Hook

Quick Guide

let yellowView = UIView()
yellowView.backgroundColor = .yellow

let stackView = UIStackView()
stackView.axis = .vertical

let greenView = UIView()
greenView.backgroundColor = .green

let redView = UIView()
redView.backgroundColor = .red

let bottomTrailingView = UIView()
bottomTrailingView.backgroundColor = .blue

// Hook helper
view.addSubviews(yellowView, stackView, bottomTrailingView)
stackView.addArrangedSubviews(greenView, redView)

// Hook all side
yellowView.hook.all(to: view)

// Hook top, leading, trailing
stackView.hook
    .top(equalTo: yellowView.safeAreaLayoutGuide.topAnchor, constant: 20)
    .leading(equalTo: yellowView.leadingAnchor)
    .trailing(equalTo: yellowView.trailingAnchor)

// Hook trailing, bottom, width, height
bottomTrailingView.hook
    .trailing(equalTo: view.trailingAnchor)
    .bottom(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
    .width(equalTo: view.widthAnchor, multiplier: 0.5)
    .height(greaterThanOrEqualTo: redView.heightAnchor)

// Hook height
greenView.hook.height(equalToConstant: 200)

// Hook height
redView.hook.height(equalTo: greenView.heightAnchor)

Comparison

NSLayoutConstraint

addSubview(aView)
aView.translatesAutoresizingMaskIntoConstraints = false

addSubview(bView)
bView.translatesAutoresizingMaskIntoConstraints = false

NSLayoutConstraint.activate([
    aView.topAnchor.constraint(equalTo: topAnchor),
    aView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20),
    aView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -20),
    aView.heightAnchor.constraint(greaterThanOrEqualToConstant: 40),

    bView.topAnchor.constraint(equalTo: aView.bottomAnchor, constant: 10),
    bView.centerXAnchor.constraint(equalTo: aView.centerXAnchor),
    bView.widthAnchor.constraint(equalTo: aView.widthAnchor, multiplier: 1.2),
    bView.heightAnchor.constraint(lessThanOrEqualTo: aView.heightAnchor)
])

Hook

addSubviews(aView, bView)

aView.hook
    .top(equalTo: topAnchor)
    .leading(equalTo: leadingAnchor, constant: 20)
    .trailing(equalTo: trailingAnchor, constant: -20)
    .height(greaterThanOrEqualConstant: 40)

bView.hook
    .top(equalTo: aView.bottomAnchor, constant: 10)
    .centerX(equalTo: aView.centerXAnchor)
    .width(equalTo: aView.widthAnchor, multiplier: 1.2)
    .height(lessThanOrEqualTo: aView.heightAnchor)

You can reduce typing via all(to:topConstant:leadingConstant:bottomConstant:trailingConstant:safeAreaSides).

bView.hook.all(to: self)

And you can easily set priority via priority parameter.

bView.hook.height(to: aView.height, priority: .defaultLow)

Also, you can easily access NSLayoutConstraint via constraint(_:).

bView.hook.constraint(.height)?.isActive = false
bView.hook.height(equalToConstant: 300)
// OR
bView.hook.constraint(.height)?.constant = 20

Example

To run the example project, clone the repo, and run pod install from the Example directory first.

Requirements

iOS 11.0+

Installation

Cocoapods

Hook is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'Hook'

SPM

Hook is available also SPM. To install it, simply add the following line to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/lyfeoncloudnine/Hook.git", .upToNextMajor(from: "1.0.0"))
]

Author

lyfeoncloudnine, lyfeoncloudnine@gmail.com

License

Hook is available under the MIT license. See the LICENSE file for more info.