zenangst

let options: UIViewAnimationOptions = [.allowUserInteraction, .beginFromCurrentState]
UIView.animate(withDuration: 0.4, delay: 0.0, options: options, animations: {
  self.headerViewController.view.frame.size.height = 120
  self.contentViewController.view.frame.size.height = 320
  self.moreViewController.view.frame.size.height = 210
})

zenangst

import UIKit

extension CALayer {
  /// Resolve animation duration of the first animation using animation keys.
  var resolveAnimationDuration: CFTimeInterval? {
    if let firstKey = animationKeys()?.first,
      let animation = animation(forKey: firstKey) {
      return animation.duration
    }

zenangst

let animationDuration: TimeInterval? = subviewsInLayoutOrder
  .flatMap({ $0.layer.resolveAnimationDuration }).first ?? duration

if let duration = animationDuration {
  let options: UIViewAnimationOptions = [.allowUserInteraction, .beginFromCurrentState]
  UIView.animate(withDuration: duration, delay: 0.0, options: options, animations: {
    self.runLayoutSubviewsAlgorithm()
  })
} else {
  runLayoutSubviewsAlgorithm()

zenangst

let familyController = FamilyViewController()
let viewController = UIViewController()

familyController.addChildViewController(viewController)

zenangst

let familyController = FamilyViewController()
let viewController = UIViewController()

familyController.addChildViewController(viewController, height: 175)

zenangst

let familyController = FamilyViewController()
let customController = CustomViewController()

familyController.addChildViewController(customController, view: { $0.scrollView })

zenangst

import UIKit

let frame = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
let view = UIView(frame: frame)

view.backgroundColor = UIColor.blue

zenangst

import Cocoa

let frame = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
let view = NSView(frame: frame)

view.wantsLayer = true
view.layer?.backgroundColor = NSColor.blue.cgColor

zenangst

import UIKit

class MyViewController: UIViewController {}

let frame = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
let viewController = MyViewController()
viewController.view.frame = frame

zenangst

import Cocoa

class MyViewController: NSViewController {}

let frame = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
let viewController = MyViewController()
viewController.view.frame = frame