macos-hig-designer

What this skill does

# macOS HIG Designer

Design native macOS applications following Apple's Human Interface Guidelines with macOS Tahoe's Liquid Glass design system.

## Workflow Decision Tree

```
User Request
    │
    ├─► "Review my macOS UI code"
    │       └─► Run HIG Compliance Check (Section 11)
    │           └─► Report violations with fixes
    │
    ├─► "Modernize this macOS code"
    │       └─► Identify deprecated APIs
    │           └─► Apply Modern API Replacements (Section 10)
    │
    └─► "Build [feature] for macOS"
            └─► Design with HIG principles first
                └─► Implement with modern SwiftUI patterns
```

## 1. Design Principles (macOS Tahoe)

### Three Core Tenets

| Principle | Description | Implementation |
|-----------|-------------|----------------|
| **Hierarchy** | Visual layers through Liquid Glass translucency | Use `.glassEffect()`, materials, and depth |
| **Harmony** | Concentric alignment between hardware/software | Round corners, consistent radii, flowing shapes |
| **Consistency** | Platform conventions that adapt to context | Follow standard patterns, respect user preferences |

### Liquid Glass Philosophy

Liquid Glass combines transparency, reflection, refraction, and fluidity with a frosted aesthetic:

```swift
// macOS Tahoe Liquid Glass effect
.glassEffect()                    // Primary Liquid Glass material
.glassEffect(.regular.tinted)     // Tinted variant (26.1+)

// Pre-Tahoe fallback
.background(.ultraThinMaterial)
.background(.regularMaterial)
.background(.thickMaterial)
```

**When to use Liquid Glass:**
- Sidebars, toolbars, and navigation chrome
- Floating panels and popovers
- Dock and widget backgrounds
- System-level UI elements

**When NOT to use:**
- Primary content areas (documents, media)
- Dense data displays (tables, lists with many items)
- Text-heavy interfaces where readability is critical

## 2. Navigation Patterns

### NavigationSplitView (Primary Pattern)

Three-column layout for document-based and content-heavy apps:

```swift
struct ContentView: View {
    @State private var selection: Item.ID?
    @State private var columnVisibility: NavigationSplitViewVisibility = .all

    var body: some View {
        NavigationSplitView(columnVisibility: $columnVisibility) {
            // Sidebar (source list)
            List(items, selection: $selection) { item in
                NavigationLink(value: item) {
                    Label(item.title, systemImage: item.icon)
                }
            }
            .navigationSplitViewColumnWidth(min: 180, ideal: 220, max: 300)
        } content: {
            // Content column (optional middle)
            ContentListView(selection: selection)
        } detail: {
            // Detail view
            DetailView(item: selectedItem)
        }
    }
}
```

### Sidebar Patterns

```swift
// Source list with sections
List(selection: $selection) {
    Section("Library") {
        ForEach(libraryItems) { item in
            Label(item.name, systemImage: item.icon)
                .tag(item)
        }
    }

    Section("Collections") {
        ForEach(collections) { collection in
            Label(collection.name, systemImage: "folder")
                .tag(collection)
                .badge(collection.count)
        }
    }
}
.listStyle(.sidebar)
```

### Inspector Panel (Trailing Sidebar)

```swift
struct DocumentView: View {
    @State private var showInspector = true

    var body: some View {
        MainContentView()
            .inspector(isPresented: $showInspector) {
                InspectorView()
                    .inspectorColumnWidth(min: 200, ideal: 250, max: 400)
            }
            .toolbar {
                ToolbarItem {
                    Button {
                        showInspector.toggle()
                    } label: {
                        Label("Inspector", systemImage: "sidebar.trailing")
                    }
                }
            }
    }
}
```

## 3. Window Management

### Window Configuration

```swift
@main
struct MyApp: App {
    var body: some Scene {
        // Main document window
        WindowGroup {
            ContentView()
        }
        .windowStyle(.automatic)
        .windowToolbarStyle(.unified)
        .defaultSize(width: 900, height: 600)
        .defaultPosition(.center)

        // Settings window
        Settings {
            SettingsView()
        }

        // Utility window
        Window("Inspector", id: "inspector") {
            InspectorWindow()
        }
        .windowStyle(.plain)
        .windowResizability(.contentSize)
        .defaultPosition(.topTrailing)

        // Menu bar extra
        MenuBarExtra("Status", systemImage: "circle.fill") {
            StatusMenu()
        }
        .menuBarExtraStyle(.window)
    }
}
```

### Window Styles

| Style | Use Case |
|-------|----------|
| `.automatic` | Standard app windows |
| `.hiddenTitleBar` | Content-focused (media players) |
| `.plain` | Utility windows, panels |
| `.unified` | Integrated toolbar appearance |
| `.unifiedCompact` | Compact toolbar height |

### Window State Restoration

```swift
WindowGroup {
    ContentView()
}
.handlesExternalEvents(matching: Set(arrayLiteral: "main"))
.commands {
    CommandGroup(replacing: .newItem) {
        Button("New Document") {
            // Handle new document
        }
        .keyboardShortcut("n")
    }
}
```

### Document-Based Apps

```swift
@main
struct DocumentApp: App {
    var body: some Scene {
        DocumentGroup(newDocument: MyDocument()) { file in
            DocumentView(document: file.$document)
        }
        .commands {
            CommandGroup(after: .saveItem) {
                Button("Export...") { }
                    .keyboardShortcut("e", modifiers: [.command, .shift])
            }
        }
    }
}

struct MyDocument: FileDocument {
    static var readableContentTypes: [UTType] { [.plainText] }

    init(configuration: ReadConfiguration) throws { }
    func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper { }
}
```

## 4. Toolbar & Menu Bar

### Toolbar Configuration

```swift
.toolbar {
    // Leading items (macOS places these before title)
    ToolbarItem(placement: .navigation) {
        Button(action: goBack) {
            Label("Back", systemImage: "chevron.left")
        }
    }

    // Principal (centered)
    ToolbarItem(placement: .principal) {
        Picker("View Mode", selection: $viewMode) {
            Label("Icons", systemImage: "square.grid.2x2").tag(ViewMode.icons)
            Label("List", systemImage: "list.bullet").tag(ViewMode.list)
        }
        .pickerStyle(.segmented)
    }

    // Trailing items
    ToolbarItemGroup(placement: .primaryAction) {
        Button(action: share) {
            Label("Share", systemImage: "square.and.arrow.up")
        }

        Button(action: toggleInspector) {
            Label("Inspector", systemImage: "sidebar.trailing")
        }
    }
}
.toolbarRole(.editor) // or .browser, .automatic
```

### Custom Menu Bar

```swift
.commands {
    // Replace existing menu group
    CommandGroup(replacing: .newItem) {
        Button("New Project") { }
            .keyboardShortcut("n")
        Button("New from Template...") { }
            .keyboardShortcut("n", modifiers: [.command, .shift])
    }

    // Add to existing group
    CommandGroup(after: .sidebar) {
        Button("Toggle Inspector") { }
            .keyboardShortcut("i", modifiers: [.command, .option])
    }

    // Custom menu
    CommandMenu("Canvas") {
        Button("Zoom In") { }
            .keyboardShortcut("+")
        Button("Zoom Out") { }
            .keyboardShortcut("-")
        Divider()
        Button("Fit to Window") { }
            .keyboardShortcut("0")
    }
}
```

### Menu Bar Apps

```swift
MenuBarExtra("App Status", systemImage: statusIcon) {
    VStack(alignment: .leading, spacing: 8) {
        Text("Status: \(status)")
            .font(.headline)

        Divider()