Digital ACT-191 ONEAPP-7013 story: Updating scrollbar position on scrolling carousel content

VDS/Components/Carousel/Carousel.swift

@@ -365,7 +365,6 @@ open class Carousel: View {
         }
 
         updatePaginationControls()
-        getSlotWidth()
         addCarouselSlots()
     }
     
@@ -386,6 +385,7 @@ open class Carousel: View {
     // MARK: - Private Methods
     //--------------------------------------------------
     private func addCarouselSlots() {
+        getSlotWidth()
         if containerView.frame.size.width > 0 {
             containerViewHeightConstraint?.isActive = false
             containerStackHeightConstraint?.isActive = false
@@ -405,6 +405,7 @@ open class Carousel: View {
                         $0.backgroundColor = UIColor(red: CGFloat(216) / 255.0, green: CGFloat(218) / 255.0, blue: CGFloat(218) / 255.0, alpha: 1)
                     }
                     scrollView.addSubview(carouselSlot)
+                    scrollView.delegate = self
                     let size = ratioSize(for: minimumSlotWidth)
                     slotHeight = size.height
                     carouselSlot
@@ -553,15 +554,49 @@ open class Carousel: View {
         if carouselScrollBar.numberOfSlides > 0 {
             let scrollContentSizeWidth = scrollView.contentSize.width
             let totalPositions = totalPositions()
-            let multiplier: Float = (position == 1) ? 0 : Float((position)-1) / Float(totalPositions)
+            var xPos = 0.0
-            let xPos = (position == totalPositions) ? (scrollContentSizeWidth - containerView.frame.size.width) : CGFloat(Float(scrollContentSizeWidth) * multiplier)
+            if position == 1 {
-            carouselScrollBar.scrubberId = position
+                xPos = 0.0
+            } else if position == totalPositions {
+                xPos = scrollContentSizeWidth - containerView.frame.size.width
+            } else {
+                let isScrollbarSuppressed = data.count > 0 && layout.value == data.count
+                let isPeekMinimumOnTablet = UIDevice.isIPad && peek == .minimum
+                if !isScrollbarSuppressed {
+                    let subpart = minimumSlotWidth + gutter.value
+                    let xPosition = CGFloat( Float(position-1) * Float(layout.value) * Float(subpart))
+                    switch peek {
+                    case .standard:
+                        if UIDevice.isIPad {
+                            xPos =  xPosition - (minimumSlotWidth/(CGFloat(layout.value) + 3))/2
+                        } else if layout == .oneUP {
+                            xPos = xPosition - gutter.value - (minimumSlotWidth/4)/2
+                        }
+                    case .minimum:
+                        xPos = isPeekMinimumOnTablet ? xPosition : xPosition - peekMinimum/2
+                    case .none:
+                        xPos = xPosition
+                    }
+                }
+            }
+            carouselScrollBar.scrubberId = position+1
             let yPos = scrollView.contentOffset.y
             scrollView.setContentOffset(CGPoint(x: xPos, y: yPos), animated: true)
             showPaginationControls()
         }
     }
     
+    func updateScrollbarPosition(targetContentOffsetXPos:CGFloat) {
+        let scrollContentSizeWidth = scrollView.contentSize.width
+        let totalPositions = totalPositions()
+        let layoutSpace = Int (floor( Double(scrollContentSizeWidth / Double(totalPositions))))
+        let remindSpace = Int(targetContentOffsetXPos) % layoutSpace
+        var contentPos = (Int(targetContentOffsetXPos) / layoutSpace) + 1
+        contentPos = remindSpace > layoutSpace/2 ? contentPos+1 : contentPos
+        carouselScrollBar.position = contentPos
+        updateScrollPosition(position: contentPos, callbackText: "ScrollViewMoved")
+    }
+
     private func totalPositions() -> Int {
         return Int (ceil (Double(carouselScrollBar.numberOfSlides) / Double(_layout.value)))
     }
@@ -576,3 +611,17 @@ open class Carousel: View {
         }
     }
 }
+
+extension Carousel: UIScrollViewDelegate {
+    //--------------------------------------------------
+    // MARK: - UIScrollView Delegate
+    //--------------------------------------------------
+    public func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
+        updateScrollbarPosition(targetContentOffsetXPos: targetContentOffset.pointee.x)
+    }
+    public func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+        var visibleRect = CGRect()
+        visibleRect.origin = scrollView.contentOffset
+        updateScrollbarPosition(targetContentOffsetXPos: visibleRect.origin.x)
+    }
+}