codekingpro/portable-devtools

1# A sample originally provided by Richard Bell, and modified by Mark Hammond.2 3# This sample demonstrates how to use COM events in a free-threaded world.4# In this world, there is no need to marshall calls across threads, so5# no message loops are needed at all.  This means regular cross-thread6# sychronization can be used.  In this sample we just wait on win32 event7# objects.8 9# See also ieEventsApartmentThreaded.py for how to do this in an10# aparment-threaded world, where thread-marshalling complicates things.11 12# NOTE: This example uses Internet Explorer, but it should not be considerd13# a "best-practices" for writing against IE events, but for working with14# events in general. For example:15# * The first OnDocumentComplete event is not a reliable indicator that the16#   URL has completed loading17# * As we are demonstrating the most efficient way of handling events, when18#   running this sample you will see an IE Windows briefly appear, but19#   vanish without ever being repainted.20 21import sys22 23sys.coinit_flags = 0  # specify free threading24 25 26import pythoncom27import win32api28import win32com.client29import win32event30 31 32# The print statements indicate that COM has actually started another thread33# and will deliver the events to that thread (ie, the events do not actually34# fire on our main thread.35class ExplorerEvents:36    def __init__(self):37        # We reuse this event for all events.38        self.event = win32event.CreateEvent(None, 0, 0, None)39 40    def OnDocumentComplete(self, pDisp=pythoncom.Empty, URL=pythoncom.Empty):41        #42        # Caution:  Since the main thread and events thread(s) are different43        # it may be necessary to serialize access to shared data.  Because44        # this is a simple test case, that is not required here.  Your45        # situation may be different.   Caveat programmer.46        #47        thread = win32api.GetCurrentThreadId()48        print("OnDocumentComplete event processed on thread %d" % thread)49        # Set the event our main thread is waiting on.50        win32event.SetEvent(self.event)51 52    def OnQuit(self):53        thread = win32api.GetCurrentThreadId()54        print("OnQuit event processed on thread %d" % thread)55        win32event.SetEvent(self.event)56 57 58def TestExplorerEvents():59    iexplore = win32com.client.DispatchWithEvents(60        "InternetExplorer.Application", ExplorerEvents61    )62 63    thread = win32api.GetCurrentThreadId()64    print("TestExplorerEvents created IE object on thread %d" % thread)65 66    iexplore.Visible = 167    try:68        iexplore.Navigate(win32api.GetFullPathName("..\\readme.html"))69    except pythoncom.com_error as details:70        print("Warning - could not open the test HTML file", details)71 72    # In this free-threaded example, we can simply wait until an event has73    # been set - we will give it 2 seconds before giving up.74    rc = win32event.WaitForSingleObject(iexplore.event, 2000)75    if rc != win32event.WAIT_OBJECT_0:76        print("Document load event FAILED to fire!!!")77 78    iexplore.Quit()79    # Now we can do the same thing to wait for exit!80    # Although Quit generates events, in this free-threaded world we81    # do *not* need to run any message pumps.82 83    rc = win32event.WaitForSingleObject(iexplore.event, 2000)84    if rc != win32event.WAIT_OBJECT_0:85        print("OnQuit event FAILED to fire!!!")86 87    iexplore = None88    print("Finished the IE event sample!")89 90 91if __name__ == "__main__":92    TestExplorerEvents()93