Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!stl!siesoft!davidto
From: davidto@siesoft.co.uk (David Tollow)
Newsgroups: comp.windows.x
Subject: ClientMessage to root window
Summary: can I use the root window as an anonymous mailbox
Keywords: ClientMessage root SelectInput
Message-ID: <1991Mar13.083845.1313@siesoft.co.uk>
Date: 13 Mar 91 08:38:45 GMT
Sender: usenet@siesoft.co.uk (NNTP Poster)
Distribution: comp.windows.x
Organization: Siemens-Nixdorf Systems Development Group, UK
Lines: 27

In the course of working on a (highly non-standard) drag-and-drop
scheme I came across what seems to me a paradox associated with
ClientMessages.

ClientMessages are always selected on all windows, so there is no
event mask associated with them. However if I don't know a window
id belonging to the intended recipient of the message then I 
can't send it.

What I can do is send a client message to the root window and have
the receiving client select for client messages on root, but I can't
because there isn't an event mask for ClientMessage...

Actually I can overcome this problem by associating a property with
the root window and having the sender change it. The recipient who
has selected the PropertyChangeMask then receives PropertyNotify events
with the embedded data.

So, accepting that what I am doing is potentially bad practice
and counter to all standards, can someone explain the philosophy
behind the asymmetry between ClientMessage and other event types ?

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davidto@siesoft.co.uk			Siemens Nixdorf
					Bracknell
					UK