#!/usr/bin/env python3 # Copyright 2010-2011 Florent Le Coz <louiz@louiz.org> # # This file is part of Poezio. # # Poezio is free software: you can redistribute it and/or modify # it under the terms of the zlib license. See the COPYING file. """ Functions to interact with the keyboard Mainly, read keys entered and return a string (most of the time ONE char, but may be longer if it's a keyboard shortcut, like ^A, M-a or KEY_RESIZE) """ import curses import curses.ascii import logging log = logging.getLogger(__name__) def get_next_byte(s): """ Read the next byte of the utf-8 char ncurses seems to return a string of the byte encoded in latin-1. So what we get is NOT what we typed unless we do the conversion… """ try: c = s.getkey() except: return (None, None) if len(c) >= 4: return (None, c) return (ord(c), c.encode('latin-1')) # returns a number and a bytes object def get_char_list_old(s): """ Kept for compatibility for python versions without get_wchar() (introduced in 3.3) Read one or more bytes, concatenate them to create a unicode char. Also treat special bytes to create special chars (like control, alt, etc), returns one or more utf-8 chars see http://en.wikipedia.org/wiki/UTF-8#Description """ ret_list = [] # The list of all chars. For example if you paste a text, the list the chars pasted # so that they can be handled at once. (first, char) = get_next_byte(s) while first is not None or char is not None: if not isinstance(first, int): # Keyboard special, like KEY_HOME etc return [char] if first == 127 or first == 8: ret_list.append("KEY_BACKSPACE") break s.timeout(0) # we are now getting the missing utf-8 bytes to get a whole char if first < 127: # ASCII char on one byte if first <= 26: # transform Ctrl+* keys char = chr(first + 64) ret_list.append("^"+char) (first, char) = get_next_byte(s) continue if first == 27: second = get_char_list_old(s) if not second: # if escape was pressed, a second char # has to be read. But it timed out. return [] res = 'M-%s' % (second[0],) ret_list.append(res) (first, char) = get_next_byte(s) continue if 194 <= first: (code, c) = get_next_byte(s) # 2 bytes char char += c if 224 <= first: (code, c) = get_next_byte(s) # 3 bytes char char += c if 240 <= first: (code, c) = get_next_byte(s) # 4 bytes char char += c try: ret_list.append(char.decode('utf-8')) # return all the concatened byte objets, decoded except UnicodeDecodeError: return None # s.timeout(1) # timeout to detect a paste of many chars (first, char) = get_next_byte(s) return ret_list def get_char_list_new(s): ret_list = [] while True: try: key = s.get_wch() except curses.error: # No input, this means a timeout occurs. return ret_list except ValueError: # invalid input log.debug('Invalid character entered.') return ret_list s.timeout(0) if isinstance(key, int): ret_list.append(curses.keyname(key).decode()) else: if curses.ascii.isctrl(key): key = curses.unctrl(key).decode() # Here special cases for alt keys, where we get a ^[ and then a second char if key == '^[': try: part = s.get_wch() except curses.error: pass except ValueError: # invalid input log.debug('Invalid character entered.') else: key = 'M-%s' % part # and an even more special case for keys like # ctrl+arrows, where we get ^[, then [, then a third # char. if key == 'M-[': try: part = s.get_wch() except curses.error: pass except ValueError: log.debug('Invalid character entered.') else: key = '%s-%s' % (key, part) if key == '\x7f' or key == '\x08': key = '^?' elif key == '\r': key = '^M' ret_list.append(key) class Keyboard(object): def __init__(self): self.get_char_list = get_char_list_new self.escape = False def escape_next_key(self): """ The next key pressed by the user should be escaped. e.g. if the user presses ^N, keyboard.get_user_input() will return ["^", "N"] instead of ["^N"]. This will display ^N in the input, instead of interpreting the key binding. """ self.escape = True def get_user_input(self, s, timeout=1000): """ Returns a list of all the available characters to read (for example it may contain a whole text if there’s some lag, or the user pasted text, or the user types really really fast). Also it can return None, meaning that it’s time to do some other checks (because this function is blocking, we need to get out of it every now and then even if nothing was entered). """ s.timeout(timeout) # The timeout for timed events to be checked every second try: ret_list = self.get_char_list(s) except AttributeError: # caught if screen.get_wch() does not exist. In that case we use the # old version, so this exception is caught only once. No efficiency # issue here. log.debug("get_wch() missing, switching to old keyboard method") self.get_char_list = get_char_list_old ret_list = self.get_char_list(s) if not ret_list: # nothing at all was read, that’s a timed event timeout return None if len(ret_list) != 1: if ret_list[-1] == '^M': ret_list.pop(-1) ret_list = [char if char != '^M' else '^J' for char in ret_list] if self.escape: # Modify the first char of the list into its escaped version (i.e one or more char) key = ret_list.pop(0) for char in key[::-1]: ret_list.insert(0, char) self.escape = False return ret_list if __name__ == '__main__': import sys keyboard = Keyboard() s = curses.initscr() curses.noecho() curses.cbreak() s.keypad(1) curses.start_color() curses.use_default_colors() curses.init_pair(1, 2, -1) s.attron(curses.A_BOLD | curses.color_pair(1)) s.addstr('Type Ctrl-c to close\n') s.attroff(curses.A_BOLD | curses.color_pair(1)) pressed_chars = [] while True: try: chars = keyboard.get_user_input(s) for char in chars if chars else '': s.addstr('%s ' % (char)) pressed_chars.append(chars) except KeyboardInterrupt: break curses.echo() curses.cbreak() curses.curs_set(1) curses.endwin() for char_list in pressed_chars: if char_list: print(' '.join((char for char in char_list)), end=' ') print() sys.exit(0)