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- # A sample originally provided by Richard Bell, and modified by Mark Hammond.
-
- # This sample demonstrates how to use COM events in a free-threaded world.
- # In this world, there is no need to marshall calls across threads, so
- # no message loops are needed at all. This means regular cross-thread
- # sychronization can be used. In this sample we just wait on win32 event
- # objects.
-
- # See also ieEventsApartmentThreaded.py for how to do this in an
- # aparment-threaded world, where thread-marshalling complicates things.
-
- # NOTE: This example uses Internet Explorer, but it should not be considerd
- # a "best-practices" for writing against IE events, but for working with
- # events in general. For example:
- # * The first OnDocumentComplete event is not a reliable indicator that the
- # URL has completed loading
- # * As we are demonstrating the most efficient way of handling events, when
- # running this sample you will see an IE Windows briefly appear, but
- # vanish without ever being repainted.
-
- import sys
-
- sys.coinit_flags = 0 # specify free threading
-
-
- import pythoncom
- import win32api
- import win32com.client
- import win32event
-
-
- # The print statements indicate that COM has actually started another thread
- # and will deliver the events to that thread (ie, the events do not actually
- # fire on our main thread.
- class ExplorerEvents:
- def __init__(self):
- # We reuse this event for all events.
- self.event = win32event.CreateEvent(None, 0, 0, None)
-
- def OnDocumentComplete(self, pDisp=pythoncom.Empty, URL=pythoncom.Empty):
- #
- # Caution: Since the main thread and events thread(s) are different
- # it may be necessary to serialize access to shared data. Because
- # this is a simple test case, that is not required here. Your
- # situation may be different. Caveat programmer.
- #
- thread = win32api.GetCurrentThreadId()
- print("OnDocumentComplete event processed on thread %d" % thread)
- # Set the event our main thread is waiting on.
- win32event.SetEvent(self.event)
-
- def OnQuit(self):
- thread = win32api.GetCurrentThreadId()
- print("OnQuit event processed on thread %d" % thread)
- win32event.SetEvent(self.event)
-
-
- def TestExplorerEvents():
- iexplore = win32com.client.DispatchWithEvents(
- "InternetExplorer.Application", ExplorerEvents
- )
-
- thread = win32api.GetCurrentThreadId()
- print("TestExplorerEvents created IE object on thread %d" % thread)
-
- iexplore.Visible = 1
- try:
- iexplore.Navigate(win32api.GetFullPathName("..\\readme.html"))
- except pythoncom.com_error as details:
- print("Warning - could not open the test HTML file", details)
-
- # In this free-threaded example, we can simply wait until an event has
- # been set - we will give it 2 seconds before giving up.
- rc = win32event.WaitForSingleObject(iexplore.event, 2000)
- if rc != win32event.WAIT_OBJECT_0:
- print("Document load event FAILED to fire!!!")
-
- iexplore.Quit()
- # Now we can do the same thing to wait for exit!
- # Although Quit generates events, in this free-threaded world we
- # do *not* need to run any message pumps.
-
- rc = win32event.WaitForSingleObject(iexplore.event, 2000)
- if rc != win32event.WAIT_OBJECT_0:
- print("OnQuit event FAILED to fire!!!")
-
- iexplore = None
- print("Finished the IE event sample!")
-
-
- if __name__ == "__main__":
- TestExplorerEvents()
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