Adding constraints programmatically to IB Scene - ios

Question

I'm trying to add a subview and some constraints to a scene, which is build using the interface builder.
The subview gets added correctly, but when I try to add the constraints the app crashes with the following error, which implies that I've got the view hierarchy mixed up. However I'm can't find my error.
Shopigator[14377:635114] The view hierarchy is not prepared for the constraint: <NSLayoutConstraint:0x7fafab4bb660 THSegmentedControl:0x7fafaf03a6e0.centerX == UISearchBar:0x7fafaf0334b0.centerX>
When added to a view, the constraint's items must be descendants of that view (or the view itself). This will crash if the constraint needs to be resolved before the view hierarchy is assembled. Break on -[UIView _viewHierarchyUnpreparedForConstraint:] to debug.
2015-03-13 11:51:12.004 Shopigator[14377:635114] View hierarchy unprepared for constraint.
Constraint: <NSLayoutConstraint:0x7fafab4bb660 THSegmentedControl:0x7fafaf03a6e0.centerX == UISearchBar:0x7fafaf0334b0.centerX>
Container hierarchy:
<UIView: 0x7fafaf037d70; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7fafab424a00>>
| <_UILayoutGuide: 0x7fafaf037e40; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7fafa97e4710>>
| <_UILayoutGuide: 0x7fafaf037540; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7fafaf0ed980>>
| <UIView: 0x7fafaf035e40; frame = (0 0; 500 50); layer = <CALayer: 0x7fafaf0a9be0>>
| <THSegmentedControl: 0x7fafaf03a6e0; baseClass = UIControl; frame = (34 297; 332 29); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x7fafaf0398d0>>
View not found in container hierarchy: <UISearchBar: 0x7fafaf0334b0; frame = (0 0; 320 44); text = ''; opaque = NO; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7fafb10ad1f0>; layer = <CALayer: 0x7fafab44ed10>>
That view's superview: NO SUPERVIEW
2015-03-13 11:51:12.060 Shopigator[14377:635114] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Unable to install constraint on view. Does the constraint reference something from outside the subtree of the view? That's illegal. constraint:<NSLayoutConstraint:0x7fafab4bb660 THSegmentedControl:0x7fafaf03a6e0.centerX == UISearchBar:0x7fafaf0334b0.centerX> view:<UIView: 0x7fafaf037d70; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7fafab424a00>>'
*** First throw call stack:
(
0 CoreFoundation 0x0000000108a2df35 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x00000001086c6bb7 objc_exception_throw + 45
2 CoreFoundation 0x0000000108a2de6d +[NSException raise:format:] + 205
3 Foundation 0x0000000107f6e0f9 -[NSLayoutConstraint _addToEngine:integralizationAdjustment:mutuallyExclusiveConstraints:] + 187
4 UIKit 0x0000000109b77de5 __57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke_2 + 474
5 Foundation 0x0000000107f7bd6e -[NSISEngine withBehaviors:performModifications:] + 155
6 UIKit 0x0000000109b77beb __57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke + 452
7 UIKit 0x0000000109b779fe -[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:] + 197
8 UIKit 0x0000000109b77671 -[UIView(AdditionalLayoutSupport) _initializeHostedLayoutEngine] + 404
9 UIKit 0x0000000109b78191 -[UIView(AdditionalLayoutSupport) _layoutEngineCreateIfNecessary] + 53
10 UIKit 0x0000000109b6cb0a -[UIView(UIConstraintBasedLayout) _layoutEngine_didAddLayoutConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 156
11 UIKit 0x0000000109b6cea4 -[UIView(UIConstraintBasedLayout) _tryToAddConstraintWithoutUpdatingConstraintsArray:roundingAdjustment:mutuallyExclusiveConstraints:] + 30
12 UIKit 0x0000000109b6cfcc -[UIView(UIConstraintBasedLayout) _tryToAddConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 243
13 Shopigator 0x0000000107507617 _TFC10Shopigator20FilterViewController11viewDidLoadfS0_FT_T_ + 9623
14 Shopigator 0x0000000107508d92 _TToFC10Shopigator20FilterViewController11viewDidLoadfS0_FT_T_ + 34
15 UIKit 0x0000000109617a90 -[UIViewController loadViewIfRequired] + 738
16 UIKit 0x0000000109617c8e -[UIViewController view] + 27
17 UIKit 0x0000000109bb941e -[_UIFullscreenPresentationController _setPresentedViewController:] + 65
18 UIKit 0x00000001095f3429 -[UIPresentationController initWithPresentedViewController:presentingViewController:] + 105
19 UIKit 0x0000000109623a41 -[UIViewController _presentViewController:withAnimationController:completion:] + 1746
20 UIKit 0x0000000109625d81 __62-[UIViewController presentViewController:animated:completion:]_block_invoke + 132
21 UIKit 0x0000000109625ca5 -[UIViewController presentViewController:animated:completion:] + 229
22 UIKit 0x00000001094f38be -[UIApplication sendAction:to:from:forEvent:] + 75
23 UIKit 0x00000001095fa410 -[UIControl _sendActionsForEvents:withEvent:] + 467
24 UIKit 0x00000001095f97df -[UIControl touchesEnded:withEvent:] + 522
25 UIKit 0x0000000109539308 -[UIWindow _sendTouchesForEvent:] + 735
26 UIKit 0x0000000109539c33 -[UIWindow sendEvent:] + 683
27 UIKit 0x00000001095069b1 -[UIApplication sendEvent:] + 246
28 UIKit 0x0000000109513a7d _UIApplicationHandleEventFromQueueEvent + 17370
29 UIKit 0x00000001094ef103 _UIApplicationHandleEventQueue + 1961
30 CoreFoundation 0x0000000108963551 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
31 CoreFoundation 0x000000010895941d __CFRunLoopDoSources0 + 269
32 CoreFoundation 0x0000000108958a54 __CFRunLoopRun + 868
33 CoreFoundation 0x0000000108958486 CFRunLoopRunSpecific + 470
34 GraphicsServices 0x000000010b2849f0 GSEventRunModal + 161
35 UIKit 0x00000001094f2420 UIApplicationMain + 1282
36 Shopigator 0x000000010748081e top_level_code + 78
37 Shopigator 0x000000010748085a main + 42
38 libdyld.dylib 0x000000010b7a8145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
Relevant parts of my ViewController
#IBOutlet weak var searchBar: UISearchBar!
#IBOutlet weak var radiusSlider: LoagarithmicSlider!
var priceClassSelector: THSegmentedControl?
override func viewDidLoad() {
super.viewDidLoad()
var pCFrame = CGRectMake(34, 297, 332, 29)
self.priceClassSelector = THSegmentedControl(segments: SearchFilter.PRICE_CLASS_LABELS)
self.priceClassSelector!.frame = pCFrame
self.priceClassSelector?.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addSubview(self.priceClassSelector!)
self.view.addConstraint(NSLayoutConstraint(
item: self.priceClassSelector!,
attribute: NSLayoutAttribute.CenterX,
relatedBy: NSLayoutRelation.Equal,
toItem: self.searchBar,
attribute: NSLayoutAttribute.CenterX,
multiplier: 1.0,
constant: 0))
}
And the view hierarchy in IB