[Pythonmac-SIG] Using UKKQueue with PyObjC

[Bob Ippolito]

On Mar 8, 2005, at 10:54, Florian Munz wrote:

> Bob Ippolito <bob at redivi.com> wrote:
>
>> It's automatically generated from the Xcode project and is a 
>> relatively
>> general solution, so it's not minimal.  Works fine with --alias here,
>> you should try it with py2app svn trunk.
>
> Okay, since I'm am not using XCode I thought there must be a simpler
> way.

There is, but not much simpler.  You still have to build an extension 
that the Objective-C code is going to live in.  If it was a pre-built 
framework or plug-in it would be a different story, but compiling one 
of those is harder than having distutils build an extension.

>> You probably can use any Python class, but the most well tested
>> solution is to use a NSObject subclass whenever you have code that is
>> going to be called from Objective-C, so I would recommend doing that.
>
> I tried subclassing NSObject but now I am not sure about the right way
> to create an object. Take this minimal example:
>
> class Converter (NSObject):
>    def init(self):
>       self = NSObject.init(self)
>       NSWorkspace.sharedWorkspace().notificationCenter().
> addObserver_selector_name_object_(
>          self, "documentChanged:",
>          None,
>          None)
>       return self
>
>    def documentChanged_(self, notification):
>       print 'handleChange'
>
> If I instantiate this class from the Main-Class with
> Converter.alloc().init() my application dies quickly (Crash Reporter,
> nothing in the logs). If I however instantiate it from Interface 
> Builder
> it works. Is this a bug or a feature? :)
> I don't want to instantate it from IB, because I have 4 of these 
> classes
> and don't need all of them everytime.

You forgot to specify WHICH notification in Converter.. you're saying 
"add my documentChanged: selector as an observer to... nothing".

Also, use self = super(Converter, self).init()

-bob