LabelIntrinsicContentSize.swift

/*:
 
 Paste this into Swift Playgrounds on an iPad to see how
 modifying a label's frame affects its intrinsicContentSize.
 
 As near as I can tell, frame currently does not affect
intrinsicContentSize.

At least I am sure it did not used to affect it.
 
 */



import UIKit
import PlaygroundSupport

class ViewController : UIViewController
{
    let v = UIView(frame: .zero)
    let label = UILabel(frame: .zero)
    let button1 = UIButton(type: UIButtonType.custom)
    let but2 = UIButton(type: .custom)
    
    override func loadView() {
        v.translatesAutoresizingMaskIntoConstraints = false
        v.backgroundColor = .green
        self.view = v
        setupLabel()
        setupButton()

    }
    
    func setupLabel() {
        label.text = repeatElement("Hello world. ", count: 1).joined(separator: "")
        label.backgroundColor = .white
        
        v.addSubview(label)
        label.translatesAutoresizingMaskIntoConstraints = false
        
        label.centerXAnchor.constraint(equalTo: label.superview!.centerXAnchor).isActive = true
        label.centerYAnchor.constraint(equalTo: label.superview!.centerYAnchor).isActive = true
    }
    
    func setupButton() {
        button1.setTitle("log (lastLog= none)", for: .normal)
        button1.addTarget(self, action: #selector(logICS), for: .touchUpInside)
        but2.setTitle("set frame", for: .normal)
        but2.addTarget(self, action: #selector(expandFrame), for: .touchUpInside)
        
        let sv = UIStackView(arrangedSubviews: [but2,button1])
        sv.axis = UILayoutConstraintAxis.horizontal
        sv.distribution = UIStackViewDistribution.fillProportionally
        
        v.addSubview(sv)
        sv.translatesAutoresizingMaskIntoConstraints=false
        sv.centerXAnchor.constraint(equalTo: sv.superview!.centerXAnchor).isActive = true
        sv.widthAnchor.constraint(equalTo: sv.superview!.widthAnchor).isActive =  true
        sv.bottomAnchor.constraint(equalTo: sv.superview!.bottomAnchor).isActive = true
    }
    
    @objc
    func logICS() {
        let s = "log (lastLog= ics: \(label.intrinsicContentSize);\n\tframe: \(label.frame))"
        self.button1.titleLabel?.numberOfLines = 2
        self.button1.setTitle(s, for: .normal)
        print(label.intrinsicContentSize)
        print(label.frame)
    }
    
    @objc
    func expandFrame() {
        self.label.frame = self.label.frame.insetBy(dx: -50, dy: 0)
    }
    
    @objc
    func shrinkFrameToFitSuperview() {
        label.frame = label.frame.intersection(label.superview!.bounds)
    }
    
}

PlaygroundPage.current.liveView = ViewController()
PlaygroundPage.current.needsIndefiniteExecution = true