new Event parameters

[spannerman]

Hi Eddie,

I posted this question in the wrong forum at one point, so you may have seen it briefly, but here it is again.

I am upgrading my application to use the new event subscription technique...I have been holding off doing it for a while but Ive heard that the new way yields better performance. It's all going well, but I have a few lines that I cant get to compile anymore, and these concern the passing of some extra parameters to my method which handles the event.

So, for example, I used to use this line of code which subscribed an event and in addition passed the String "Basic" through to my handlePanelShown method:

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myPanel->subscribeEvent( StaticText::EventShown,boost::bind(&MyWindow::handlePanelShown, this, _1, "Basic") );

The new way which does away with boost and uses the Subscriber probably should look something like this:

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myPanel->subscribeEvent( StaticText::EventShown,Event::Subscriber(&MyWindow::handlePanelShown, this,  "Basic") );

except this no longer compiles. The error says I am passing the wrong number of arguments, but my handlePanelShown method has not changed.

Any ideas what I might be doing wrong?

[nfz]

I know I am not CE but I'll make a stab at this since I started you on the change and I suspected this would cause a headache for you.

Event::Subscriber template does not support user definable number of arguments like boost::bind does. I think you have two alternatives. The first one is to change your design a bit and pass those user defined arguments by some other means or setup some state machines. The second option is to continue using boost::bind for those methods that take more arguments than the Event::Subscriber does and live with the overhead for those few methods that use it.

[spannerman]

Aah, ok, Cheers nfz. I dont fancy going back to boost so I'll get some alternative going instead. Like you said, not too many methods are affected so shouldnt be too bad.

[CrazyEddie]

Hi,

These would have been my suggestions too

The approach I would take would probably be to code a template functor class that could accept additional parameters (or something of that nature).

CE.