ScrollViewSupportViewController.swift

//
//  ScrollViewSupportViewController.swift
//  Sample
//
//  Created by Jayesh Kawli on 2/23/19.
//  Copyright © 2019 Jayesh Kawli. All rights reserved.
//

import UIKit

class ScrollViewSupportViewController: UIViewController {

    enum Constants {
        static let horizontalPadding: CGFloat = 20.0
        static let verticalPadding: CGFloat = 100.0
    }

    var autolayoutScrollView: ScrollViewAutolayoutCreator!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = .white

        self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Top", style: .done, target: self, action: #selector(goToTop))
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Bottom", style: .done, target: self, action: #selector(goToBottom))

        autolayoutScrollView = ScrollViewAutolayoutCreator(superView: view)

        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.numberOfLines = 0

        label.text = "hello hi buddy\nadadasd\nadadasdas d sd asd asd \na da d adas d\nasdasd"
        label.backgroundColor = .green

        let sampleView = UIView()
        sampleView.translatesAutoresizingMaskIntoConstraints = false
        sampleView.backgroundColor = .red

        let bottomLabel = UILabel()
        bottomLabel.translatesAutoresizingMaskIntoConstraints = false
        bottomLabel.numberOfLines = 0

        bottomLabel.text = "hello hi buddy\nadadasd\nadadasdas d sd asd asd \na da d adas d\nasdasd"
        bottomLabel.backgroundColor = .yellow

        let contentView = autolayoutScrollView.contentView

        contentView.addSubview(label)
        contentView.addSubview(sampleView)
        contentView.addSubview(bottomLabel)

        // Attach horizontal Constraints
        autolayoutScrollView.addHorizontalConstraints(views: [label, sampleView, bottomLabel], horizontalPadding: Constants.horizontalPadding)

        // MARK: Optional Vertical Constraints for positions. This can be done manually or through library as depicted in example below.
//        NSLayoutConstraint.activate([
//            label.topAnchor.constraint(equalTo: contentView.topAnchor, constant: Constants.padding),
//            sampleView.topAnchor.constraint(equalTo: label.bottomAnchor, constant: 400.0),
//            bottomLabel.topAnchor.constraint(equalTo: sampleView.bottomAnchor, constant: 400.0),
//            bottomLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -Constants.padding)
//            ])

        autolayoutScrollView.addVerticalConstraints(views: [label, sampleView, bottomLabel], verticalPadding: Constants.verticalPadding)

        // Vertical Constraints for height. Make sure these are set up correctly in the client code. Library doesn't have support to add height constraints for individual views
        NSLayoutConstraint.activate([
            sampleView.heightAnchor.constraint(equalToConstant: 200.0)
            ])
    }
}

extension ScrollViewSupportViewController {
    @objc func goToTop() {
        autolayoutScrollView.scrollToTop()
    }

    @objc func goToBottom() {
        autolayoutScrollView.scrollToBottom()
    }
}