0 Enumerating Visible Windows on Windows with ctypes.md

Enumerating Visible Windows on Windows with ctypes

• Enumerates all top-level visible windows using EnumWindows, then filters to windows that are visible and have a non-empty title (IsWindowVisible, GetWindowText*).
• Enriches each window with process and metadata by collecting the window class (GetClassNameW), PID (GetWindowThreadProcessId), and executable path (OpenProcess + QueryFullProcessImageNameW).
• Extracts and interprets window style flags via GetWindowLongPtrW/GetWindowLongW to report key attributes such as DISABLED, TOPMOST, TOOLWIN, and APPWIN alongside raw STYLE/EXSTYLE hex values.

main.py

import ctypes
from ctypes import wintypes
import sys

try:
    sys.stdout.reconfigure(encoding="utf-8", errors="replace")
except Exception:
    pass

user32 = ctypes.WinDLL("user32", use_last_error=True)
kernel32 = ctypes.WinDLL("kernel32", use_last_error=True)

EnumWindowsProc = ctypes.WINFUNCTYPE(wintypes.BOOL, wintypes.HWND, wintypes.LPARAM)

PROCESS_QUERY_LIMITED_INFORMATION = 0x1000

# --- GWL / style constants ---
GWL_STYLE   = -16
GWL_EXSTYLE = -20

WS_DISABLED      = 0x08000000

WS_EX_TOPMOST    = 0x00000008
WS_EX_TOOLWINDOW = 0x00000080
WS_EX_APPWINDOW  = 0x00040000

# --- prototypes ---
user32.EnumWindows.argtypes = [EnumWindowsProc, wintypes.LPARAM]
user32.EnumWindows.restype = wintypes.BOOL

user32.IsWindowVisible.argtypes = [wintypes.HWND]
user32.IsWindowVisible.restype = wintypes.BOOL

user32.GetWindowTextLengthW.argtypes = [wintypes.HWND]
user32.GetWindowTextLengthW.restype = ctypes.c_int

user32.GetWindowTextW.argtypes = [wintypes.HWND, wintypes.LPWSTR, ctypes.c_int]
user32.GetWindowTextW.restype = ctypes.c_int

user32.GetClassNameW.argtypes = [wintypes.HWND, wintypes.LPWSTR, ctypes.c_int]
user32.GetClassNameW.restype = ctypes.c_int

user32.GetWindowThreadProcessId.argtypes = [wintypes.HWND, ctypes.POINTER(wintypes.DWORD)]
user32.GetWindowThreadProcessId.restype = wintypes.DWORD

kernel32.OpenProcess.argtypes = [wintypes.DWORD, wintypes.BOOL, wintypes.DWORD]
kernel32.OpenProcess.restype = wintypes.HANDLE

kernel32.CloseHandle.argtypes = [wintypes.HANDLE]
kernel32.CloseHandle.restype = wintypes.BOOL

kernel32.QueryFullProcessImageNameW.argtypes = [
    wintypes.HANDLE, wintypes.DWORD, wintypes.LPWSTR, ctypes.POINTER(wintypes.DWORD)
]
kernel32.QueryFullProcessImageNameW.restype = wintypes.BOOL

# --- GetWindowLongPtrW (32/64対応) ---
if ctypes.sizeof(ctypes.c_void_p) == 8:
    user32.GetWindowLongPtrW.argtypes = [wintypes.HWND, ctypes.c_int]
    user32.GetWindowLongPtrW.restype = ctypes.c_longlong
    def get_window_long_ptr(hwnd, index) -> int:
        return int(user32.GetWindowLongPtrW(hwnd, index))
else:
    user32.GetWindowLongW.argtypes = [wintypes.HWND, ctypes.c_int]
    user32.GetWindowLongW.restype = ctypes.c_long
    def get_window_long_ptr(hwnd, index) -> int:
        return int(user32.GetWindowLongW(hwnd, index))


def get_window_title(hwnd: int) -> str:
    length = user32.GetWindowTextLengthW(hwnd)
    if length <= 0:
        return ""
    buf = ctypes.create_unicode_buffer(length + 1)
    user32.GetWindowTextW(hwnd, buf, length + 1)
    return buf.value


def get_window_class(hwnd: int) -> str:
    buf = ctypes.create_unicode_buffer(256)
    n = user32.GetClassNameW(hwnd, buf, len(buf))
    return buf.value if n > 0 else ""


def get_pid(hwnd: int) -> int:
    pid = wintypes.DWORD(0)
    user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
    return int(pid.value)


def get_process_image_path(pid: int) -> str:
    hproc = kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, False, pid)
    if not hproc:
        return ""
    try:
        size = wintypes.DWORD(4096)
        buf = ctypes.create_unicode_buffer(size.value)
        if kernel32.QueryFullProcessImageNameW(hproc, 0, buf, ctypes.byref(size)):
            return buf.value
        return ""
    finally:
        kernel32.CloseHandle(hproc)


def get_styles(hwnd: int) -> tuple[int, int]:
    style = get_window_long_ptr(hwnd, GWL_STYLE)
    exstyle = get_window_long_ptr(hwnd, GWL_EXSTYLE)
    return style, exstyle


def has_flag(value: int, flag: int) -> bool:
    return (value & flag) == flag


def enum_windows():
    results = []

    @EnumWindowsProc
    def callback(hwnd, lparam):
        if not user32.IsWindowVisible(hwnd):
            return True

        title = get_window_title(hwnd)
        if not title:
            return True

        cls = get_window_class(hwnd)
        pid = get_pid(hwnd)
        image = get_process_image_path(pid)

        style, exstyle = get_styles(hwnd)

        results.append((hwnd, pid, cls, title, image, style, exstyle))
        return True

    if not user32.EnumWindows(callback, 0):
        raise ctypes.WinError(ctypes.get_last_error())

    return results


if __name__ == "__main__":
    for hwnd, pid, cls, title, image, style, exstyle in enum_windows():
        disabled = has_flag(style, WS_DISABLED)
        topmost = has_flag(exstyle, WS_EX_TOPMOST)
        toolwin = has_flag(exstyle, WS_EX_TOOLWINDOW)
        appwin = has_flag(exstyle, WS_EX_APPWINDOW)

        print(
            f"HWND=0x{hwnd:08X} PID={pid:<6} "
            f"DISABLED={int(disabled)} TOPMOST={int(topmost)} TOOLWIN={int(toolwin)} APPWIN={int(appwin)} "
            f"STYLE=0x{style:08X} EXSTYLE=0x{exstyle:08X} "
            f"CLASS={cls} TITLE={title} EXE={image}"
        )