Subscribing Events with Inherited classes

[Kevin]

Hello,

I have a class NurikabeGUI, which inherits from BoardGUI. Inside BoardGUI I have the function:

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bool BoardGUI::checkClicked(const CEGUI::EventArgs& args)
{
    ...
    return true;
}

I am trying to subscribe a button to this callback in the NurikabeGUI constructor. I first tried:

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_checkButton->subscribeEvent(CEGUI::PushButton::EventClicked, CEGUI::Event::Subscriber(&BoardGUI::checkClicked, this));


which gives me the errors:

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c:\Progs\PencilPuzzles\NurikabeGUI.cpp(24): error C2248: 'Penpa::BoardGUI::checkClicked' : cannot access protected member declared in class 'Penpa::BoardGUI'

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c:\Progs\PencilPuzzles\NurikabeGUI.cpp(24): error C2661: 'CEGUI::SubscriberSlot::SubscriberSlot' : no overloaded function takes 2 arguments

I then tried

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_checkButton->subscribeEvent(CEGUI::PushButton::EventClicked, CEGUI::Event::Subscriber(&NurikabeGUI::checkClicked, this));


since 'this' is an instance of NurikabeGUI. In this case, I get the second error as above, but not the first.

So I suppose my question is this: Is it possible to use an inherited function as a callback?

Thanks in advance!
Kevin

[Jamarr]

So I suppose my question is this: Is it possible to use an inherited function as a callback?

Yes, of course.

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c:\Progs\PencilPuzzles\NurikabeGUI.cpp(24): error C2661: 'CEGUI::SubscriberSlot::SubscriberSlot' : no overloaded function takes 2 arguments

This means your code is not written correctly. You probably messed up the decleration or something. If you search the forum for "no overloaded function takes arguments" (note I left out the '2' - it messes up the results page) every single one of those posts end up being syntax related.

[Kevin]

Hello,

Thanks for the reply, but I don't think that is the problem. I have successfully subscribed to many events before with no problems. The difference with this one is that the function I am trying to subscribe to is not declared in the class itself, but a class it inherits from, which seems to be what it's complaining about.

Kevin

[Kevin]

Just an update:

I tried cut-and-pasting the function exactly as it was from the base class (BoardGUI) to the derived class (NurikabeGUI), and now it works fine, so the problem is definitely to do with the fact that it's an inherited function.

[Jamarr]

Yes, I see. I missread your initial post. I thought you had already redefined the method in the derived class.

It is odd, because the CEGUI::SubscriberSlot class already has a templated constructor for class methods. For some reason the compiler is not recognizing inherited class methods as valid template parameters for that constructor.

You can still work around the issue by explicitly using the FunctorReference constructor instead, like so:

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_checkButton->subscribeEvent(CEGUI::PushButton::EventClicked, CEGUI::Event::Subscriber(CEGUI::MemberFunctionSlot<NurikabeGUI>(&NurikabeGUI::checkClicked, this)));