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Re: Event Handler UPP question

On Tuesday, August 26, 2003, at 05:22 PM, Bob Sabiston wrote:

Hello,
I have a question about the way EventHandler UPP's work. In order to install an event handler, say to a window, you have to make a UPP for the handler function. Then you call InstallEventHandler to attach it to the window. Later, if you need to, you can remove the handler by using the Ref that is returned from the Install.

In my program, there is a point where I remove the handlers for a window, and I install different ones. This can happen several times during the program's running. My question:

Do the calls to NewEventHandlerUPP() reserve memory that I should be freeing? When should I free it? If the function that installs the handlers gets called many times, do I have a memory leak?

Yes you probably have a leak.

You only need one UPP for any callback. I use a static variable and do this:

{
static EventHandlerUPP handlerUPP = NewEventHandlerUPP(MyHandler);

verify_noerr(InstallApplicationEventHandler(handlerUPP, GetEventTypeCount(events), events, (void *) this, NULL));
}

That way only one UPP is ever created for MyHandler

I don't worry about freeing it as it'll go away when my app's address space is torn down.

Bryan
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 >Event Handler UPP question (From: Bob Sabiston <email@hidden>)



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