Set Visibility of SignIn / SignUp button when User is in the last page of UIPageControl

Question

I have a viewcontroller (OnboardingMasterViewController.swift) with a UIScrollView, Page Control, and 2 button for SignIn / SignUp and Not Now in the lower part. Here the overview :

Onboarding Storyboard

I wonder, how to make this 2 button only appear if the user reaches the last page. How do I pass the bool value that will make the buttons appear?

I already try by create a func called lastPageReached() and called it in viewDidLoad(). It can hide the button but cannot be unhide when it reach the last array.

This is the full code i use for my OnboardingMasterViewController.

//
class OnboardingMasterViewController: UIViewController, UIScrollViewDelegate {

@IBOutlet weak var scrollView: UIScrollView!
@IBOutlet weak var pageControl: UIPageControl!
@IBOutlet weak var btnSignUp: UIButton!
@IBOutlet weak var btnNotNow: UIButton!

var scrollWidth: CGFloat! = 0.0
var scrollHeight: CGFloat! = 0.0

// data for slides
var titles = ["Welcome to Sistakedi!", "Easy to input", "Easy to access", "Easy to see the trend"]
var descs = ["This application will help you to record and manage your health condition.","Sistakedi have a simple way to record your blood pressure, blood glucose and cholesterol.","Not just easy to record, you can easilly find your health data in our journal.", "And you can also understand your health condition by see your health history in graphic."]
var imgs = ["intro1","intro2","intro3","intro4"]

// get dynamic width and height of scrollview and save it
override func viewDidLayoutSubviews() {
    scrollWidth = scrollView.frame.size.width
    scrollHeight = scrollView.frame.size.height
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.view.layoutIfNeeded()
    //to call viewDidLayoutSubviews() and get dynamic width and height of scrollview

    self.scrollView.delegate = self
    scrollView.isPagingEnabled = true
    scrollView.showsHorizontalScrollIndicator = false
    scrollView.showsVerticalScrollIndicator = false

    //crete the slides and add them
    var frame = CGRect(x: 0, y: 0, width: 0, height: 0)

    for index in 0..<titles.count {
        frame.origin.x = scrollWidth * CGFloat(index)
        frame.size = CGSize(width: scrollWidth, height: scrollHeight)

        let slide = UIView(frame: frame)

        //subviews
        let imageView = UIImageView.init(image: UIImage.init(named: imgs[index]))
        imageView.frame = CGRect(x:0,y:0,width:300,height:300)
        imageView.contentMode = .scaleAspectFit
        imageView.center = CGPoint(x:scrollWidth/2,y: scrollHeight/2 - 50)

        let txt1 = UILabel.init(frame: CGRect(x:32,y:imageView.frame.maxY+10,width:scrollWidth-64,height:80))
        txt1.textAlignment = .center
        txt1.font = UIFont.boldSystemFont(ofSize: 20.0)
        txt1.text = titles[index]

        let txt2 = UILabel.init(frame: CGRect(x:32,y:txt1.frame.maxY+10,width:scrollWidth-64,height:80))
        txt2.textAlignment = .center
        txt2.numberOfLines = 4
        txt2.font = UIFont.systemFont(ofSize: 18.0)
        txt2.text = descs[index]

        slide.addSubview(imageView)
        slide.addSubview(txt1)
        slide.addSubview(txt2)
        scrollView.addSubview(slide)

        lastPageReached()

    }

    scrollView.contentSize = CGSize(width: scrollWidth * CGFloat(titles.count), height: scrollHeight)

    //disable vertical scroll/bounce
    self.scrollView.contentSize.height = 1.0

    //initial state
    pageControl.numberOfPages = titles.count
    pageControl.currentPage = 0

}


//indicator
@IBAction func pageChanged(_ sender: Any) {
    scrollView!.scrollRectToVisible(CGRect(x: scrollWidth * CGFloat ((pageControl?.currentPage)!), y: 0, width: scrollWidth, height: scrollHeight), animated: true)
}

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
    setIndiactorForCurrentPage()
}

func setIndiactorForCurrentPage()  {
    let page = (scrollView?.contentOffset.x)!/scrollWidth
    pageControl?.currentPage = Int(page)
}

func lastPageReached() {
    if titles.count == 3 {
        btnNotNow.isHidden = false
        btnNotNow.isHidden = false
    } else {
        btnNotNow.isHidden = true
        btnSignUp.isHidden = true
    }
}

Answer 1

The simplest way I can think to do this is to have the logic inside your setIndicatorForCurrentPage method.

func setIndiactorForCurrentPage()  {
    let page = Int((scrollView?.contentOffset.x)!/scrollWidth)
    pageControl?.currentPage = page
    if page == titles.count - 1 {
        //This is the last page
        btnSignUp.isHidden = false
        btnNotNow.isHidden = false
    } else {
        //If you want to hide the button again in case the user goes backward through your pages
        btnSignUp.isHidden = true
        btnNotNow.isHidden = true
    }
}