"""
Copyright (c) 2018, congatec AG. All rights reserved.

This program is free software; you can redistribute it and/or
modify it under the terms of the BSD 2-clause license which 
accompanies this distribution. 

This program 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 BSD 2-clause license for more details.

The full text of the license may be found at:        
http://opensource.org/licenses/BSD-2-Clause   

--------------------------------------------------------------

Rev 1.0   09-09-2016	LKA		Initial release.

"""

class _Getch:
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()

class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()

getch = _Getch()