Spurious web browser events

From: Rick Aldred (rick.aldred_at_wincor-nixdorf.com)
Date: 06/18/04 

Date: Fri, 18 Jun 2004 04:17:41 -0700

Hi,

I am hosting a web browser control in a VC .NET C++ Kiosk
application using the MFC wrapper to ActiveX.

We have developed a mechanism for the web server to be
able to send commands to our client application by
changing the title of the current web page. This fine as
we are displaying the web content in full screen mode.

To do this we are sinking the DISPID_TITLECHANGE event.

There are two main commands which we react depending on
the new title: 'Print' and 'Request the status of the
printer hardware'. The Print jobs are issued one at a
time, but the request status command can be issued at any
time (even during printing). A print job typically takes
10 seconds, whereas a request status command is relatively
quick (< 1 sec). Both commands are initiated synchronously
through our OnTitleChange event handler method.

The strange behaviour we are seeing is that if we receive
a request status title command whilst a print command is
in progress, we then receive additional spurious title
change events (all requesting the printer status). We know
for sure that these extra events are not being initiated
by the web server changing the title of the page, and so
we have drawn a blank as to what could be causing this.

Maybe it is because the print title change event is not
being handled quick enough by our application which causes
MSHTML to resend the request status events multiple times?

Has anyone else seen this behaviour and are there any
suggested solutions?

Many thanks,
Rick

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