macOS Tahoe Tab Bar

CodeEdit/Features/CodeEditUI/Views/GlassEffectView.swift

@@ -0,0 +1,37 @@
+//
+//  GlassEffectView.swift
+//  CodeEdit
+//
+//  Created by Khan Winter on 9/2/25.
+//
+
+import SwiftUI
+import AppKit
+
+struct GlassEffectView: NSViewRepresentable {
+    var tintColor: NSColor?
+
+    init(tintColor: NSColor? = nil) {
+        self.tintColor = tintColor
+    }
+
+    func makeNSView(context: Context) -> NSView {
+#if compiler(>=6.2)
+        if #available(macOS 26, *) {
+            let view = NSGlassEffectView()
+            view.cornerRadius = 0
+            view.tintColor = tintColor
+            return view
+        }
+#endif
+        return NSView()
+    }
+
+    func updateNSView(_ nsView: NSView, context: Context) {
+#if compiler(>=6.2)
+        if #available(macOS 26, *), let view = nsView as? NSGlassEffectView {
+            view.tintColor = tintColor
+        }
+#endif
+    }
+}

CodeEdit/Features/Editor/TabBar/Tabs/Tab/EditorTabBackground.swift

@@ -29,8 +29,11 @@ struct EditorTabBackground: View {
         ZStack {
             if isActive {
                 // Content background (visible if active)
-                EffectView(.contentBackground)
-                    .opacity(isActive ? 1 : 0)
+                if #available(macOS 26, *) {
+                    GlassEffectView()
+                } else {
+                    EffectView(.contentBackground)
+                }
 
                 // Accent color (visible if active)
                 Color(.controlAccentColor)

CodeEdit/Features/Editor/TabBar/Tabs/Tab/EditorTabCloseButton.swift

@@ -42,7 +42,11 @@ struct EditorTabCloseButton: View {
         .frame(width: buttonSize, height: buttonSize)
         .background(backgroundColor)
         .foregroundColor(isPressingClose ? .primary : .secondary)
-        .clipShape(RoundedRectangle(cornerRadius: 2))
+        .if(.tahoe) {
+            $0.clipShape(Circle())
+        } else: {
+            $0.clipShape(RoundedRectangle(cornerRadius: 2))
+        }
         .contentShape(Rectangle())
         .gesture(
             DragGesture(minimumDistance: 0)

CodeEdit/Features/Editor/TabBar/Tabs/Tab/EditorTabView.swift

@@ -122,10 +122,11 @@ struct EditorTabView: View {
 
     @ViewBuilder var content: some View {
         HStack(spacing: 0.0) {
-            EditorTabDivider()
-                .opacity(
-                    (isActive || inHoldingState) ? 0.0 : 1.0
-                )
+
+            if #unavailable(macOS 26) {
+                EditorTabDivider()
+                    .opacity((isActive || inHoldingState) ? 0.0 : 1.0)
+            }
             // Tab content (icon and text).
             HStack(alignment: .center, spacing: 3) {
                 Image(nsImage: tabFile.nsIcon)
@@ -165,14 +166,19 @@ struct EditorTabView: View {
                 }
                 .frame(maxWidth: .infinity, alignment: .leading)
             }
+            .if(.tahoe) {
+                $0.padding(.horizontal, 1.5)
+            }
             .opacity(
                 // Inactive states for tab bar item content.
                 activeState != .inactive
                 ? 1.0
                 : isActive ? 0.6 : 0.4
             )
-            EditorTabDivider()
-                .opacity((isActive || inHoldingState) ? 0.0 : 1.0)
+            if #unavailable(macOS 26) {
+                EditorTabDivider()
+                    .opacity((isActive || inHoldingState) ? 0.0 : 1.0)
+            }
         }
         .foregroundColor(
             isActive && isActiveEditor
@@ -220,6 +226,11 @@ struct EditorTabView: View {
                 EditorTabBackground(isActive: isActive, isPressing: isPressing, isDragging: isDragging)
                     .animation(.easeInOut(duration: 0.08), value: isHovering)
             }
+            .if(.tahoe) {
+                if #available(macOS 26, *) {
+                    $0.clipShape(Capsule()).clipped().containerShape(Capsule())
+                }
+            }
             // TODO: Enable the following code snippet when dragging-out behavior should be allowed.
             // Since we didn't handle the drop-outside event, dragging-out is disabled for now.
             //            .onDrag({

CodeEdit/Features/Editor/TabBar/Tabs/Views/EditorTabs.swift

@@ -260,6 +260,12 @@ struct EditorTabs: View {
                     ) {
                         ForEach(Array(openedTabs.enumerated()), id: \.element) { index, id in
                             if let item = editor.tabs.first(where: { $0.file.id == id }) {
+                                if index != 0
+                                    && editor.selectedTab?.file.id != id
+                                    && editor.selectedTab?.file.id != openedTabs[index - 1] {
+                                    EditorTabDivider()
+                                }
+
                                 EditorTabView(
                                     file: item.file,
                                     index: index,
@@ -293,6 +299,12 @@ struct EditorTabs: View {
                                         tabWidth: $tabWidth
                                     )
                                 )
+
+                                if index < openedTabs.count - 1
+                                    && editor.selectedTab?.file.id != id
+                                    && editor.selectedTab?.file.id != openedTabs[index + 1] {
+                                    EditorTabDivider()
+                                }
                             }
                         }
                     }
@@ -357,6 +369,19 @@ struct EditorTabs: View {
                 )
                 .opacity((scrollTrailingOffset ?? 0) <= 0 ? 0 : 1)
             }
+            .if(.tahoe) {
+                if #available(macOS 26.0, *) {
+                    // Unfortunate triple if here due to needing to compile on
+                    // earlier Xcodes.
+#if compiler(>=6.2)
+                    $0.background(GlassEffectView(tintColor: .tertiarySystemFill))
+                        .clipShape(Capsule())
+                        .clipped()
+#else
+                    $0
+#endif
+                }
+            }
         }
     }
 

CodeEdit/Features/Editor/Views/EditorAreaView.swift

@@ -30,6 +30,9 @@ struct EditorAreaView: View {
     @Environment(\.window.value)
     private var window: NSWindow?
 
+    @Environment(\.isEditorLayoutAtEdge)
+    private var isAtEdge
+
     init(editor: Editor, focus: FocusState<Editor?>.Binding) {
         self.editor = editor
         self._focus = focus
@@ -101,6 +104,10 @@ struct EditorAreaView: View {
                 }
 
                 VStack(spacing: 0) {
+                    if isAtEdge != .top, #available(macOS 26, *) {
+                        Spacer().frame(height: 4)
+                    }
+
                     if topSafeArea > 0 {
                         Rectangle()
                             .fill(.clear)
@@ -111,7 +118,9 @@ struct EditorAreaView: View {
                         EditorTabBarView(hasTopInsets: topSafeArea > 0, codeFile: fileBinding)
                             .id("TabBarView" + editor.id.uuidString)
                             .environmentObject(editor)
-                        Divider()
+                        if #unavailable(macOS 26) {
+                            Divider()
+                        }
                     }
                     if showEditorJumpBar {
                         EditorJumpBarView(
@@ -125,13 +134,47 @@ struct EditorAreaView: View {
                         }
                         .environmentObject(editor)
                         .padding(.top, shouldShowTabBar ? -1 : 0)
+                        if #unavailable(macOS 26) {
+                            Divider()
+                        }
+                    }
+                    // On Tahoe we only show one divider
+                    if #available(macOS 26, *), shouldShowTabBar || showEditorJumpBar {
                         Divider()
                     }
                 }
                 .environment(\.isActiveEditor, editor == editorManager.activeEditor)
                 .if(.tahoe) {
                     // FB20047271: Glass toolbar effect ignores floating scroll view views.
                     // https://openradar.appspot.com/radar?id=EhAKBVJhZGFyEICAgKbGmesJ
+
+                    // FB20191516: Can't disable backgrounded liquid glass tint
+                    // https://openradar.appspot.com/radar?id=EhAKBVJhZGFyEICAgLqTk-4J
+                    // Tracking Issue: #2191
+                    // Add this to the top:
+                    // ```
+                    // @AppSettings(\.theme.useThemeBackground)
+                    // var useThemeBackground
+                    //
+                    // private var backgroundColor: NSColor {
+                    //     let fallback = NSColor.textBackgroundColor
+                    //     return if useThemeBackground {
+                    //         ThemeModel.shared.selectedTheme?.editor.background.nsColor ?? fallback
+                    //     } else {
+                    //         fallback
+                    //     }
+                    // }
+                    // ```
+                    // And use this:
+                    // ```
+                    // $0.background(
+                    //    Rectangle().fill(.clear)
+                    //        .glassEffect(.regular.tint(Color(backgroundColor))
+                    //        .ignoresSafeArea(.all)
+                    // )
+                    // ```
+                    // When we can figure out how to disable the 'not focused' glass effect.
+
                     $0.background(EffectView(.headerView).ignoresSafeArea(.all))
                 } else: {
                     $0.background(EffectView(.headerView))

CodeEdit/Features/Editor/Views/EditorLayoutView.swift

@@ -15,7 +15,7 @@ struct EditorLayoutView: View {
     @Environment(\.window.value)
     private var window
 
-    @Environment(\.isAtEdge)
+    @Environment(\.isEditorLayoutAtEdge)
     private var isAtEdge
 
     var toolbarHeight: CGFloat {
@@ -63,7 +63,7 @@ struct EditorLayoutView: View {
         var splitView: some View {
             ForEach(Array(data.editorLayouts.enumerated()), id: \.offset) { index, item in
                 EditorLayoutView(layout: item, focus: $focus)
-                   .transformEnvironment(\.isAtEdge) { belowToolbar in
+                   .transformEnvironment(\.isEditorLayoutAtEdge) { belowToolbar in
                        calcIsAtEdge(current: &belowToolbar, index: index)
                    }
                    .environment(\.splitEditor) { [weak data] edge, newEditor in
@@ -87,12 +87,12 @@ struct EditorLayoutView: View {
     }
 }
 
-private struct BelowToolbarEnvironmentKey: EnvironmentKey {
+struct BelowToolbarEnvironmentKey: EnvironmentKey {
     static var defaultValue: VerticalEdge.Set = .all
 }
 
 extension EnvironmentValues {
-    fileprivate var isAtEdge: BelowToolbarEnvironmentKey.Value {
+    var isEditorLayoutAtEdge: BelowToolbarEnvironmentKey.Value {
         get { self[BelowToolbarEnvironmentKey.self] }
         set { self[BelowToolbarEnvironmentKey.self] = newValue }
     }

CodeEdit/Features/SplitView/Views/SplitViewControllerView.swift

@@ -96,6 +96,16 @@ final class SplitViewController: NSSplitViewController {
         override var dividerThickness: CGFloat {
             customDividerStyle.customThickness ?? super.dividerThickness
         }
+
+        override func drawDivider(in rect: NSRect) {
+            let safeRect = NSRect(
+                x: rect.origin.x,
+                y: max(rect.origin.y, safeAreaRect.origin.y),
+                width: isVertical ? dividerThickness : rect.width,
+                height: isVertical ? safeAreaRect.height : dividerThickness
+            )
+            super.drawDivider(in: safeRect)
+        }
     }
 
     var items: [SplitViewItem] = []