
		print("Exit")
		self.label_var.set("Exit")
	# }
# } class

if __name__ == "__main__": # {
	root = tkinter.Tk()
	application = Application(root)
	root.mainloop() # Blocking until destroy()
	print("Done")
# }