How can I get notified when NSViewController instance is loaded / unloaded

Question

On iOS, there are viewDidAppear / viewDidDisappear methods. They are also being added to Yosemite (see https://developer.apple.com/library/prerelease/mac/releasenotes/AppKit/RN-AppKit/#10_10ViewController).

Question: how can I detect when my view is appearing / disappearing pre-OS X 10.10?

Just an idea: perhaps there's some room for overriding `addSubview:` etc. in a subclass...? I'm guessing the `superview` property is readonly, so intercepting `setSuperview:` is not possible... — Nicolas Miari, Aug 19 '14 at 01:40

meda · Answer 1 · 2014-08-19T03:21:10.740

-1

You can use loadView

- (void)loadView {
    [super loadView];

}

I don't know your goal but if you really needed it. There was viewDidUnload and viewWillUnload but Apple deprecated them and warned people that they are being misused.

The cost of releasing objects when the view unload is not expensive so they just got rid of it.

edited Aug 19 '14 at 03:21

answered Aug 19 '14 at 02:01

meda

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`loadView` can address the activation bit. Any ideas for deactivation? – Michael Teper Aug 19 '14 at 02:17
It seems the `viewDidUnload` was available on iOS, as a quick Google search isn't showing anything specifically for OS X. – MaddTheSane Jan 05 '15 at 05:03
loadView is for controllers that load their view programmatically (i.e., not from a nib or storyboard). viewDidAppear and viewDidDissappear are what you want. – wcochran May 23 '17 at 23:42
@wcochran so you downvote me instead of pozting your answer – meda May 24 '17 at 01:02

score -1 · Answer 2 · answered Jan 05 '15 at 05:17

-1

The only way I can see pre-Yosemite systems using something similar to viewDidDisappear is to subclass NSView and overriding viewDidHide to call a delegate class.

Or you could do some method swizzling on the NSView class on pre-Yosemite systems.

answered Jan 05 '15 at 05:17

MaddTheSane

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How can I get notified when NSViewController instance is loaded / unloaded

2 Answers2