How to return a primitive property value with CALayer's "+ (id) defaultValueForKey", etc?

Question

So.. CALayer KVC "extensions" handle all the weirdo's... such as..

+ (id) defaultValueForKey: (NSString*)key    {
   return [key isEqualToString:@"borderColor"] 
        ? (id)cgPINK 
        : [super defaultValueForKey:key];    }

And Apple's Docs allude to how best to encode a struct, when they refer to the default value if you DON'T provide a value...

For example, if the value for key is a CGSize struct, the method returns a size struct containing (0.0,0.0) wrapped in an NSValue object.

However, I can't figure out how to provide normal, stinking, primitives, i.e. CGFloat

I've tried @VAL-type NSNumber encoding,

~~return ![key isEqualToString:@"lineWidth"] ?: @3;~~

and with no viable NSValue methods, even a desperate attempt to cast them to id

~~return ![key isEqualToString:@"zPosition"] ?: (id)262453;~~// lol

What's the deal? Is this just an "oh-well, ya can't" situation due to CALayer's odd-ball nature? An obvious solution I have embarrassingly overlooked? Or is it just a shady API - that refuses to document it's own shortcomings?

Does NSNumber numberWithFloat: or numberWithInt not work? – combinatorial Nov 18 '12 at 07:20 — combinatorial, Nov 18 '12 at 07:20

score 0 · Answer 1 · answered Nov 18 '12 at 15:12

You should be able to return an NSNumber.

I haven't yet tried using Objective C literals. Skip that for now to limit the complications. Just use code like this:

return [NSNumber numberWithFloat: 3.0];

or numberWithBool, or numberWithInt, or whatever is appropriate.

How to return a primitive property value with CALayer's "+ (id) defaultValueForKey", etc?

1 Answers1