On Aug 3, 2014, at 3:35 PM, Jens Alfke <[email protected]> wrote:
> On Aug 3, 2014, at 11:56 AM, Daryle Walker <[email protected]> wrote:
>>
>> I just noticed that myself. Is “(NSSegmentedControl
>> *)self.toolbarBackForward.view”, a cast to a (2 layers down) subclass, the
>> way you’re supposed to access the control’s stuff? It looks like a hack,
>> but I’ll take it since it (seemingly) works.
>
> Sure. Why is casting to a subclass a hack? It’s a fact of life in a
> statically-typed language. (You’re implicitly casting to subclasses all the
> time, like whenever you access objects in a collection; it’s just that the
> ‘id’ type saves you the trouble of explicitly having to write the cast. If
> anything, in this case it’s actually a safer cast since you know the object
> is a view, whereas with id it could be anything at all.)
It’s my understanding of Objective-C. I thought you could do:
[self.toolbarBackForward.view methodOfNSSegmentedControl:blah-blah-blah]
without complaint. I know that NSView doesn’t have that method, but the actual
object taking this at runtime is a subclass that does have the desired method.
I thought the compiler will ignore that fact with a warning instead of an
error. Is this something reserved only when using “id” as the static-time
pointer type? Am I misremembering seeing Objective-C code that lets this sort
of stuff through at compile-time because of saving it for run-time?
—
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT mac DOT com
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