nopenpilot/tools/lib/kbhit.py

82 lines
1.8 KiB
Python

#!/usr/bin/env python
import sys
import termios
import atexit
from select import select
STDIN_FD = sys.stdin.fileno()
class KBHit:
def __init__(self) -> None:
''' Creates a KBHit object that you can call to do various keyboard things.
'''
self.set_kbhit_terminal()
def set_kbhit_terminal(self) -> None:
''' Save old terminal settings for closure, remove ICANON & ECHO flags.
'''
# Save the terminal settings
self.old_term = termios.tcgetattr(STDIN_FD)
self.new_term = self.old_term.copy()
# New terminal setting unbuffered
self.new_term[3] &= ~(termios.ICANON | termios.ECHO) # type: ignore
termios.tcsetattr(STDIN_FD, termios.TCSAFLUSH, self.new_term)
# Support normal-terminal reset at exit
atexit.register(self.set_normal_term)
def set_normal_term(self) -> None:
''' Resets to normal terminal. On Windows this is a no-op.
'''
termios.tcsetattr(STDIN_FD, termios.TCSAFLUSH, self.old_term)
@staticmethod
def getch() -> str:
''' Returns a keyboard character after kbhit() has been called.
Should not be called in the same program as getarrow().
'''
return sys.stdin.read(1)
@staticmethod
def getarrow() -> int:
''' Returns an arrow-key code after kbhit() has been called. Codes are
0 : up
1 : right
2 : down
3 : left
Should not be called in the same program as getch().
'''
c = sys.stdin.read(3)[2]
vals = [65, 67, 66, 68]
return vals.index(ord(c))
@staticmethod
def kbhit():
''' Returns True if keyboard character was hit, False otherwise.
'''
return select([sys.stdin], [], [], 0)[0] != []
# Test
if __name__ == "__main__":
kb = KBHit()
print('Hit any key, or ESC to exit')
while True:
if kb.kbhit():
c = kb.getch()
if c == '\x1b': # ESC
break
print(c)
kb.set_normal_term()