Problems with threaded Hotkey application

[Rsrany]

I've been working on a few gtk applications and need to tie a hot key
catcher into a thread. I am currently finding threaded
user32.GetMessageA do not work.

I have included two programs:
1) a non-threaded version that works
2) a threaded version that doesnt work.

Any constructive suggestions would be helpful

#########################################################
Working non-threaded version:
#########################################################
import sys
from ctypes import *
from ctypes.wintypes import *

# Define the Windows DLLs, constants and types that we need.
user32 = windll.user32

WM_HOTKEY = 0x0312
MOD_ALT = 0x0001
MOD_CONTROL = 0x0002
MOD_SHIFT = 0x0004

class MSG(Structure):
_fields_ = [('hwnd', c_int),
('message', c_uint),
('wParam', c_int),
('lParam', c_int),
('time', c_int),
('pt', POINT)]

# Register a hotkey for Ctrl+Shift+P.
hotkeyId = 1
if not user32.RegisterHotKey(None, hotkeyId, MOD_CONTROL |
MOD_SHIFT, ord('P')):
sys.exit("Failed to register hotkey; maybe someone else
registered it?")

# Spin a message loop waiting for WM_HOTKEY.
while 1 :

msg = MSG()
while user32.GetMessageA(byref(msg), None, 0, 0) != 0:
if msg.message == WM_HOTKEY and msg.wParam == hotkeyId:
print "Yay"
windll.user32.PostQuitMessage(0)
user32.TranslateMessage(byref(msg))
user32.DispatchMessageA(byref(msg))





#################################################
And here is the Non Working Threaded version :
#################################################
import sys
from ctypes import *
from ctypes.wintypes import *
import threading

# Define the Windows DLLs, constants and types that we need.
user32 = windll.user32

WM_HOTKEY = 0x0312
MOD_ALT = 0x0001
MOD_CONTROL = 0x0002
MOD_SHIFT = 0x0004

class MSG(Structure):
_fields_ = [('hwnd', c_int),
('message', c_uint),
('wParam', c_int),
('lParam', c_int),
('time', c_int),
('pt', POINT)]

# Register a hotkey for Ctrl+Shift+P.
hotkeyId = 1
if not user32.RegisterHotKey(None, hotkeyId, MOD_CONTROL |
MOD_SHIFT, ord('P')):
sys.exit("Failed to register hotkey; maybe someone else
registered it?")

class KeyCatch(threading.Thread):

def run(self):

print "TESTING TO MAKE SURE THREAD IS RUNNING!"

# Spin a message loop waiting for WM_HOTKEY.
while 1 :

msg = MSG()
while user32.GetMessageA(byref(msg), None, 0, 0) != 0:
if msg.message == WM_HOTKEY and msg.wParam ==
hotkeyId:
print "Yay"
windll.user32.PostQuitMessage(0)
user32.TranslateMessage(byref(msg))
user32.DispatchMessageA(byref(msg))

GetKey = KeyCatch()
GetKey.start()

while 1:
pass

 

[Tim G]

One obvious point is that, according to:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wceui40/html/cerefWM_HOTKEY.asp

the WM_HOTKEY message is posted to the queue *of the thread which
registered the hotkey*. I haven't yet tried it myself to see, but in
your example the main thread registers the hotkey, and the KeyCatch
thread is waiting to receive it.

TJG

 

[Tim G]

And just to confirm, it does in fact work. If you move the
RegisterHotKey line to within the thread's run method, the thread's
message loop picks up the hotkey press.

 

[Rsrany]

Thanks Tim, that resolved it.