问题
I've created a python script in which an event needs to be executed each time I press the Super (or WinKey) on my keyboard.
How can one achieve this without the python process being "focused" - as it is running in the background waiting for the key to be pressed to execute the event?
I've seen a lot of posts around the web showing me how to read input - but they have all required one to have the process "focused" and none have showed me how to capture the Super (or WinKey) using a python script.
I'm running Ubuntu 9.10.
回答1:
This allows me to get the state of modifier keys on my *nix system.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""OSD Neo2
========
On screen display for learning the keyboard layout Neo2
Copyright (c) 2009 Martin Zuther (http://www.mzuther.de/)
This program 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.
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
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 <http://www.gnu.org/licenses/>.
Thank you for using free software!
"""
# Here follows a plea in German to keep the comments in English so
# that you may understand them, dear visitor ...
#
# Meine Kommentare in den Quellcodes sind absichtlich auf Englisch
# gehalten, damit Leute, die im Internet nach Lösungen suchen, den
# Code nachvollziehen können. Daher bitte ich darum, zusätzliche
# Kommentare ebenfalls auf Englisch zu schreiben. Vielen Dank!
import ctypes
import ctypes.util
import gettext
import os
import types
# initialise localisation settings
module_path = os.path.dirname(os.path.realpath(__file__))
gettext.bindtextdomain('OSDneo2', os.path.join(module_path, 'po/'))
gettext.textdomain('OSDneo2')
_ = gettext.lgettext
class SimpleXkbWrapper:
"""
Far from complete wrapper for the "X Keyboard Extension" (well, to
be honest, it just wraps what I need using Python's "ctypes"
library <g>).
"""
# set this to true to get lots of debugging information (and
# considerably slow things down)
DEBUG_XKB = False
# "C defines" from file /usr/include/X11/extensions/XKB.h (Ubuntu 9.04):
# $XFree86: xc/include/extensions/XKB.h,v 1.5tsi Exp $
#
# XkbUseCoreKbd is used to specify the core keyboard without having to
# look up its X input extension identifier.
XkbUseCoreKbd = 0x0100
# "C defines" from file /usr/include/X11/XKBlib.h (Ubuntu 9.04):
# $XFree86: xc/lib/X11/XKBlib.h,v 3.5 2003/04/17 02:06:31 dawes Exp $ #
#
# XkbOpenDisplay error codes
XkbOD_Success = 0
XkbOD_BadLibraryVersion = 1
XkbOD_ConnectionRefused = 2
XkbOD_NonXkbServer = 3
XkbOD_BadServerVersion = 4
# "C typedef" from file /usr/include/X11/extensions/XKBstr.h (Ubuntu 9.04):
# $Xorg: XKBstr.h,v 1.3 2000/08/18 04:05:45 coskrey Exp $
#
# Common data structures and access macros
#
# typedef struct _XkbStateRec {
# unsigned char group;
# unsigned char locked_group;
# unsigned short base_group;
# unsigned short latched_group;
# unsigned char mods;
# unsigned char base_mods;
# unsigned char latched_mods;
# unsigned char locked_mods;
# unsigned char compat_state;
# unsigned char grab_mods;
# unsigned char compat_grab_mods;
# unsigned char lookup_mods;
# unsigned char compat_lookup_mods;
# unsigned short ptr_buttons;
# } XkbStateRec,*XkbStatePtr;
class XkbStateRec(ctypes.Structure):
_fields_ = [
('group', ctypes.c_ubyte), \
('locked_group', ctypes.c_ubyte), \
('base_group', ctypes.c_ushort), \
('latched_group', ctypes.c_ushort), \
('mods', ctypes.c_ubyte), \
('base_mods', ctypes.c_ubyte), \
('latched_mods', ctypes.c_ubyte), \
('locked_mods', ctypes.c_ubyte), \
('compat_state', ctypes.c_ubyte), \
('grab_mods', ctypes.c_ubyte), \
('compat_grab_mods', ctypes.c_ubyte), \
('lookup_mods', ctypes.c_ubyte), \
('compat_lookup_mods', ctypes.c_ubyte), \
('ptr_buttons', ctypes.c_ushort) \
]
# "C defines" from file /usr/include/X11/X.h (Ubuntu 9.04):
# $XFree86: xc/include/X.h,v 1.6 2003/07/09 15:27:28 tsi Exp $
#
# Key masks. Used as modifiers to GrabButton and GrabKey, results of
# QueryPointer, state in various key-, mouse-, and button-related
# events.
ShiftMask = 1
LockMask = 2
ControlMask = 4
Mod1Mask = 8
Mod2Mask = 16
Mod3Mask = 32
Mod4Mask = 64
Mod5Mask = 128
def __init__(self):
# dynamically link to "X Keyboard Extension" library
library_xf86misc = ctypes.CDLL(ctypes.util.find_library('Xxf86misc'))
# print debugging information if requested
if self.DEBUG_XKB:
print
print ' %s' % library_xf86misc
# define "ctypes" prototype for the function
#
# Display *XkbOpenDisplay(display_name, event_rtrn, error_rtrn,
# major_in_out, minor_in_out, reason_rtrn)
#
# char * display_name;
# int * event_rtrn;
# int * error_rtrn;
# int * major_in_out;
# int * minor_in_out;
# int * reason_rtrn;
paramflags_xkbopendisplay = \
(1, 'display_name'), \
(2, 'event_rtrn'), \
(2, 'error_rtrn'), \
(3, 'major_in_out'), \
(3, 'minor_in_out'), \
(2, 'reason_rtrn')
prototype_xkbopendisplay = ctypes.CFUNCTYPE( \
ctypes.c_uint, \
ctypes.c_char_p, \
ctypes.POINTER(ctypes.c_int), \
ctypes.POINTER(ctypes.c_int), \
ctypes.POINTER(ctypes.c_int), \
ctypes.POINTER(ctypes.c_int), \
ctypes.POINTER(ctypes.c_int) \
)
# set-up function (low-level)
self.__XkbOpenDisplay__ = prototype_xkbopendisplay( \
('XkbOpenDisplay', library_xf86misc), \
paramflags_xkbopendisplay \
)
# define error handler
def errcheck_xkbopendisplay(result, func, args):
# print debugging information if requested
if self.DEBUG_XKB:
print
print ' [XkbOpenDisplay]'
print ' Display: %#010x' % result
print ' display_name: %s' % args[0].value
print ' event_rtrn: %d' % args[1].value
print ' error_rtrn: %d' % args[2].value
print ' major_in_out: %d' % args[3].value
print ' minor_in_out: %d' % args[4].value
print ' reason_rt: %d' % args[5].value
# function didn't return display handle, so let's see why
# not
if result == 0:
# values were taken from file /usr/include/X11/XKBlib.h (Ubuntu 9.04):
# $XFree86: xc/lib/X11/XKBlib.h,v 3.5 2003/04/17 02:06:31 dawes Exp $ #
error_id = args[5].value
if error_id == self.XkbOD_Success:
error_name = 'XkbOD_Success'
elif error_id == self.XkbOD_BadLibraryVersion:
error_name = 'XkbOD_BadLibraryVersion'
elif error_id == self.XkbOD_ConnectionRefused:
error_name = 'XkbOD_ConnectionRefused'
elif error_id == self.XkbOD_NonXkbServer:
error_name = 'XkbOD_NonXkbServer'
elif error_id == self.XkbOD_BadServerVersion:
error_name = 'XkbOD_BadServerVersion'
else:
error_name = _('undefined')
error_message = \
_('"XkbOpenDisplay" reported an error (%(error_name)s).') % \
{'error_name': error_name}
raise OSError(error_message)
# return display handle and all function arguments
return (ctypes.c_uint(result), args)
# connect error handler to function
self.__XkbOpenDisplay__.errcheck = errcheck_xkbopendisplay
# define "ctypes" prototype for the function
#
# Bool XkbGetState(display, device_spec, state_return)
#
# Display * display;
# unsigned int device_spec;
# XkbStatePtr state_return;
paramflags_xkbgetstate = \
(1, 'display'), \
(1, 'device_spec'), \
(3, 'state_return')
prototype_xkbgetstate = ctypes.CFUNCTYPE( \
ctypes.c_int, # Python 2.5 doesn't yet know c_bool \
ctypes.c_uint, \
ctypes.c_uint, \
ctypes.POINTER(self.XkbStateRec) \
)
# set-up function (low-level)
self.__XkbGetState__ = prototype_xkbgetstate( \
('XkbGetState', library_xf86misc), \
paramflags_xkbgetstate \
)
# define error handler
def errcheck_xkbgetstate(result, func, args):
# print debugging information if requested
if self.DEBUG_XKB:
print
print ' [XkbGetState]'
print ' Status: %s' % result
print ' display: %#010x' % args[0].value
print ' device_spec: %d\n' % args[1].value
print ' state_return.group: %d' % \
args[2].group
print ' state_return.locked_group: %d' % \
args[2].locked_group
print ' state_return.base_group: %d' % \
args[2].base_group
print ' state_return.latched_group: %d' % \
args[2].latched_group
print ' state_return.mods: %d' % \
args[2].mods
print ' state_return.base_mods: %d' % \
args[2].base_mods
print ' state_return.latched_mods: %d' % \
args[2].latched_mods
print ' state_return.locked_mods: %d' % \
args[2].locked_mods
print ' state_return.compat_state: %d' % \
args[2].compat_state
print ' state_return.grab_mods: %d' % \
args[2].grab_mods
print ' state_return.compat_grab_mods: %d' % \
args[2].compat_grab_mods
print ' state_return.lookup_mods: %d' % \
args[2].lookup_mods
print ' state_return.compat_lookup_mods: %d' % \
args[2].compat_lookup_mods
print ' state_return.ptr_buttons: %d\n' % \
args[2].ptr_buttons
print ' Mask mods base_mods latched_mods locked_mods compat_state'
print ' --------------------------------------------------------------------------'
print ' ShiftMask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.ShiftMask) != 0, \
(args[2].base_mods & self.ShiftMask) != 0, \
(args[2].latched_mods & self.ShiftMask) != 0, \
(args[2].locked_mods & self.ShiftMask) != 0, \
(args[2].compat_state & self.ShiftMask) != 0)
print ' LockMask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.LockMask) != 0, \
(args[2].base_mods & self.LockMask) != 0, \
(args[2].latched_mods & self.LockMask) != 0, \
(args[2].locked_mods & self.LockMask) != 0, \
(args[2].compat_state & self.LockMask) != 0)
print ' ControlMask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.ControlMask) != 0, \
(args[2].base_mods & self.ControlMask) != 0, \
(args[2].latched_mods & self.ControlMask) != 0, \
(args[2].locked_mods & self.ControlMask) != 0, \
(args[2].compat_state & self.ControlMask) != 0)
print ' Mod1Mask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.Mod1Mask) != 0, \
(args[2].base_mods & self.Mod1Mask) != 0, \
(args[2].latched_mods & self.Mod1Mask) != 0, \
(args[2].locked_mods & self.Mod1Mask) != 0, \
(args[2].compat_state & self.Mod1Mask) != 0)
print ' Mod2Mask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.Mod2Mask) != 0, \
(args[2].base_mods & self.Mod2Mask) != 0, \
(args[2].latched_mods & self.Mod2Mask) != 0, \
(args[2].locked_mods & self.Mod2Mask) != 0, \
(args[2].compat_state & self.Mod2Mask) != 0)
print ' Mod3Mask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.Mod3Mask) != 0, \
(args[2].base_mods & self.Mod3Mask) != 0, \
(args[2].latched_mods & self.Mod3Mask) != 0, \
(args[2].locked_mods & self.Mod3Mask) != 0, \
(args[2].compat_state & self.Mod3Mask) != 0)
print ' Mod4Mask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.Mod4Mask) != 0, \
(args[2].base_mods & self.Mod4Mask) != 0, \
(args[2].latched_mods & self.Mod4Mask) != 0, \
(args[2].locked_mods & self.Mod4Mask) != 0, \
(args[2].compat_state & self.Mod4Mask) != 0)
print ' Mod5Mask %-5s %-5s %-5s %-5s %-5s' % \
((args[2].mods & self.Mod5Mask) != 0, \
(args[2].base_mods & self.Mod5Mask) != 0, \
(args[2].latched_mods & self.Mod5Mask) != 0, \
(args[2].locked_mods & self.Mod5Mask) != 0, \
(args[2].compat_state & self.Mod5Mask) != 0)
# return function return value and all function arguments
return (result, args)
# connect error handler to function
self.__XkbGetState__.errcheck = errcheck_xkbgetstate
# define high-level version of "XkbOpenDisplay"
def XkbOpenDisplay(self, display_name, major_in_out, minor_in_out):
# if we don't do type checking, nobody ever will
assert (type(display_name) == types.NoneType) or \
(type(display_name) == types.StringType)
assert type(major_in_out) == types.IntType
assert type(minor_in_out) == types.IntType
# convert function arguments to "ctypes", ...
__display_name__ = ctypes.c_char_p(display_name)
__major_in_out__ = ctypes.c_int(major_in_out)
__minor_in_out__ = ctypes.c_int(minor_in_out)
# ... call low-level function ...
ret = self.__XkbOpenDisplay__(__display_name__, __major_in_out__, \
__minor_in_out__)
# ... and return converted return value and function arguments
return {'display_handle': ret[0].value, \
'server_major_version': ret[1][3].value, \
'server_minor_version': ret[1][4].value}
# define high-level version of "XkbGetState"
def XkbGetState(self, display_handle, device_spec):
# if we don't do type checking, nobody ever will
assert type(display_handle) == types.LongType
assert type(device_spec) == types.IntType
# convert function arguments to "ctypes", ...
__display_handle__ = ctypes.c_uint(display_handle)
__device_spec__ = ctypes.c_uint(device_spec)
__xkbstaterec__ = self.XkbStateRec()
# ... call low-level function ...
ret = self.__XkbGetState__(__display_handle__, __device_spec__, \
__xkbstaterec__)
# ... and return converted function argument
xkbstaterec = ret[1][2]
return xkbstaterec
# extract modifier status using bitmasks
def ExtractLocks(self, xkbstaterec):
return {'group': xkbstaterec.group, \
'shift': \
(xkbstaterec.base_mods & self.ShiftMask) != 0, \
'shift_lock': \
(xkbstaterec.locked_mods & self.ShiftMask) != 0, \
'lock': \
(xkbstaterec.base_mods & self.LockMask) != 0, \
'lock_lock': \
(xkbstaterec.locked_mods & self.LockMask) != 0, \
'control': \
(xkbstaterec.base_mods & self.ControlMask) != 0, \
'control_lock': \
(xkbstaterec.locked_mods & self.ControlMask) != 0, \
'mod1': \
(xkbstaterec.base_mods & self.Mod1Mask) != 0, \
'mod1_lock': \
(xkbstaterec.locked_mods & self.Mod1Mask) != 0, \
'mod2': \
(xkbstaterec.base_mods & self.Mod2Mask) != 0, \
'mod2_lock': \
(xkbstaterec.locked_mods & self.Mod2Mask) != 0, \
'mod3': \
(xkbstaterec.base_mods & self.Mod3Mask) != 0, \
'mod3_lock': \
(xkbstaterec.locked_mods & self.Mod3Mask) != 0, \
'mod4': \
(xkbstaterec.base_mods & self.Mod4Mask) != 0, \
'mod4_lock': \
(xkbstaterec.locked_mods & self.Mod4Mask) != 0, \
'mod5': \
(xkbstaterec.base_mods & self.Mod5Mask) != 0, \
'mod5_lock': \
(xkbstaterec.locked_mods & self.Mod5Mask) != 0}
To call state to a dictionary,from another file, just call from FILENAME import * and do the following:
# simple demonstration of this wrapper
xkb = SimpleXkbWrapper()
# initialise wrapper for the X Keyboard Extension (v1.0) and
# open connection to default X display
display_name = None
major_in_out = 1
minor_in_out = 0
try:
ret = xkb.XkbOpenDisplay(display_name, major_in_out, minor_in_out)
except OSError, error:
print
print ' Error: %s' % error
print
exit(1)
# ... get modifier state of core keyboard ...
display_handle = ret['display_handle']
device_spec = xkb.XkbUseCoreKbd
xkbstaterec = xkb.XkbGetState(display_handle, device_spec)
# ... and extract and the information we need
print xkb.ExtractLocks(xkbstaterec)
Cheers to the creator whose code can be found here, and to Jason Orendorffl for drawing my attention to it.
回答2:
My previous answer apparently was completely wrong, sorry. I think the correct approach would be to read from /dev/input/event1 (?)
This short test showed scancodes for me, even if the terminal did not have focus:
from struct import unpack
port = open("/dev/input/event1","rb")
while 1:
a,b,c,d = unpack("4B",port.read(4))
print a,b,c,d
I do not know if /dev/input/event1 is always the keyboard or how to determine which one is, but at least for me it worked
回答3:
You can use PyUserInput for this purpose, which is a cross-platform solution, compatible, in your case, with X11.
Example with Super:
from pykeyboard import PyKeyboardEvent
class MonitorSuper(PyKeyboardEvent):
def tap(self, keycode, character, press):
'''Monitor Super key.'''
if character == 'Super_L':
if press:
print('Super pressed')
else:
print('Super released')
mon = MonitorSuper()
mon.run()
回答4:
If you need to work on Linux, I think you need to somehow monitor for X events.
You can see all events if you run the command "xev" - so I am sure that X provides an interface to all events. A quick googling finds Python X library that probably gives you the stuff you need.
You can download it here.
来源：https://stackoverflow.com/questions/1859049/check-if-key-is-pressed-using-python-a-daemon-in-the-background