check_win32_key_messages.py

# Python WM_KEYDOWN / WM_KEYUP message checker based on following CreateWindow
# example gist:
# https://gist.github.com/mouseroot/6128651
# (I lost my Spy++ binary...)

from ctypes import *
from ctypes.wintypes import *


WNDPROCTYPE = WINFUNCTYPE(c_int, HWND, c_uint, WPARAM, LPARAM)

WS_EX_APPWINDOW = 0x40000
WS_OVERLAPPEDWINDOW = 0xcf0000
WS_CAPTION = 0xc00000

SW_SHOWNORMAL = 1
SW_SHOW = 5

CS_HREDRAW = 2
CS_VREDRAW = 1

CW_USEDEFAULT = 0x80000000

WM_DESTROY = 2

WHITE_BRUSH = 0


class WNDCLASSEX(ctypes.Structure):
    _fields_ = [
        ('cbSize', c_uint),
        ('style', c_uint),
        ('lpfnWndProc', WNDPROCTYPE),
        ('cbClsExtra', c_int),
        ('cbWndExtra', c_int),
        ('hInstance', HANDLE),
        ('hIcon', HANDLE),
        ('hCursor', HANDLE),
        ('hBrush', HANDLE),
        ('lpszMenuName', LPCWSTR),
        ('lpszClassName', LPCWSTR),
        ('hIconSm', HANDLE),
    ]


windll.user32.DefWindowProcW.argtypes = (HWND, c_uint, WPARAM, LPARAM)

WM_KEYDOWN = 0x0100
WM_KEYUP = 0x0101


def window_procedure(h_wnd, msg, w_param, lParam):
    if msg == WM_DESTROY:
        windll.user32.PostQuitMessage(0)
    elif msg == 0x0100:
        print(
            'WM_KEYDOWN: nVirtkey=%04x, cRepeat=%04x, scanCode=%02x, fExtended=%s' % (
                w_param,
                lParam & 0x0000ffff,
                (lParam & 0x00ff0000) >> 16,
                bool(lParam & 0x01000000),
            )
        )
    elif msg == 0x0101:
        print(
            'WM_KEYUP: nVirtkey=%04x, cRepeat=%04x, scanCode=%02x, fExtended=%s' % (
                w_param,
                lParam & 0x0000ffff,
                (lParam & 0x00ff0000) >> 16,
                bool(lParam & 0x01000000),
            )
        )
    else:
        return windll.user32.DefWindowProcW(h_wnd, msg, w_param, lParam)
  
    return 0


def main():
    WndProc = WNDPROCTYPE(window_procedure)
    hInst = windll.kernel32.GetModuleHandleW(0)
    wclassName = 'My Python Win32 Class'
    wname = 'My message test window'
    
    wndClass = WNDCLASSEX()
    wndClass.cbSize = sizeof(WNDCLASSEX)
    wndClass.style = CS_HREDRAW | CS_VREDRAW
    wndClass.lpfnWndProc = WndProc
    wndClass.cbClsExtra = 0
    wndClass.cbWndExtra = 0
    wndClass.hInstance = hInst
    wndClass.hIcon = 0
    wndClass.hCursor = 0
    wndClass.hBrush = windll.gdi32.GetStockObject(WHITE_BRUSH)
    wndClass.lpszMenuName = 0
    wndClass.lpszClassName = wclassName
    wndClass.hIconSm = 0
    
    regRes = windll.user32.RegisterClassExW(byref(wndClass))
    hWnd = windll.user32.CreateWindowExW(
        0,
        wclassName,
        wname,
        WS_OVERLAPPEDWINDOW | WS_CAPTION,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        300,
        300,
        0,
        0,
        hInst,
        0
    )

    if not hWnd:
        print('Failed to create window')
        exit(-1)

    windll.user32.ShowWindow(hWnd, SW_SHOW)
    windll.user32.UpdateWindow(hWnd)

    msg = MSG()
    lpmsg = pointer(msg)

    print('Ready')

    while windll.user32.GetMessageW(lpmsg, 0, 0, 0) != 0:
        windll.user32.TranslateMessage(lpmsg)
        windll.user32.DispatchMessageW(lpmsg)


if __name__ == '__main__':
    main()