The easiest way how to find unsatisfiable constraints: set unique identifier for every constraint in your view: create simple extension for NSLayoutConstraint: SWIFT: extension NSLayoutConstraint { override public var description: String { let id = identifier ?? “” return “id: \(id), constant: \(constant)” //you may print whatever you want here } } OBJECTIVE-C @interface NSLayoutConstraint … Read more
I had the same problem where I wanted my button to grow along with its title. I had to sublcass the UIButton and its intrinsicContentSize so that it returns the intrinsic size of the label. – (CGSize)intrinsicContentSize { return self.titleLabel.intrinsicContentSize; } Since the UILabel is multiline, its intrinsicContentSize is unknown and you have to set … Read more
add the following function to your view controller class… Swift 3 override func viewDidLayoutSubviews() { self.mainTextView.setContentOffset(.zero, animated: false) } Swift 2.1 override func viewDidLayoutSubviews() { self.mainTextView.setContentOffset(CGPointZero, animated: false) } Objective C – (void)viewDidLayoutSubviews { [self.mainTextView setContentOffset:CGPointZero animated:NO]; }
There’s an answer this question on objc.io in the “Intrinsic Content Size of Multi-Line Text” section of Advanced Auto Layout Toolbox. Here’s the relevant info: The intrinsic content size of UILabel and NSTextField is ambiguous for multi-line text. The height of the text depends on the width of the lines, which is yet to be … Read more
None of the posted answers solved the problem for me. But the reason for this is the following: Xcode 6 creates constraints based on relative margins by default. Those are only available on iOS 8.0 and newer. You get these warnings when your deployment target is set to iOS 7.0 or lower. The way I … Read more
Currently, no, it doesn’t look like it is possible to center a view in the superview using only VFL. It is, however, not that difficult to do it using a single VFL string and a single extra constraint (per axis): VFL: “|-(>=20)-[view]-(>=20)-|” [NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:view.superview attribute:NSLayoutAttributeCenterX multiplier:1.f constant:0.f]; One would think that you … Read more
Edit: I don’t recommend this anymore. This approach doesn’t scale well when new devices come out. Use a combination of dynamic font sizes and size classes-specific fonts. Say a new iPhone model comes out, if you are using Auto Layout and Size Classes you don’t have to fix all the constraints manually to make your … Read more
With AutoLayout enabled, we should FORGET FRAMES and only CONSIDER CONSTRAINTS.Yes, for animating also you can no longer change the frame or center, view’s will revert back to their original position when layout is called. Instead you should consider changing the constant value of the constraint to get the same effect. Consider a User Interface … Read more
You need to tell your BannerContainer view controller that it has a new child controller, and to tell the Child that it has a parent VC. This is described in the Apple Docs here. Like this: [self addChildViewController:vc]; vc.view.frame = CGRectMake(0, 0, self.container.frame.size.width, self.container.frame.size.height); [self.container addSubview:vc.view]; [vc didMoveToParentViewController:self]; Or in Swift: self.addChildViewController(vc) vc.view.frame = CGRectMake(0, … Read more
@robmayoff has a great answer for this: https://stackoverflow.com/a/26066992/1424669 Essentially, in iOS8 you can no longer call setNeedsUpdateConstraints and setNeedsLayout on a view and expect the constraints of subviews to update. You must call these methods on the view whose constraint is changing. This is backwards compatible to iOS7. EXAMPLE: Suppose you have a ViewController with … Read more