Re: [Pyobjc-dev] implementing objective C interface in python

[John S. <joh...@gm...>]

On Jan 31, 2008 3:43 AM, Ronald Oussoren <ron...@ma...> wrote:

>
> On 31 Jan, 2008, at 7:19, John Stoner wrote:
>
> in WiiRemoteDiscovery.h;
>
> @interface NSObject( WiiRemoteDiscoveryDelegate )
>
> - (void) WiiRemoteDiscovered:(WiiRemote*)wiimote;
> - (void) WiiRemoteDiscoveryError:(int)code;
>
> @end;
> in python;
>
>     wd = WiiRemoteDiscovery.new()
>     class wii_remote_discovery_delegate(WiiRemoteDiscoveryDelegate):
>         def wiiRemoteDiscovered_(self, wiiRemote):
>             self.wiiRemote=wiiRemote
>             print "discovered"
>         def WiiRemoteDiscoveryError_(self, returnCode):
>             print "not discovered"
>     x=wii_remote_discovery_delegate()
>     wd.setDelegate_(x)
>     wd.start()
>
> Traceback (most recent call last):
>   File "/Users/jstoner/Documents/projects/boogiepants/wii.py", line 29, in
> <module>
>     class wii_remote_discovery_delegate(WiiRemoteDiscoveryDelegate):
> NameError: name 'WiiRemoteDiscoveryDelegate' is not defined
> >>>
>
> Do I need to do a stub implementation of WiiRemoteDiscoveryDelegate or
> does PyObjC have a way to handle this?
>
>
> WiiRemoteDiscoveryDelegate is not a class, but a category (which is the
> ObjC way of adding new methods to an existingclass). You have to define an
> objc.informal_protocol that defines which methods are present in the
> WiiRemoteDiscoveryDelegate informal protocol (the category in the header
> file). You can then define your delegate as a subclass of NSObject, PyObjC
> will automaticly detect that you're implementing an informal protocol and
> use the right type information for your methods.
>
> This is a sample protocol definition from the Foundation wrappers in
> PyObjC 1.4:
>
> NSArchiverCallback = _objc.informal_protocol(
>     "NSArchiverCallback",
>     [
> # (Class)classForArchiver
>         _objc.selector(
>             None,
>             selector='classForArchiver',
>             signature='#@:',
>             isRequired=0,
>         ),
> # (id)replacementObjectForArchiver:(NSArchiver *)archiver
>         _objc.selector(
>             None,
>             selector='replacementObjectForArchiver:',
>             signature='@@:@',
>             isRequired=0,
>         ),
>     ]
> )
>
>
> The hardest part is defining the 'signature' strings, Apple's ADC website
> contains an Objective-C runtime manual that explains how to construct these
> strings.
>
> Ronald
>
>
>
>
Closer and closer:


    wd = WiiRemoteDiscovery.new()
    WiiRemoteDiscoveryDelegate = objc.informal_protocol(
        "WiiRemoteDiscoveryDelegate",
        [
            # (void) WiiRemoteDiscovered:(WiiRemote*)wiimote;
            objc.selector(
                None,
                selector='WiiRemoteDiscovered:',
                signature='v@:@',
                isRequired=0,
                ),
            # (void) WiiRemoteDiscoveryError:(int)code;
            objc.selector(
                None,
                selector='WiiRemoteDiscoveryError:',
                signature='v@:i',
                isRequired=0,
                ),
        ]
    )
    class wii_remote_discovery_delegate(NSObject):
        def wiiRemoteDiscovered_(self, wiiRemote):
            self.wiiRemote=wiiRemote
            print "discovered"
        def WiiRemoteDiscoveryError_(self, returnCode):
            print "not discovered"
    x=wii_remote_discovery_delegate.new()
    wd.setDelegate_(x)
    wd.start()

It still fails, but  silently this time. Is it the  'self' reference?

I tried to find that doc you mentioned... I think it has been relocated if
not deleted. There are a few pages that I found that refer to it, but have
links to the wrong page.


-- 
blog:
http://www.generosity.org/stoner/
'In knowledge is power, in  wisdom, humility.'