Block pyhook from so-generated keystrokes?
-
11-12-2019 - |
Question
I'm using pyhook
and pyhk
to map keystrokes on a windows XP machine, and it works fine except for when the keystroke (say, ctrl+z) already exists in the application. In that case, the ctrl+z passes to the application and triggers the action that has been mapped to it.
If you are familiar with autohotkey
, note that autohotkey
gets around this by defining hotkeys that can optionally be passed to the underlying application. Here's a bit of codes that gets at the idea. Note that I'm trying to keep track of when the ctrl key is down.
import pythoncom, pyHook
control_down = False
def OnKeyboardEvent_up(event):
global control_down
if event.Key=='Lcontrol' or event.Key=='Rcontrol':
control_down=False
return True
def OnKeyboardEvent(event,action=None,key='Z',context=None):
global control_down
if event.Key=='Lcontrol' or event.Key=='Rcontrol':
control_down=True
if control_down and event.Key==key:
print 'do something'
return False
if event.Key=='Pause':
win32gui.PostQuitMessage(1)
return False
# return True to pass the event to other handlers
return True
if __name__ == '__main__':
hm = pyHook.HookManager()
hm.KeyDown = OnKeyboardEvent
hm.KeyUp = OnKeyboardEvent_up
hm.HookKeyboard() # set the hook
pythoncom.PumpMessages() # wait forever
Any help appreciated.
Thanks!
Solution
If you're insterested in Windows only, you can use win API, e.g. via ctypes:
>>> from ctypes import windll
>>> windll.user32.RegisterHotKey(0, -1, 0x0002, 0x5a)
After running these lines of code Ctrl (code = 0x0002) + Z (code = 0x5a) combination doesn't work any more in Python REPL.
So you should better look at what windows are those hotkey registered. More information you can find in MSDN: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646309(v=vs.85).aspx
OTHER TIPS
I may totally wrong here, but from my understanding of the pyHook documentation, in order to prevent the key presses from being sent to another application you need to change the return True
in def OnKeyboardEvent_up(event):
and OnKeyboardEvent(event,action=None,key='Z',context=None):
to return False
(or anything else other than True
.