/Layoutable

Extension for UIView that make use of Auto Layout easier.

Primary LanguageSwiftMIT LicenseMIT

Layoutable is an extension for UIView apps that make use of Auto Layout easier. This framework doesn't replace any existing Auto Layout API available in UIKit. Anchor API is very good and easy to use, but sometimes require a lot of code repetition for common tasks. This framework only adds a couple of useful extensions. You can check the implementation in just one single file.

Usage & features

Here's how the code would look like when constraining the screen above. See the example for the full version.

Just UIKit

import UIKit

final class ViewController: UIViewController {

    private let headerView: UIView = {
        let view = UIView()
        view.backgroundColor = .white
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

    [...]

    override func loadView() {
        [...]

        NSLayoutConstraint.activate([
            headerView.topAnchor.constraint(equalTo: view.topAnchor),
            headerView.leftAnchor.constraint(equalTo: view.leftAnchor),
            headerView.rightAnchor.constraint(equalTo: view.rightAnchor),
            headerView.heightAnchor.constraint(equalToConstant: 200),

            headerCenterView.widthAnchor.constraint(equalToConstant: 80),
            headerCenterView.heightAnchor.constraint(equalToConstant: 80),
            headerCenterView.centerXAnchor.constraint(equalTo: headerView.centerXAnchor),
            headerCenterView.centerYAnchor.constraint(equalTo: headerView.centerYAnchor),

            contentContainerView.topAnchor.constraint(equalTo: headerView.bottomAnchor),
            contentContainerView.leftAnchor.constraint(equalTo: view.leftAnchor),
            contentContainerView.rightAnchor.constraint(equalTo: view.rightAnchor),
            contentContainerView.bottomAnchor.constraint(equalTo: view.bottomAnchor),

            contentView.topAnchor.constraint(equalTo: contentContainerView.topAnchor, constant: 80),
            contentView.leftAnchor.constraint(equalTo: contentContainerView.leftAnchor, constant: 20),
            contentView.rightAnchor.constraint(equalTo: contentContainerView.rightAnchor, constant: -20),
            contentView.bottomAnchor.constraint(equalTo: contentContainerView.bottomAnchor, constant: -20),
        ])
    }
}

UIKit + Layoutable

import UIKit
import Layoutable

final class ViewController: UIViewController {

    private let headerView: UIView = {
        let view = UIView()
        view.backgroundColor = .white
        return view.layoutable()
    }()

    [...]

    override func loadView() {
        [...]

        headerView.constrainToSuperviewEdges(excluding: [.bottom])
        headerView.heightAnchor.constraint(equalToConstant: 200).isActive = true

        headerCenterView.constrainToConstant(size: .init(width: 80, height: 80))
        headerCenterView.constrainCenterToSuperview()

        contentContainerView.constrainToSuperviewEdges(excluding: [.top])
        contentContainerView.topAnchor.constraint(equalTo: headerView.bottomAnchor).isActive = true

        contentView.constrainToSuperviewEdges(insets: .init(top: 80, left: 20, bottom: 20, right: 20))
    }
}

Detecting if view can be used with Auto Layout

For all of the views that you want to use with Auto Layout you have to type translatesAutoresizingMaskIntoConstraints = false. It's very easy to forget and have a lot of conflicts after running your app. Layoutable checks for this situation and informs you how to fix it.

Requirements

Layoutable supports iOS 9.0 or higher.

Installation

Carthage

If you're using Carthage, add the following dependency to your Cartfile:

github "MichalTKwiecien/Layoutable" {version}

CocoaPods

If you're using CocoaPods, add the following dependency to your Podfile:

pod 'Layoutable', '~> {version}'

Manually

You can just drag and drop single file to your project.

Contributing

Development requires following tools:

After cloning the repository, install project's dependencies:

$ carthage bootstrap --platform iOS