8

我想在普通键盘上实现键和弦，我想我使用 python xlib。为此，程序必须全局吞下所有关键事件，然后才允许它们通过。

我目前的测试只是抓住了“1”键。如果按下此键，它会调用一个处理程序，该处理程序通过 xtest.fake_input 将“x”发送到焦点窗口。因为我只抓住“1”键，所以应该没有问题，对吧？但不知何故，处理程序再次被调用，因为“x”被按下。事实上，在我输入“1”的那一刻，程序正在监听所有键。这可能与打电话有关

display.allow_events(X.ReplayKeyboard, X.CurrentTime)

处理事件后，但如果我不这样做，一切都会冻结。

对于最终程序，收听行为的变化并不真正相关，但我必须能够将假事件与用户事件区分开来。要做到这一点，我只是快进 display.next_event()，但这并不理想，因为用户可能在那个确切的时刻打字，而那些击键会丢失。

我尝试在通过发送和清空事件队列期间释放密钥抓取

display.flush()
display.sync()

但这无济于事。

那么，任何想法如何识别或忽略虚假输入事件以及为什么我突然听到所有按键（和释放）？

xlib 非常令人沮丧。

from Xlib.display import Display
import Xlib
from Xlib import X
import Xlib.XK
import sys
import signal 

display = None
root = None

def handle_event(aEvent):
    print "handle!"
    send_key("x")

def send_key(emulated_key):

    global display,root
    print "send key"
    # ungrabbing doesnt help
    root.ungrab_key(10,X.AnyModifier) 
    window = display.get_input_focus()._data["focus"]
    # Generate the correct keycode
    keysym = Xlib.XK.string_to_keysym(emulated_key)
    keycode = display.keysym_to_keycode(keysym)
    # Send a fake keypress via xtestaaa
    Xlib.ext.xtest.fake_input(window, Xlib.X.KeyPress, keycode)
    Xlib.ext.xtest.fake_input(window, Xlib.X.KeyRelease, keycode)
    display.flush()
    display.sync()
    # fast forward those two events,this seems a bit hacky, 
    # what if theres another keyevent coming in at that exact time?
    while display.pending_events():
        display.next_event()
    #
    root.grab_key(10, X.AnyModifier, True,X.GrabModeSync, X.GrabModeSync)

def main():
    # current display
    global display,root
    display = Display()
    root = display.screen().root

    # we tell the X server we want to catch keyPress event
    root.change_attributes(event_mask = X.KeyPressMask)
    # just grab the "1"-key for now
    root.grab_key(10, X.AnyModifier, True,X.GrabModeSync, X.GrabModeSync)
    # while experimenting everything could freeze, so exit after 10 seconds
    signal.signal(signal.SIGALRM, lambda a,b:sys.exit(1))
    signal.alarm(10)
    while 1:
        event = display.next_event()
        print "event"
        #if i dont call this, the whole thing freezes
        display.allow_events(X.ReplayKeyboard, X.CurrentTime)
        handle_event(event)

if __name__ == '__main__':
    main()
4

1 回答 1

6

我发现了问题。我几乎可以肯定 xtest.fake_input 做了一些奇怪的事情，因为当我手动发送按键和 -releases （使用我找到的一些代码）时，它可以工作

这是一个示例，它仅在 keypress 上吞下“1”键，并在 keyrelease 上将“x”发送到焦点窗口：

from Xlib.display import Display
import Xlib
from Xlib import X
import Xlib.XK
import sys
import signal 
import time
display = None
root = None

def handle_event(event):
    print "handle!"
    if (event.type == X.KeyRelease):
        send_key("x")

# from http://shallowsky.com/software/crikey/pykey-0.1 
def send_key(emulated_key):
    shift_mask = 0 # or Xlib.X.ShiftMask
    window = display.get_input_focus()._data["focus"]
    keysym = Xlib.XK.string_to_keysym(emulated_key)
    keycode = display.keysym_to_keycode(keysym)
    event = Xlib.protocol.event.KeyPress(
        time = int(time.time()),
        root = root,
        window = window,
        same_screen = 0, child = Xlib.X.NONE,
        root_x = 0, root_y = 0, event_x = 0, event_y = 0,
        state = shift_mask,
        detail = keycode
        )
    window.send_event(event, propagate = True)
    event = Xlib.protocol.event.KeyRelease(
        time = int(time.time()),
        root = display.screen().root,
        window = window,
        same_screen = 0, child = Xlib.X.NONE,
        root_x = 0, root_y = 0, event_x = 0, event_y = 0,
        state = shift_mask,
        detail = keycode
        )
    window.send_event(event, propagate = True)

def main():
    # current display
    global display,root
    display = Display()
    root = display.screen().root

    # we tell the X server we want to catch keyPress event
    root.change_attributes(event_mask = X.KeyPressMask|X.KeyReleaseMask)
    # just grab the "1"-key for now
    root.grab_key(10, 0, True,X.GrabModeSync, X.GrabModeSync)

    signal.signal(signal.SIGALRM, lambda a,b:sys.exit(1))
    signal.alarm(10)
    while 1:
        event = display.next_event()
        print "event"
        handle_event(event)
        display.allow_events(X.AsyncKeyboard, X.CurrentTime)            

if __name__ == '__main__':
    main()
于 2013-08-05T15:50:37.163 回答