Tab Bar: Add a bottom separator

App/Tabs/TabBarView.swift

@@ -121,6 +121,8 @@ class TabBarView: UIView
     private var activeTabIndex: Int = 0
     private var tabContainerView = UIScrollView(frame: .zero)
     
+    private let bottomSeparatorView = UIView(frame: .zero)
+    
     override func sizeThatFits(_ size: CGSize) -> CGSize {
         CGSize(width: size.width, height: Self.preferredHeight)
     }
@@ -132,6 +134,9 @@ class TabBarView: UIView
         backgroundColor = .secondarySystemGroupedBackground
         tabContainerView.showsHorizontalScrollIndicator = false
         tabContainerView.showsVerticalScrollIndicator = false
+        
+        addSubview(bottomSeparatorView)
+        bottomSeparatorView.backgroundColor = .systemFill
     }
     
     public func reloadTabs() {
@@ -196,6 +201,12 @@ class TabBarView: UIView
         let tabContainerBounds = bounds
         tabContainerView.frame = tabContainerBounds
         
+        let separatorHeight = CGFloat(1.0)
+        bottomSeparatorView.frame = CGRect(
+            x: 0.0, y: bounds.height - separatorHeight,
+            width: bounds.width, height: separatorHeight
+        )
+        
         let minimumTabWidth = { (traitCollection: UITraitCollection) -> CGFloat in
             if traitCollection.horizontalSizeClass == .compact {
                 return tabContainerBounds.width / 3.0