Working on scroll animation

1Weather/UI/View controllers/Onboarding/InitialOnboarding/OnboardingPageControl.swift

@@ -11,6 +11,8 @@ class OnboardingPageControl: UIView {
     //Private
     private let kSpacePerDot: CGFloat = 10
     private let kDotSize: CGSize = .init(width: 9, height: 9)
+    private let kIndicatorSize: CGSize = .init(width: 6, height: 6)
+    private var currentPageIndex = 0
     private let totalPagesCount: Int
     private let indicator = CAShapeLayer()
     private var dots = [CAShapeLayer]()
@@ -18,50 +20,71 @@ class OnboardingPageControl: UIView {
     init(totalPagesCount: Int) {
         self.totalPagesCount = totalPagesCount
         super.init(frame: .zero)
+        self.backgroundColor = .gray
         prepareDots()
         prepareIndicator()
     }
     
     override func layoutSubviews() {
         super.layoutSubviews()
-        self.frame.size.width = CGFloat(totalPagesCount) * kDotSize.width + kSpacePerDot * (CGFloat(totalPagesCount) - 1)
-        self.frame.size.height = kDotSize.height
         
-        //Dots
-        for (index, dot) in dots.enumerated() {
-            let cgIndex = CGFloat(index)
-            let space = index == 0 ? 0 : kSpacePerDot
-            let rect = CGRect(origin: .init(x: cgIndex * (kDotSize.width + space), y: 0), size: kDotSize)
-            dot.path = CGPath(ellipseIn: rect, transform: nil)
-            print("Dot- index: \(index) rect: \(rect)")
-        }
+        //Update Y positions
+        
     }
     
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
     
-    func scroll(toPage index: Int, progress: CGFloat) {
-        var scrollProgress = max(0, progress)
-        scrollProgress = min(progress, 1)
+    func scroll(toPage index: Int, screenTransitionProgress: CGFloat) {
+        guard screenTransitionProgress != 0 else { return }
+        var scrollProgress = max(0, screenTransitionProgress)
+        scrollProgress = min(screenTransitionProgress, 1)
         
+        print("[Page] scroll to \(index) progress: \(scrollProgress)")
+        let targetDot = dots[index]
+        let previousDot = dots[index == 0 ? 0 : index - 1]
+        
+        //Scale
+//        let scaleDelta = (kDotSize.width - kIndicatorSize.width) * scrollProgress
+//        previousDot.frame.size = .init(width: kIndicatorSize.width + scaleDelta, height: kIndicatorSize.height + scaleDelta)
+//        print("[Frame] prev dot frame: \(previousDot.frame)")
+        
+        let delta = targetDot.frame.origin.x - previousDot.frame.origin.x
+        indicator.frame.origin.x = previousDot.frame.origin.x + delta * scrollProgress
     }
 }
 
 private extension OnboardingPageControl {
     func prepareDots() {
-        for _ in 0..<totalPagesCount {
+        for index in 0..<totalPagesCount {
             let dot = CAShapeLayer()
-            dot.fillColor = UIColor.blue.cgColor
+            let cgIndex = CGFloat(index)
+            let space = index == 0 ? 0 : kSpacePerDot
+            let size = index == 0 ? kIndicatorSize : kDotSize
+            
+            let rect: CGRect
+            if index == 0 {
+                rect = .init(origin: .init(x: 0, y: (frame.height - kIndicatorSize.height) / 2), size: size)
+            }
+            else {
+                rect = .init(origin: .init(x: cgIndex * (size.width + space), y: 0), size: size)
+            }
+            
+            dot.frame = rect
+            dot.backgroundColor = UIColor.blue.cgColor
+            dot.cornerRadius = kDotSize.height / 2
             layer.addSublayer(dot)
             dots.append(dot)
         }
     }
     
     func prepareIndicator() {
-        indicator.fillColor = UIColor.red.cgColor
-        indicator.path = UIBezierPath(roundedRect: .init(origin: .zero, size: kDotSize),
-                                      cornerRadius: kDotSize.height / 2).cgPath
+        indicator.backgroundColor = UIColor.red.cgColor
+        indicator.frame = .init(origin: .zero, size: kDotSize)
+        indicator.cornerRadius = kIndicatorSize.height / 2
+        indicator.frame = .init(origin: .init(x: 0, y: (frame.height - kIndicatorSize.height) / 2),
+                                size: kIndicatorSize)
         layer.addSublayer(indicator)
     }
 }

1Weather/UI/View controllers/Onboarding/InitialOnboarding/OnboardingPageController.swift

@@ -46,14 +46,16 @@ enum OnboardingControllerType {
     }
 }
 
-class OnboardingPageController: UIPageViewController {
+class OnboardingPageController: UIPageViewController, UIScrollViewDelegate {
     private let coordinator: AppCoordinator
+    private let control = OnboardingPageControl(totalPagesCount: 3)
     private let pageControl = UIPageControl()
     private let closeButton = UIButton()
     private var pages = [UIViewController]()
     private let skipButton = SelfSizingButton()
     private let nextButton = UIButton()
     private let doneButton = UIButton()
+    private var currentPageIndex = 0
     
     init(coordinator: AppCoordinator) {
         self.coordinator = coordinator
@@ -73,10 +75,13 @@ class OnboardingPageController: UIPageViewController {
         super.viewDidLoad()
         
         #if DEBUG
-            let control = OnboardingPageControl(totalPagesCount: 5)
-        view.addSubview(control)
-        control.frame.origin.x = 100
-        control.frame.origin.y = 80
+            view.addSubview(control)
+        control.snp.makeConstraints { make in
+            make.top.equalToSuperview().inset(80)
+            make.left.equalToSuperview().inset(100)
+            make.width.equalTo(47)
+            make.height.equalTo(9)
+        }
         #else
             fatalError("Remove in release")
         #endif
@@ -88,6 +93,7 @@ class OnboardingPageController: UIPageViewController {
         prepareNextButton()
         prepareDoneButton()
         updateUI()
+        control.sizeToFit()
     }
     
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
@@ -112,12 +118,13 @@ class OnboardingPageController: UIPageViewController {
             let currentViewController = viewControllers?.first,
             let currentIndex = pages.firstIndex(of: currentViewController)
         else {
-            return
+             return
         }
         
         let nextIndex = currentIndex + 1
         guard nextIndex < pages.count else { return }
         setViewControllers([pages[nextIndex]], direction: .forward, animated: true) {[weak self] _ in
+            self?.currentPageIndex = nextIndex
             self?.pageControl.currentPage = nextIndex
             self?.showDoneIfNeeded(for: nextIndex)
         }
@@ -162,6 +169,14 @@ private extension OnboardingPageController {
         dataSource = self
         delegate = self
         setViewControllers([pages[0]], direction: .forward, animated: false)
+        
+        //Try to find scroll view
+        for subview in view.subviews {
+            if subview.isKind(of: UIScrollView.self) {
+                let scrollView = subview as? UIScrollView
+                scrollView?.delegate = self
+            }
+        }
     }
     
     func preparePageControl() {
@@ -249,6 +264,22 @@ private extension OnboardingPageController {
     }
 }
 
+//MARK:- UIScrollView Delegate
+extension OnboardingPageController {
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        let pageWidth = scrollView.contentSize.width / CGFloat(pages.count)
+        let progress = (scrollView.contentOffset.x - pageWidth) / pageWidth
+        print("progress: \(progress)")
+       
+        let nextPageIndex = progress < 0 ? currentPageIndex - 1 : currentPageIndex + 1
+        if nextPageIndex > pages.count - 1 || nextPageIndex < 0 {
+            return
+        }
+        
+        control.scroll(toPage: nextPageIndex, screenTransitionProgress: abs(progress))
+    }
+}
+
 //MARK:- UIPageViewController Data Source
 extension OnboardingPageController: UIPageViewControllerDataSource {
     func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
@@ -281,6 +312,7 @@ extension OnboardingPageController: UIPageViewControllerDelegate {
         }
         
         pageControl.currentPage = currentPageIndex
+        self.currentPageIndex = currentPageIndex
         showDoneIfNeeded(for: currentPageIndex)
     }
 }