Re: [Pyobjc-dev] handle function calls with struct arguments?

[Ronald O. <ron...@ma...>]

On 27 Jan, 2008, at 5:01, Ian Johnson wrote:

> I am trying to use a framework with some delegate functions that  
> pass structs in the call:
>
> - (void) buttonChanged:(WiiButtonType) type isPressed:(BOOL)  
> isPressed;
>
> when I try to make this python function:
> def buttonChanged_isPressed_(self, type, isPressed):
> I get an error around pythonify_c_value
>
> if I change it to:
> def buttonChanged_isPressed_(self, *posargs, **kwdargs):
>         print posargs
>         print kwdargs
>
> the output is () and {}
>
> Does pyobjc not support structs in function calls?

PyObjC supports structs in method and function calls just fine, but  
someone has to tell it that a struct is involved. You're actually  
lucky that you didn't get a crash :-).

You have to define your callback like this:

    def buttonChanged_isPressed_(self, type, isPressed):
        pass
    buttonChanged_isPressed_ = objc.selector(buttonChanged_isPressed_,  
type="v@:ic")

That is, you have to tell the bridge the types of your argument  
because the bridge has no information that tells it that the type  
isn't "NSObject*".

If you plan to use this library more you can create a wrapper module  
that allows you to just "import WiiRemote", you can then define an  
objc.informal_protocol in that module that contains the method names  
and signatures for the delegate callbacks.

Ronald
>
>
> here is my code in case anyone is interested:
> http://enja.org/enj/enjapen/enjapenAppDelegate.py
>
> and here is the library I am trying to use:
> http://darwiin-remote.svn.sourceforge.net/viewvc/darwiin-remote/WiiRemoteFramework/trunk/WiiRemote.h?view=markup
>
> -- 
> Ian Johnson
>
> Ignorance is Piss.  
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