At least I know to look out for (void *) and pass objects around outside them.
Thx for the help. On Wed, Dec 31, 2008 at 2:08 PM, Laurent Sansonetti <lsansone...@apple.com> wrote: > Oh I see, indeed. The problem here is that the contextInfo argument has a > "void *" type, so the runtime does not know that you passed an Objective-C > object for it via an implicit cast. > > In this case, we need to introduce a new method on Pointer to allow you to > change its type. In RubyCocoa, the method is #cast_as, I will probably use > the same name. > > In practice, you should avoid passing objects as context to methods like > this one, because their implementation won't keep a GC reference to them, so > they might disappear during a collection cycle. > > Laurent > > On Dec 30, 2008, at 7:52 PM, Nic Williams wrote: > >> Calling recipe[0] results in this error: >> >> AppDelegate.rb:157:in `[]': can't convert C/Objective-C value >> `0x8004676a0' of type `v' to Ruby object (ArgumentError) >> >> I'm not sure what this means. I've played around with the Pointer >> class and I can get this error a lot. >> >> The original ObjC signature that is called to open the NSOpenPanel is: >> >> - (void)beginSheetForDirectory:(NSString *)path file:(NSString *)name >> modalForWindow:(NSWindow *)docWindow modalDelegate:(id)modalDelegate >> didEndSelector:(SEL)didEndSelector contextInfo:(void *)contextInfo >> >> Where the recipe (NSManagedObject_Recipe) is passed into a (void >> *)contextInfo. Do I need to do anything fancy for this? Is the (void >> *) causing the Pointer creation? >> >> On Wed, Dec 31, 2008 at 1:46 PM, Laurent Sansonetti >> <lsansone...@apple.com> wrote: >>> >>> On Dec 30, 2008, at 7:32 PM, Nic Williams wrote: >>> >>>> In this code sample: http://gist.github.com/41855 I am getting a >>>> Pointer instance instead of an NSManagedObject_Recipe instance (from >>>> Core Data). Subsequently the setValue:forKey: call at the end of the >>>> delegate/callback method fails. >>>> >>>> The top method addImage(sender) launches an NSOpenPanel, which >>>> delegates to the second/last method >>>> addImageSheetDidEnd:returnCode:contextInfo: when the panel is closed. >>>> >>>> But instead of passing through the NSManagedObject_Recipe instance to >>>> the contextInfo: recipe value, I am getting a Pointer. >>>> >>>> Is this correct? Or how do I get my NSManagedObject_Recipe instance >>>> from the Pointer. MacRuby src for Pointer class doesn't suggest it has >>>> any methods for getting the pointed-to thing. >>>> >>>> rb_cPointer = rb_define_class("Pointer", rb_cObject); >>>> rb_undef_alloc_func(rb_cPointer); >>>> rb_define_singleton_method(rb_cPointer, "new_with_type", >>>> rb_pointer_new_with_type, 1); >>>> rb_define_method(rb_cPointer, "assign", rb_pointer_assign, 1); >>>> rb_define_method(rb_cPointer, "[]", rb_pointer_aref, 1); >>> >>> You can do pointer[0] to dereference it. >>> >>> A Pointer object can be created from a C array of elements, which is why >>> Pointer responds to #[] (so that you can dereference a particular slot). >>> >>> Laurent >>> _______________________________________________ >>> MacRuby-devel mailing list >>> MacRuby-devel@lists.macosforge.org >>> http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel >>> >> >> >> >> -- >> Dr Nic Williams >> iPhone and Rails consultants - http://mocra.com >> Fun with iPhone/Ruby/Rails/Javascript - http://drnicwilliams.com >> * Surf Report for iPhone - http://mocra.com/projects/surfreport/ * >> _______________________________________________ >> MacRuby-devel mailing list >> MacRuby-devel@lists.macosforge.org >> http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel > > _______________________________________________ > MacRuby-devel mailing list > MacRuby-devel@lists.macosforge.org > http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel > -- Dr Nic Williams iPhone and Rails consultants - http://mocra.com Fun with iPhone/Ruby/Rails/Javascript - http://drnicwilliams.com * Surf Report for iPhone - http://mocra.com/projects/surfreport/ * _______________________________________________ MacRuby-devel mailing list MacRuby-devel@lists.macosforge.org http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel
