On Mar 25, 2011, at 6:22 PM, Quincey Morris wrote:

> On Mar 25, 2011, at 18:01, Rick Mann wrote:
> 
>> Part of the problem I had was that I don't have indices readily available. I 
>> have the objects themselves, and I could look them up in the array, but that 
>> strikes me as potentially slow (for a lot of objects).
> 
> There's always -[NSArrayController setSelectedObjects], though using that 
> might just drive the work involved in deriving selection indexes inside 
> NSArrayController, where you can't even control the performance.
> 
> But the point is that the underlying mechanism is all in NSArrayController's 
> documented API, and you should be reading that.

OK. Truth is, there are so many slightly different ways to get & set the 
selection in object controllers, and while I've been able to mimic examples to 
get things to work, I really don't understand them well, despite having read 
the docs. Frankly, I think the docs are inadequate. Could be because of 
assumptions I'm implicitly making about how I'd expect them to behave.

But with what you've told me, now I know what to at least try to do.

> 
>> I think there's a typo there, so I'm not quite sure what you're telling me. 
>> In fact, I will eventually have both a custom control in the inspector, and 
>> the view in which the selection is managed by the user is custom.
> 
> Yes, it was a typo. I meant:
> 
>> "you aren't going to want to do this with bindings, not when the selection 
>> is controlled from a custom view"
> 
> For a custom view, that is, where the behavior of the view is enshrined in 
> code you write, there's absolutely no value in using bindings, and creating a 
> bindings mechanism for that view is wasted work.
> 
> Bindings are for UI elements (and similar stuff) that are reused in many 
> contexts, so that they can be configurable in IB without additional coding. 
> Your custom view is being used in one context (presumably, more or less), and 
> you're coding its behavior anyway.
> 
> Putting this another way, bindings are (in use) a kind of code-free extension 
> of the KVO mechanism (addObserver... and observeValue...). If you're coding 
> anyway, it's cheaper and easier to use KVO directly.
> 
> That was the point I was trying to make.

Gotcha. Well, in this case, my inspectors are made up of many different 
standard widgets, and for them I really do want to use bindings. Moreover, the 
objects that might be selected can be provided by plug-ins to my app. But I get 
what you're saying, and my custom control may not merit bindings of its own.

Thanks!



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