UIView extension - Auto Layout Helper

UIView.swift

import UIKit

extension UIView {
    func bottom(to view: UIView, offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        constrain(bottomAnchor, to: usingSafeArea ? view.safeAreaLayoutGuide.bottomAnchor : view.bottomAnchor, of: view, offset: offset)
    }
    
    func topToBottom(of view: UIView, offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        constrain(topAnchor, to: usingSafeArea ? view.safeAreaLayoutGuide.bottomAnchor : view.bottomAnchor, of: view, offset: offset)
    }
    
    func top(to view: UIView, offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        constrain(topAnchor, to: usingSafeArea ? view.safeAreaLayoutGuide.topAnchor : view.topAnchor, of: view, offset: offset)
    }
    
    func right(to view: UIView, offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        constrain(rightAnchor, to: usingSafeArea ? view.safeAreaLayoutGuide.rightAnchor : view.rightAnchor, of: view, offset: offset)
    }
    
    func left(to view: UIView, offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        constrain(leftAnchor, to: usingSafeArea ? view.safeAreaLayoutGuide.leftAnchor : view.leftAnchor, of: view, offset: offset)
    }
    
    func bottomToTop(of view: UIView, offset: CGFloat = 0.0) {
        translatesAutoresizingMaskIntoConstraints = false
        constrain(bottomAnchor, to: view.topAnchor, of: view, offset: offset)
    }
    
    func rightToLeft(of view: UIView?, offset: CGFloat = 0.0) {
        constrain(rightAnchor, to: view?.leftAnchor, of: view, offset: offset)
    }
    
    func leftToRight(of view: UIView?, offset: CGFloat = 0.0) {
        constrain(leftAnchor, to: view?.rightAnchor, of: view, offset: offset)
    }
    
    func centerX(to view: UIView, offset: CGFloat = 0.0) {
        constrain(centerXAnchor, to: view.centerXAnchor, of: view, offset: offset)
    }
    
    func centerY(to view: UIView, offset: CGFloat = 0.0) {
        constrain(centerYAnchor, to: view.centerYAnchor, of: view, offset: offset)
    }
    
    func center(to view: UIView) {
        guard superview == view.superview else { fatalError("Views do not belong in the same hierarchy") }
        centerY(to: view)
        centerX(to: view)
    }
}

// MARK: - Superview Functions
extension UIView {
    enum Edge: CaseIterable { case top, bottom, left, right, none }
    
    func edgesToSuperview(excluding: Edge = .none, insets: UIEdgeInsets = .zero, usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        Edge.allCases.filter { $0 != excluding }.forEach {
            switch $0 {
            case .top: top(to: superview, offset: insets.top, usingSafeArea: usingSafeArea)
            case .right: right(to: superview, offset: -insets.right, usingSafeArea: usingSafeArea)
            case .bottom: bottom(to: superview, offset: -insets.bottom, usingSafeArea: usingSafeArea)
            case .left: left(to: superview, offset: insets.left, usingSafeArea: usingSafeArea)
            case .none: return
            }
        }
    }
    
    func bottomToSuperview(offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        bottom(to: superview, offset: offset, usingSafeArea: usingSafeArea)
    }
    
    func topToSuperview(offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        top(to: superview, offset: offset, usingSafeArea: usingSafeArea)
    }
    
    func rightToSuperview(offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        right(to: superview, offset: offset, usingSafeArea: usingSafeArea)
    }
    
    func leftToSuperview(offset: CGFloat = 0.0, usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        left(to: superview, offset: offset, usingSafeArea: usingSafeArea)
    }
    
    func centerXToSuperview(usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        centerX(to: superview)
    }
    
    func centerYToSuperview(usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        centerY(to: superview)
    }
    
    func centerToSuperview() {
        guard let superview = superview else { fatalError("View does not have a superview") }
        center(to: superview)
    }
    
    func widthToSuperview(usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        width(to: superview, usingSafeArea: usingSafeArea)
    }
    
    func heightToSuperview(usingSafeArea: Bool = false) {
        guard let superview = superview else { fatalError("View does not have a superview") }
        height(to: superview, usingSafeArea: usingSafeArea)
    }
}

// MARK:- Base Functions
extension UIView {
    func width(to view: UIView, usingSafeArea: Bool = false) {
        translatesAutoresizingMaskIntoConstraints = false
        constrain(widthAnchor, to: view.widthAnchor, of: view)
    }
    
    func height(to view: UIView, usingSafeArea: Bool = false) {
        translatesAutoresizingMaskIntoConstraints = false
        constrain(heightAnchor, to: view.heightAnchor, of: view)
    }
    
    func height(_ height: CGFloat) {
        translatesAutoresizingMaskIntoConstraints = false
        heightAnchor.constraint(equalToConstant: height).isActive = true
    }
    
    func width(_ width: CGFloat) {
        translatesAutoresizingMaskIntoConstraints = false
        widthAnchor.constraint(equalToConstant: width).isActive = true
    }
    
    func aspectRation(_ ratio: CGFloat) {
        widthAnchor.constraint(equalTo: heightAnchor, multiplier: ratio).isActive = true
    }
    
    fileprivate func constrain(_ from: NSLayoutDimension, to: NSLayoutDimension, of view: UIView) {
//        guard superview == view.superview else { fatalError("Views do not belong in the same hierarchy") }
        translatesAutoresizingMaskIntoConstraints = false
        from.constraint(equalTo: to).isActive = true
    }
    
    fileprivate func constrain(_ from: NSLayoutYAxisAnchor, to: NSLayoutYAxisAnchor?, of view: UIView?, offset: CGFloat = 0.0) {
//        guard superview == view.superview else { fatalError("Views do not belong in the same hierarchy") }
        translatesAutoresizingMaskIntoConstraints = false
        guard let to = to else { return }
        from.constraint(equalTo: to, constant: offset).isActive = true
    }
    
    fileprivate func constrain(_ from: NSLayoutXAxisAnchor, to: NSLayoutXAxisAnchor?, of view: UIView?, offset: CGFloat = 0.0) {
//        guard superview == view.superview else { fatalError("Views do not belong in the same hierarchy") }
        translatesAutoresizingMaskIntoConstraints = false
        guard let to = to else { return }
        from.constraint(equalTo: to, constant: offset).isActive = true
    }
}