Hierarchy of iOS App UI - uiview

I am getting confused reading about CALayers, UIViews and View Controllers. Can someone explain the relationship each of those have to each other (and include anything I might have missed?).
I am particularly interested in a View that may have more than one layer. Does that mean the the View Controller has multiple UIViews or that the UIView has more than one CALayer? Or, does the UIView have another UIView subview?
Thanks for the help guys.
Edit: I guess I should have mentioned I am going to be setting these guys up programmatically, which is why I need to actually understand the relationships instead of relying on IB to do all the heavy lifting for me.

Have you read
http://tuvix.apple.com/library/ios/#documentation/Cocoa/Conceptual/CoreAnimation_guide/Articles/LayerTreeHierarchy.html ?

Related

Scroll View in SpriteKit

I want to make a vertical scrolling view for the level selector on my SpriteKit game, I don't know if I have to use UIScrollView or make it using the SpriteKit framework. Please if anyone knows the best way to do it and how let me know. Thanks.
You have several options here.
It is possible to integrate UI elements into SpriteKit, but instead of adding children to self (your scene), you would add subviews to self.view. You would of course, work with the view now instead of a scene so theres a different way of positioning elements which you would have to work out. Theres quite a few examples of how to do this, here's one that might help you.
An alternative is using something like Scroll Kit, which helps you integrate a UIScrollView into SpriteKit very conveniently!
Also check out this question which might be exactly what you're looking for. Hope this helps!

Storyboard connected properties not work

Im really confused because my problem may sound silly, i try to explain it clear - when i add anything on storyboard view controller it has no effect. And obvious, my viewController set properly to a controller, that manage storyboard scene. I adding anything - buttons, imageViews, it doesn't appear on a screen at all.
Also i want to add, i never seen such problem before recent Xcode update, when storyboard scene's become "large" and there is single scene for any device (600x600).
That issue literally drive me crazy, i can manage interface objects programmatically but i don't want to, because i use to work with Storyboard. Could you please write some advice or solution?
Thanks!
You need to add positioning constraints. By default, it will leave elements where they are, so they might be cut off. Also make sure what should be in the background is Sent to Back.
You can check if the auto layout this interfirindo or even if you this in the right view.

Who should manage the UI Elements, the view or the view controller?

I am currently developing an iOS app and I was wondering how to manage the UI elements. I am using a Storyboard to place my views and Autolayout to make everything resolution independent. If it helps, here's a bit of background on how I came up with this question.
Some Backgroud
I have buttons the represent piano keys and I later in code add a subview to these that draws the actual keys on them. I did this by creating #IBOutlets on the ViewController and susbscribed to the UIDeviceOrientationDidChangeNotification. This called a method that adds the subviews based on the current button frames to get the appropriate sized keys.
This worked fine when running in iOS 8.1, but if I ran the app on iOS 7, the frames of the buttons weren't updated to the new orientation by the time I got the UIDeviceOrientationDidChangeNotification, so everything was messed up in landscape. I did a little research (UIInterfaceOrientation not yet updated when UIDeviceOrientationDidChangeNotification caught in UIView) and it seems that a good solution would be to override the layoutSubviews method. Problem is, layoutSubviewsis a UIView method, and I am managing my buttons and UI in my UIViewController.
Impulsively I wanted to subclass my UIView, override layoutSubviews and from there call a method on my Controller to add the keys to the buttons correctly, but that doesn't sound right.
The Questions
My UI is managed by the UIViewController. But I need to update my views based on a method proper of a UIView. I assume, to respect the MVC principles, that my view should't now a thing about my controller, but then this brings up a few questions:
Who should be managing the UI?
Is my strategy wrong and should the
UIView hold the #IBOutlets to the buttons so that it can later
apply the subviews I need them to have?
If you read the background, do you have a suggestion for this particular situation?
I assume the complexity of this problem is relatively small and I don't need to setup notifications in NSNotificationCenter, but I may be wrong. I would really like to hear this is not the only solution.
Thanks in advance. I hope I was clear enough, but if you want/need any additional details on my particular situation, let me know and I will gladly elaborate.
if I understood the question correctly, your ViewController should be laying out the keys within it's view. A good, but not the only, place to do this is in viewDidLayoutSubviews which a method you can override on UIViewController.
Now if your views should maintain their internal layout. i.e if you buttons/keys have any subviews, you should update those in layoutSubviews on UIView as you mentioned.
Both methods will be called in response to changes in the bounds or center of your parent view.
As far as rotation changes are concerned, in iOS 8, you should use viewWillTransitionToSize:withTransitionCoordinator: or willTransitionToTraitCollection:withTransitionCoordinator:
depending on your needs.
I highly recommend that you write your layout independent of orientation. You should just use the containing view's bounds for reference and never hard code in any frames. For example perhaps one of your keys should be 1/56 the width of it's superview instead of a magical number for portrait and landscape.

One view is always drawn in front of all the other views/layers in iOS

I have a custom UIView and I have many views in my hierarchy. Whatever I do, my custom view is always in front of all the others when I run on iOS 7. There is no problem in iOS 8 though. In IB, the view is far behind my other views. Is there any way to override this behavior? I've tried incrementing one of the views' layer's zPosition but it didn't change anything. Why can this happen?
I've ended up using bringSubviewToFront: method of UIView and it worked. I still have no idea why it was displaying at the wrong order though. I'm accepting my answer as it solved my problem, but any recommendations on why it happened is welcome.

Custom Scroll view in cocos2d without using uikit

I currently need to create a custom scroll view without using UIKit's scrollview in cocos2d.
The best way, I think, is to create a separate layer and then add all my sprites to that layer. But I'm not sure how to receive touch events for all of the sprites. Is there a best way to do this? Thanks!
Have you seen CCScrollLayer? It might not be suitable for you but maybe you can copy the way that it is picking up touches.
https://github.com/cocos2d/cocos2d-iphone-extensions/tree/develop/Extensions/CCScrollLayer
http://www.cocos2d-iphone.org/forum/topic/17118
There's another one here as well, not sure if it's a fork or an independent one:
https://github.com/jerrodputman/CCKit
But I didn't have much success with any of these. The bounce and other parts of the experience never feel right, so I go back to using UIScrollView to handle the touches.
I've been facing the same issue and I found the SWScrollView here:
https://github.com/saim80/Cocos2D-Extensions
met my needs better than CCScrollView. It acts more like the UIScrollView where as CCScrollView is more for paging from what I've seen.
There is a nice framework called CMMSimpleFramework.
http://www.cocos2d-iphone.org/forum/topic/39018
http://www.cocos2d-iphone.org/forum/topic/60354
There are some sample videos, and the link to the repo is on those pages.
One of the classes is a scrolling layer that might do what you need.
To get the sample project to run, I had to comment out some game center authentication handler code that has changed, but after I did that the demo worked fine.

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