Finished scroll indicator

1Weather/Cells/CurrentForecastDetailsCell.swift

@@ -6,6 +6,7 @@
 //
 
 import UIKit
+import SnapKit
 
 private class InfoCardView:UIView {
     private let valueLabel = UILabel()
@@ -58,6 +59,9 @@ class CurrentForecastDetailsCell: UITableViewCell {
     private let stackView = UIStackView()
     private let progressView = UIView()
     private let progressIndicator = UIView()
+    private let kIndicatorWidth:CGFloat = 16
+    private var indicatorWidthConstraint:Constraint?
+    private var indicatorLeftConstraint:Constraint?
     
     override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
         super.init(style: style, reuseIdentifier: reuseIdentifier)
@@ -98,6 +102,7 @@ private extension CurrentForecastDetailsCell {
         scrollView.contentInset = .init(top: 0, left: 16, bottom: 0, right: 16)
         scrollView.showsVerticalScrollIndicator = false
         scrollView.showsHorizontalScrollIndicator = false
+        scrollView.delegate = self
         contentView.addSubview(scrollView)
         
         scrollView.snp.makeConstraints { (make) in
@@ -182,11 +187,23 @@ private extension CurrentForecastDetailsCell {
         progressIndicator.layer.cornerRadius = 2
         progressIndicator.clipsToBounds = true
         progressView.addSubview(progressIndicator)
-        progressIndicator.snp.makeConstraints { (make) in
+        progressIndicator.snp.makeConstraints {[weak self] (make) in
             make.height.equalToSuperview()
-            make.left.equalToSuperview()
+            self?.indicatorLeftConstraint = make.left.equalToSuperview().constraint
             make.centerY.equalToSuperview()
-            make.width.equalTo(16)
+            self?.indicatorWidthConstraint = make.width.equalTo(kIndicatorWidth).constraint
         }
     }
 }
+
+//MARK:- UIScrollView Delegate
+extension CurrentForecastDetailsCell: UIScrollViewDelegate {
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        let totalContentWidth = scrollView.contentSize.width + scrollView.contentInset.left + scrollView.contentInset.right
+        let scrollProgress = (scrollView.contentOffset.x + scrollView.contentInset.left)
+                                / (totalContentWidth - scrollView.bounds.width)
+        
+        let multiplier = (progressView.bounds.width - kIndicatorWidth) / kIndicatorWidth
+        indicatorLeftConstraint?.layoutConstraints.first?.constant = multiplier * scrollProgress * kIndicatorWidth
+    }
+}