Re: [boost] Re: Re: Java style GUI in C++

From: John Torjo (john.lists_at_[hidden])
Date: 2004-08-23 03:02:45

> 
> 
> The problem with the "registering your self in a slot" approach, is that most events generate actions -> ie they application flow is bi-directional.  The signal/slot approach (usually) suffers from not being able to send a response back to the event sender.
> 

I think there's a bigger problem here - with boost::signal.
When handling some events, in a certain handler - you might find 
yourself wanting to turn off further processing of events.

Imagine this case:
You might want to turn off commands (like, "File Save", "Undo", "Redo", 
etc.) which come from accelerators (key-stokes).
In such a case, you'd like to register your event handler to handle 
commands first.
Then, see if a command is enabled. If so, allow other handlers to handle 
it. If it's disabled, turn off further handling.

Correct me if I'm wrong, but I don't think that's possible with 
boost::signal.

Best,
John

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