rtl support for divtabs (ios)

client/ios/DivKit/Extensions/DivTabsExtensions.swift

@@ -44,6 +44,7 @@ extension DivTabs: DivBlockModeling {
         expressionResolver: expressionResolver,
         context: context
       ),
+      layoutDirection: context.layoutDirection,
       listPaddings: titlePaddings.makeEdgeInsets(context: context)
     )
 
@@ -53,7 +54,8 @@ extension DivTabs: DivBlockModeling {
         ? .bySelectedPage
         : .byHighestPage,
       path: tabsContext.parentPath,
-      scrollingEnabled: resolveSwitchTabsByContentSwipeEnabled(expressionResolver)
+      scrollingEnabled: resolveSwitchTabsByContentSwipeEnabled(expressionResolver),
+      layoutDirection: context.layoutDirection
     )
 
     return try TabsBlock(

client/ios/LayoutKit/LayoutKit/UI/Views/TabbedPages/TabContentsView.swift

@@ -88,6 +88,11 @@ internal class TabContentsView: BlockView {
     self.observer = observer
     self.overscrollDelegate = overscrollDelegate
 
+    if oldModel?.layoutDirection != model.layoutDirection {
+      collectionView.semanticContentAttribute = model
+        .layoutDirection == .rightToLeft ? .forceRightToLeft : .forceLeftToRight
+    }
+
     if oldModel == nil || oldModel.pages !== model.pages || oldObserver !== observer {
       dataSource.models = [model.pages.map { $0.block as! CollectionCellModel }]
 

client/ios/LayoutKit/LayoutKit/UI/Views/TabbedPages/TabListSelectionDataSourceImpl.swift

@@ -46,6 +46,7 @@ final class TabListSelectionDataSourceImpl: TabListSelectionDataSource {
 
     return TabTitlesViewModel(
       items: items,
+      layoutDirection: listModel.layoutDirection,
       listPaddings: listModel.listPaddings,
       titlePaddings: listModel.titleStyle.paddings,
       selectedBackgroundColor: listModel.titleStyle.activeBackgroundColor,

client/ios/LayoutKit/LayoutKit/UI/Views/TabbedPages/TabListView.swift

@@ -5,7 +5,7 @@ import CommonCorePublic
 final class TabListView: UIView {
   private let collectionView: UICollectionView
   private let delegate: TabListViewDelegate
-  private let collectionViewLayout = UICollectionViewFlowLayout.make()
+  private let collectionViewLayout = GenericCollectionViewFlowLayout.make()
 
   private var selectedItemBackground: UIView!
   var isMovingToSelectedItem = false
@@ -23,6 +23,11 @@ final class TabListView: UIView {
         dataSource = TabListViewDataSource(tabs: model.items)
         delegate.tabs = model.items
       }
+      if oldValue?.layoutDirection != model.layoutDirection {
+        collectionView.semanticContentAttribute = model
+          .layoutDirection == .rightToLeft ? .forceRightToLeft : .forceLeftToRight
+        delegate.layoutDirection = model.layoutDirection
+      }
       collectionViewLayout.sectionInset = model.listPaddings
       collectionViewLayout.minimumLineSpacing = model.itemSpacing ?? 0
       selectedItemBackground.backgroundColor = model.selectedBackgroundColor.systemColor
@@ -205,14 +210,18 @@ private struct AnimationInfo {
   }
 }
 
-extension UICollectionViewFlowLayout {
-  fileprivate static func make() -> UICollectionViewFlowLayout {
-    let flowLayout = UICollectionViewFlowLayout()
+final class GenericCollectionViewFlowLayout: UICollectionViewFlowLayout {
+  fileprivate static func make() -> GenericCollectionViewFlowLayout {
+    let flowLayout = GenericCollectionViewFlowLayout()
     flowLayout.scrollDirection = .horizontal
     flowLayout.minimumLineSpacing = 0
     flowLayout.minimumInteritemSpacing = 0
     return flowLayout
   }
+
+  override var flipsHorizontallyInOppositeLayoutDirection: Bool {
+    true
+  }
 }
 
 private func makeCollectionView(layout: UICollectionViewLayout) -> UICollectionView {

client/ios/LayoutKit/LayoutKit/UI/Views/TabbedPages/TabListViewDelegate.swift

@@ -5,6 +5,7 @@ import LayoutKitInterface
 
 final class TabListViewDelegate: NSObject, UICollectionViewDelegateFlowLayout {
   private let collectionView: UICollectionView
+  public var layoutDirection: UserInterfaceLayoutDirection = .leftToRight
 
   private var itemSizes: [CGSize] = [] {
     didSet {
@@ -66,7 +67,7 @@ final class TabListViewDelegate: NSObject, UICollectionViewDelegateFlowLayout {
     let nextItemVisibilityFraction = itemSelection - CGFloat(baseItemIndex)
 
     let contentOffsetX: CGFloat
-    let pillOriginX: CGFloat
+    var pillOriginX: CGFloat
 
     let bouncingLeft = itemSelection <= 0
     let bouncingRight = itemSelection >= CGFloat(tabs.count - 1)
@@ -94,6 +95,11 @@ final class TabListViewDelegate: NSObject, UICollectionViewDelegateFlowLayout {
       pillOriginX = originX.interpolated(to: nextOriginX, progress: nextItemVisibilityFraction)
     }
 
+    if layoutDirection == .rightToLeft {
+      let pillSizeWidth = itemSizes.map { $0.width }.interim(at: itemSelection)
+      pillOriginX = size.width - pillSizeWidth - pillOriginX
+    }
+
     if let offset = offset {
       return Layout(
         contentOffset: CGPoint(x: offset, y: 0),

client/ios/LayoutKit/LayoutKit/UI/Views/TabbedPages/TabTitlesViewModel.swift

@@ -4,6 +4,7 @@ import CommonCorePublic
 
 struct TabTitlesViewModel {
   let items: [TabTitleViewModel]
+  let layoutDirection: UserInterfaceLayoutDirection
   let listPaddings: EdgeInsets
   let titlePaddings: EdgeInsets
   let selectedBackgroundColor: Color

client/ios/LayoutKit/LayoutKit/ViewModels/TabbedPages/TabContentsViewModel.swift

@@ -11,6 +11,7 @@ public struct TabContentsViewModel: Equatable {
   public let footer: Block?
   public let scrollingEnabled: Bool
   public let contentInsets: EdgeInsets
+  public let layoutDirection: UserInterfaceLayoutDirection
 
   public init(
     pages: [TabPageViewModel],
@@ -19,7 +20,8 @@ public struct TabContentsViewModel: Equatable {
     path: UIElementPath? = nil,
     background: Background? = nil,
     footer: Block? = nil,
-    scrollingEnabled: Bool = true
+    scrollingEnabled: Bool = true,
+    layoutDirection: UserInterfaceLayoutDirection = .leftToRight
   ) throws {
     self.path = path
     self.pages = pages
@@ -28,6 +30,7 @@ public struct TabContentsViewModel: Equatable {
     self.background = background
     self.footer = footer
     self.scrollingEnabled = scrollingEnabled
+    self.layoutDirection = layoutDirection
 
     try checkConstraints()
   }

client/ios/LayoutKit/LayoutKit/ViewModels/TabbedPages/TabListViewModel.swift

@@ -8,6 +8,7 @@ public final class TabListViewModel: Equatable {
 
   public let tabTitles: [UILink]
   public let titleStyle: TabTitleStyle
+  public let layoutDirection: UserInterfaceLayoutDirection
   public let listPaddings: EdgeInsets
 
   lazy var tabs: [TabTitleViewModel] = tabTitles.map { item in
@@ -27,10 +28,12 @@ public final class TabListViewModel: Equatable {
   public init(
     tabTitles: [UILink],
     titleStyle: TabTitleStyle = TabTitleStyle(),
+    layoutDirection: UserInterfaceLayoutDirection = .leftToRight,
     listPaddings: EdgeInsets = defaultListPaddings
   ) {
     self.tabTitles = tabTitles
     self.titleStyle = titleStyle
+    self.layoutDirection = layoutDirection
     self.listPaddings = listPaddings
   }
 

client/ios/LayoutKit/LayoutKit/ViewModels/TabbedPages/TabViewModel.swift

@@ -49,7 +49,8 @@ extension TabContentsViewModel {
       path: path,
       background: background,
       footer: footer,
-      scrollingEnabled: scrollingEnabled
+      scrollingEnabled: scrollingEnabled,
+      layoutDirection: layoutDirection
     )
   }
 }