Calculate Bottom Commanding header height instead of using constant (#2041)

* calculate header height instead of using constant

* remove headerHeight var

* update comment

ios/FluentUI.Demo/FluentUI.Demo/Demos/BottomCommandingDemoController.swift

@@ -46,7 +46,8 @@ class BottomCommandingDemoController: DemoController {
 
     private lazy var heroItems: [CommandingItem] = {
         return Array(1...25).map {
-            let item = CommandingItem(title: "Item " + String($0), image: homeImage, action: commandAction)
+            let title = ($0 == 4) ? "Two line item" : "Item"
+            let item = CommandingItem(title: title + String($0), image: homeImage, action: commandAction)
             item.selectedImage = homeSelectedImage
             item.isOn = ($0 % 3 == 1)
             item.isEnabled = ($0 % 2 == 1)

ios/FluentUI/Bottom Commanding/BottomCommandingController.swift

@@ -402,7 +402,6 @@ open class BottomCommandingController: UIViewController, TokenizedControlInterna
         headerView.addSubview(heroCommandStack)
 
         let sheetController = BottomSheetController(headerContentView: headerView, expandedContentView: makeSheetExpandedContent(with: tableView))
-        sheetController.headerContentHeight = Constants.BottomSheet.headerHeight
         sheetController.hostedScrollView = tableView
         sheetController.isHidden = isHidden
         sheetController.shouldAlwaysFillWidth = sheetShouldAlwaysFillWidth
@@ -534,6 +533,7 @@ open class BottomCommandingController: UIViewController, TokenizedControlInterna
         } else {
             tableView.tableHeaderView = nil
         }
+        calculateHeaderHeight()
     }
 
     private func reloadHeroCommandOverflowStack() {
@@ -563,6 +563,13 @@ open class BottomCommandingController: UIViewController, TokenizedControlInterna
         }
     }
 
+    @discardableResult
+    private func calculateHeaderHeight() -> CGFloat {
+        let headerHeight = heroCommandStack.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height + BottomSheetController.resizingHandleHeight
+        bottomSheetController?.headerContentHeight = headerHeight
+        return headerHeight
+    }
+
     private func updateAppearance() {
         guard isViewLoaded else {
             return
@@ -923,7 +930,7 @@ open class BottomCommandingController: UIViewController, TokenizedControlInterna
         let headerHeightWithoutBottomWhitespace = BottomCommandingTokenSet.handleHeaderHeight + maxHeroItemHeight
 
         // How much more whitespace is required at the bottom of the sheet header
-        let requiredBottomWhitespace = max(0, Constants.BottomSheet.headerHeight - headerHeightWithoutBottomWhitespace)
+        let requiredBottomWhitespace = max(0, calculateHeaderHeight() - headerHeightWithoutBottomWhitespace)
 
         // The safe area inset can fulfill some or all of our bottom whitespace requirement.
         // This is how much more we need, taking the inset into account.
@@ -1118,10 +1125,6 @@ open class BottomCommandingController: UIViewController, TokenizedControlInterna
             static let moreButtonIcon: UIImage? = UIImage.staticImageNamed("more-24x24")
             static let moreButtonTitle: String = "CommandingBottomBar.More".localized
         }
-
-        struct BottomSheet {
-            static let headerHeight: CGFloat = 66
-        }
     }
 }