Re: Setting the selection of an array controller?
Re: Setting the selection of an array controller?
- Subject: Re: Setting the selection of an array controller?
- From: Rick Mann <email@hidden>
- Date: Fri, 25 Mar 2011 18:34:18 -0700
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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