Window changes test command module

_window_changes_test.py

# Window changes test command module
# This should be placed in the natlink user folder.

import time
from threading import Thread, Event

from ctypes import windll
from ctypes.wintypes import DWORD, HANDLE, HWND, LONG, WINFUNCTYPE

import pythoncom

from dragonfly import Window, get_engine


class ObserverThread(Thread):
    def __init__(self):
        Thread.__init__(self)
        self._stop_event = Event()
        self.daemon = True

    def stop(self):
        self._stop_event.set()

    def run(self):
        WinEventProcType = WINFUNCTYPE(None, HANDLE, DWORD, HWND, LONG,
                                           LONG, DWORD, DWORD)

        last_foreground_window = [None]

        def callback(hWinEventHook, event, hwnd, idObject, idChild,
                     dwEventThread, dwmsEventTime):
            window = Window.get_foreground()
            # Note: hwnd doesn't always match window.handle, even when
            # foreground window changed (and sometimes it didn't change)
            if window != last_foreground_window[0]:
                print(window)
                last_foreground_window[0] = window

        def set_hook(win_event_proc, event_type):
            return windll.user32.SetWinEventHook(
                event_type, event_type, 0, win_event_proc, 0, 0,
                0)

        win_event_proc = WinEventProcType(callback)
        windll.user32.SetWinEventHook.restype = HANDLE

        [set_hook(win_event_proc, et) for et in
         {3, 32780, }]

        # Recognize speech, call timer functions and handle window change
        # events in a loop.
        while not self._stop_event.is_set():
            pythoncom.PumpWaitingMessages()
            time.sleep(0.01)


observer_thread = ObserverThread()
observer_thread.start()

def timer_func():
    observer_thread.join(0.001)

timer = get_engine().create_timer(timer_func, 0.05)


def unload():
    if observer_thread.is_alive():
        observer_thread.stop()
        observer_thread.join(5)
    timer.stop()