Add option to select a different vertical alignment for ButtonBar’s SelectedBar: top, middle or bottom (default).

Sources/ButtonBarPagerTabStripViewController.swift

@@ -49,6 +49,7 @@ public struct ButtonBarPagerTabStripSettings {
 
         public var selectedBarBackgroundColor = UIColor.black
         public var selectedBarHeight: CGFloat = 5
+        public var selectedBarVerticalAlignment: SelectedBarVerticalAlignment = .bottom
         
         public var buttonBarItemBackgroundColor: UIColor?
         public var buttonBarItemFont = UIFont.systemFont(ofSize: 18)
@@ -147,6 +148,8 @@ open class ButtonBarPagerTabStripViewController: PagerTabStripViewController, Pa
         buttonBarView.selectedBar.backgroundColor = settings.style.selectedBarBackgroundColor
         
         buttonBarView.selectedBarHeight = settings.style.selectedBarHeight
+        buttonBarView.selectedBarVerticalAlignment = settings.style.selectedBarVerticalAlignment
+        
         // register button bar item cell
         switch buttonBarItemSpec! {
         case .nibFile(let nibName, let bundle, _):

Sources/ButtonBarView.swift

@@ -37,6 +37,12 @@ public enum SelectedBarAlignment {
     case progressive
 }
 
+public enum SelectedBarVerticalAlignment {
+    case top
+    case middle
+    case bottom
+}
+
 open class ButtonBarView: UICollectionView {
     
     open lazy var selectedBar: UIView = { [unowned self] in
@@ -50,6 +56,7 @@ open class ButtonBarView: UICollectionView {
             updateSelectedBarYPosition()
         }
     }
+    var selectedBarVerticalAlignment: SelectedBarVerticalAlignment = .bottom
     var selectedBarAlignment: SelectedBarAlignment = .center
     var selectedIndex = 0
     
@@ -167,7 +174,16 @@ open class ButtonBarView: UICollectionView {
     
     private func updateSelectedBarYPosition() {
         var selectedBarFrame = selectedBar.frame
-        selectedBarFrame.origin.y = frame.size.height - selectedBarHeight
+        
+        switch selectedBarVerticalAlignment {
+        case .top:
+            selectedBarFrame.origin.y = 0
+        case .middle:
+            selectedBarFrame.origin.y = (frame.size.height - selectedBarHeight) / 2
+        case .bottom:
+            selectedBarFrame.origin.y = frame.size.height - selectedBarHeight
+        }
+        
         selectedBarFrame.size.height = selectedBarHeight
         selectedBar.frame = selectedBarFrame
     }