SKILL.md
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var body: some View {
if sizeClass == .regular {
TwoColumnLayout()
} else {
StackedLayout()
}
}}
### 1.2 Don't Scale Up iPhone UI
iPad layouts must be purpose-built. Stretching an iPhone layout across a 13" display wastes space and feels wrong. Use multi-column layouts, master-detail patterns, and increased information density in regular width.
### 1.3 Support All iPad Screen Sizes
Design for the full range: iPad Mini (8.3"), iPad (11"), iPad Air (11"/13"), and iPad Pro (11"/13"). Use flexible layouts that redistribute content rather than simply scaling.
### 1.4 Column-Based Layouts for Regular Width
In regular width, organize content into columns. Two-column is the most common (sidebar + detail). Three-column works for deep hierarchies (sidebar + list + detail). Avoid single-column full-width layouts on large screens.
struct ThreeColumnLayout: View {
var body: some View {
NavigationSplitView {
SidebarView()
} content: {
ContentListView()
} detail: {
DetailView()
}
}
}
### 1.5 Respect Safe Areas
iPad safe areas differ from iPhone. Older iPads have no home indicator. iPads in landscape have different insets than portrait. Always use `safeAreaInset` and never hardcode padding for notches or indicators.
### 1.6 Support Both Orientations
iPad apps must work well in both portrait and landscape. Landscape is the dominant orientation for productivity. Portrait is common for reading. Adapt column counts and layout density to orientation.
## 2. Multitasking (CRITICAL)
### 2.1 Support Split View
Your app must function correctly at 1/3, 1/2, and 2/3 screen widths in Split View. At 1/3 width, your app receives compact horizontal size class. Content must remain usable at every split ratio.
### 2.2 Support Slide Over
Slide Over presents your app as a compact-width overlay on the right edge. It behaves like an iPhone-width app. Ensure all functionality remains accessible in this narrow mode.
### 2.3 Handle Stage Manager
Stage Manager allows freely resizable windows and multiple windows simultaneously. Your app must:
- Resize fluidly to arbitrary dimensions
- Support multiple scenes (windows) showing different content
- Not assume any fixed size or aspect ratio
@main
struct MyApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
// Support multiple windows
WindowGroup("Detail", for: Item.ID.self) { $itemId in
DetailView(itemId: itemId)
}
}
}
### 2.4 Never Assume Full Screen
The app may launch directly into Split View or Stage Manager. Do not depend on full-screen dimensions during setup, onboarding, or any flow. Test your app at every possible size.
### 2.5 Handle Size Transitions Gracefully
When the user resizes via multitasking, animate layout changes smoothly. Preserve scroll position, selection state, and user context across size transitions. Never reload content on resize.
### 2.6 Support Multiple Scenes
Use `UIScene` / SwiftUI `WindowGroup` to let users open multiple instances of your app showing different content. Each scene is independent. Support `NSUserActivity` for state restoration.
## 3. Navigation (CRITICAL)
### 3.1 Sidebar for Primary Navigation
In regular width, replace the iPhone tab bar with a sidebar. The sidebar provides more room for navigation items, supports sections, and feels native on iPad.
struct AppNavigation: View {
@State private var selection: NavigationItem? = .inbox
var body: some View {
NavigationSplitView {
List(selection: $selection) {
Section("Main") {
Label("Inbox", systemImage: "tray")
.tag(NavigationItem.inbox)
Label("Drafts", systemImage: "doc")
.tag(NavigationItem.drafts)
Label("Sent", systemImage: "paperplane")
.tag(NavigationItem.sent)
}
Section("Labels") {
// Dynamic sections
}
}
.navigationTitle("Mail")
} detail: {
DetailView(for: selection)
}
}
}
### 3.2 Automatic Tab-to-Sidebar Conversion
SwiftUI `TabView` with `.sidebarAdaptable` style automatically converts to a sidebar in regular width. Use this for seamless iPhone-to-iPad adaptation.
TabView {
Tab("Home", systemImage: "house") { HomeView() }
Tab("Search", systemImage: "magnifyingglass") { SearchView() }
Tab("Profile", systemImage: "person") { ProfileView() }
}
.tabViewStyle(.sidebarAdaptable)
### 3.3 Three-Column Layout for Complex Hierarchies
Use `NavigationSplitView` with three columns when your information architecture has three levels: category > list > detail. Examples: mail (accounts > messages > message), file managers, settings.
### 3.4 Toolbar at Top
On iPad, toolbars live at the top of the screen in the navigation bar area, not at the bottom like iPhone. Place contextual actions in `.toolbar` with appropriate placement.
.toolbar {
ToolbarItemGroup(placement: .primaryAction) {
Button("Compose", systemImage: "square.and.pencil") { }
}
ToolbarItemGroup(placement: .secondaryAction) {
Button("Archive", systemImage: "archivebox") { }
Button("Delete", systemImage: "trash") { }
}
}
### 3.5 Detail View Should Never Be Empty
When no item is selected in a list/sidebar, show a meaningful empty state in the detail area. Use a placeholder with icon and instruction text, not a blank screen.
### 3.6 Reduce Recall in Large-Canvas Navigation
Keep sidebar selection, search terms, and disclosure state visible and preserved across size changes and scene switches. In multi-column layouts, users should resume from structure on screen, not from memory.
## 4. Pointer & Trackpad (HIGH)
### 4.1 Add Hover Effects to Interactive Elements
All tappable elements should respond to pointer hover. The system provides automatic hover effects for standard controls. For custom views, use `.hoverEffect()`.
Button("Action") { }
.hoverEffect(.highlight) // Subtle highlight on hover
// Custom hover effect
MyCustomView()
.hoverEffect(.lift) // Lifts and adds shadow
### 4.2 Pointer Magnetism on Buttons
The pointer should snap to (be attracted toward) button bounds. Standard UIKit/SwiftUI buttons get this automatically. For custom hit targets, ensure the pointer region matches the tappable area using `.contentShape()`.
### 4.3 Support Right-Click Context Menus
Right-click (secondary click) should present context menus. Use `.contextMenu` which automatically supports both long-press (touch) and right-click (pointer).
Text(item.title)
.contextMenu {
Button("Copy", systemImage: "doc.on.doc") { }
Button("Share", systemImage: "square.and.arrow.up") { }
Divider()
Button("Delete", systemImage: "trash", role: .destructive) { }
}
### 4.4 Trackpad Scroll Behaviors
Support two-finger scrolling with momentum. Pinch to zoom where appropriate. Respect scroll direction preferences. For custom scroll views, ensure trackpad gestures feel natural alongside touch gestures.
### 4.5 Customize Cursor for Content Areas
Change cursor appearance based on context. Text areas show I-beam. Links show pointer hand. Resize handles show resize cursors. Draggable items show grab cursor.
### 4.6 Pointer-Driven Drag and Drop
Pointer users expect click-and-drag for rearranging, selecting, and moving content. Combine with multi-select via Shift-click and Cmd-click.
## 5. Keyboard (HIGH)
### 5.1 Cmd+Key Shortcuts for All Major Actions
Every primary action must have a keyboard shortcut. Standard shortcuts are mandatory:
Shortcut
Action
Cmd+N
New item
Cmd+F
Find/Search
Cmd+S
Save
Cmd+Z
Undo
Cmd+Shift+Z
Redo
Cmd+C/V/X
Copy/Paste/Cut
Cmd+A
Select all
Cmd+P
Print
Cmd+W
Close window/tab
Cmd+,
Settings/Preferences
Delete
Delete selected item
Button("New Document") { createDocument() }
.keyboardShortcut("n", modifiers: .command)
### 5.2 Discoverability via Cmd-Hold Overlay
When the user holds the Cmd key, iPadOS shows a shortcut overlay. Register all shortcuts using `.keyboardShortcut()` so they appear in this overlay. Group related shortcuts logically.
### 5.3 Tab Key Navigation Between Fields
Support Tab to move forward and Shift+Tab to move backward between form fields and focusable elements. Use `.focusable()` and `@FocusState` to manage keyboard focus order.
struct FormView: View {
@FocusState private var focusedField: Field?
var body: some View {
Form {
TextField("Name", text: $name)
.focused($focusedField, equals: .name)
TextField("Email", text: $email)
.focused($focusedField, equals: .email)
TextField("Phone", text: $phone)
.focused($focusedField, equals: .phone)
}
}
}
### 5.4 Never Override System Shortcuts
Do not claim shortcuts reserved by the system: Cmd+H (Home), Cmd+Tab (App Switcher), Cmd+Space (Spotlight), Globe key combinations. These will not work and create confusion.
### 5.5 Detect Hardware Keyboard
Adapt UI when a hardware keyboard is connected. Hide the on-screen keyboard shortcut bar. Show keyboard-optimized controls. Use `GCKeyboard` or track keyboard visibility to detect state.
### 5.6 Arrow Key Navigation
Support arrow keys for navigating lists, grids, and collections. Combine with Shift for multi-selection. This is essential for productivity-focused apps.
### 5.7 Shortcuts Must Be Discoverable
Do not rely on users memorizing shortcut vocabularies. Expose commands through the Cmd-hold overlay, menu labels, and visible focus movement so people learn shortcuts by recognition and repetition.
## 6. Apple Pencil (MEDIUM)
### 6.1 Support Scribble
iPadOS converts handwriting to text in any standard text field automatically. Do not disable Scribble. For custom text input, adopt `UIScribbleInteraction`. Test that Scribble works in all text entry points.
### 6.2 Double-Tap Tool Switching
Apple Pencil 2 and later supports double-tap to switch tools (e.g., pen to eraser). If your app has drawing tools, implement the `UIPencilInteraction` delegate to handle double-tap.
### 6.3 Pressure and Tilt for Drawing
For drawing apps, respond to `force` (pressure) and `altitudeAngle`/`azimuthAngle` (tilt) from pencil touch events. Use these for variable line width, opacity, or shading.
### 6.4 Hover Detection (M2+ Pencil)
Apple Pencil with hover (M2 iPad Pro and later) provides position data before the pencil touches the screen. Use this for preview effects, tool size indicators, and enhanced precision.
// UIKit hover support via UIHoverGestureRecognizer
let hoverRecognizer = UIHoverGestureRecognizer(target: self, action: #selector(pencilHoverChanged(_:)))
hoverRecognizer.allowedTouchTypes = [NSNumber(value: UITouch.TouchType.pencil.rawValue)]
canvas.addGestureRecognizer(hoverRecognizer)
@objc func pencilHoverChanged(_ hover: UIHoverGestureRecognizer) {
let location = hover.location(in: canvas)
showBrushPreview(at: location)
}
### 6.5 PencilKit Integration
For note-taking and annotation, use `PKCanvasView` from PencilKit. It provides a full drawing experience with tool picker, undo, and ink recognition out of the box.
import PencilKit
struct DrawingView: UIViewRepresentable {
@Binding var canvasView: PKCanvasView
func makeUIView(context: Context) -> PKCanvasView {
canvasView.tool = PKInkingTool(.pen, color: .black, width: 5)
canvasView.drawingPolicy = .anyInput
return canvasView
}
}
## 7. Drag and Drop (HIGH)
### 7.1 Inter-App Drag and Drop is Expected
iPad users expect to drag content between apps. Support dragging content out (as a source) and dropping content in (as a destination). This is a core iPad interaction.
// As drag source
Text(item.title)
.draggable(item.title)
// As drop destination
DropTarget()
.dropDestination(for: String.self) { items, location in
handleDrop(items)
return true
}
### 7.2 Multi-Item Drag
Users can pick up one item, then tap additional items to add them to the drag. Support multi-item drag by providing multiple `NSItemProvider` items. Show a badge count on the drag preview.
### 7.3 Spring-Loaded Interactions
When dragging over a navigation element (folder, tab, sidebar item), pause briefly to "spring open" that destination. Implement spring-loading on navigation containers to enable deep drop targets.
### 7.4 Visual Feedback for Drag and Drop
Provide clear visual states:
- **Lift**: Item lifts with shadow when drag begins
- **Move**: Destination highlights when drag hovers over valid target
- **Drop**: Animate insertion at drop point
- **Cancel**: Item animates back to origin
### 7.5 Support Universal Control
Universal Control lets users drag between iPad and Mac. If your app supports drag and drop with standard `NSItemProvider` and UTTypes, Universal Control works automatically.
### 7.6 Drop Delegates for Custom Behavior
Use `DropDelegate` for fine-grained control over drop behavior: validating drop content, reordering within lists, and handling drop position.
struct ReorderDropDelegate: DropDelegate {
let item: Item
@Binding var items: [Item]
@Binding var draggedItem: Item?
func performDrop(info: DropInfo) -> Bool {
draggedItem = nil
return true
}
func dropEntered(info: DropInfo) {
guard let draggedItem,
let fromIndex = items.firstIndex(of: draggedItem),
let toIndex = items.firstIndex(of: item) else { return }
withAnimation {
items.move(fromOffsets: IndexSet(integer: fromIndex),
toOffset: toIndex > fromIndex ? toIndex + 1 : toIndex)
}
}
}
## 8. External Display (MEDIUM)
### 8.1 Provide Extended Content, Not Just Mirroring
When connected to an external display, show complementary content rather than duplicating the iPad screen. Presentations, reference material, or expanded views belong on the external display while controls stay on iPad.
@main
struct MyApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
// Additional scene for external display
WindowGroup(id: "presentation") {
PresentationView()
}
}
}
### 8.2 Handle Display Connection and Disconnection
Observe external display lifecycle via `UIWindowScene` events in your `SceneDelegate` or by listening for `UIScene` session notifications (`UIApplication.didConnectSceneSessionNotification` / `UIApplication.didDisconnectSceneSessionNotification`). Transition gracefully — if the external display disconnects mid-presentation, bring content back to the iPad screen without data loss.
// SceneDelegate: detect when a scene (external display window) connects or disconnects
func scene(_ scene: UIScene,
willConnectTo session: UISceneSession,
options connectionOptions: UIScene.ConnectionOptions) {
guard let windowScene = scene as? UIWindowScene else { return }
configureExternalDisplay(for: windowScene)
}
func sceneDidDisconnect(_ scene: UIScene) {
restoreContentToiPad()
}
### 8.3 Support Full External Display Resolution
Use the full resolution and aspect ratio of the external display. Do not letterbox or pillarbox your content. In iOS 16+ multi-scene contexts, `UIScreen.main` is deprecated — query the connected display via `UIWindowScene.coordinateSpace.bounds` and `UIWindowScene.screen.scale`, or use `@Environment(\.displayScale)` in SwiftUI.
## 9. Accessibility (CRITICAL)
**Impact:** CRITICAL
### Rule 9.1: VoiceOver Labels on All Interactive Elements
Every button, control, and interactive element must have a meaningful accessibility label. Icon-only toolbar items and custom views must use `.accessibilityLabel()`.
**Correct:**
Button(action: compose) {
Image(systemName: "square.and.pencil")
}
.accessibilityLabel("Compose new message")
**Incorrect:**
Button(action: compose) {
Image(systemName: "square.and.pencil")
}
// VoiceOver reads "square.and.pencil" — meaningless to users
### Rule 9.2: Support Dynamic Type Including Accessibility Sizes
Use semantic text styles (`title`, `body`, `caption`) so text scales with the user's preferred size. In iPad's larger canvas, never clamp text size or disable scaling. Test up to the five accessibility size steps.
Text("Section Header")
.font(.headline) // Scales with Dynamic Type automatically
### Rule 9.3: Pointer Accessibility — Hover Must Not Be the Only Cue
Hover states (`.hoverEffect`) enhance pointer input but must not be the sole indicator of interactivity. Ensure all interactive elements are also distinguishable via color, shape, or label for VoiceOver and keyboard-only users.
### Rule 9.4: Full Keyboard Access and Focus Routing
With Full Keyboard Access enabled, Tab must move focus through all interactive elements in logical order. In Split View and multi-window layouts, focus must not escape to a hidden or occluded window. Use `@FocusState` and `.focusable()` to control the keyboard focus graph.
struct FormView: View {
@FocusState private var focusedField: Field?
var body: some View {
VStack {
TextField("Name", text: $name)
.focused($focusedField, equals: .name)
TextField("Email", text: $email)
.focused($focusedField, equals: .email)
}
}
}
### Rule 9.5: VoiceOver in Split View — Separate Focus Contexts
In Split View, each app has its own VoiceOver focus context. Your app must not assume it occupies the full screen. Ensure VoiceOver can navigate your entire visible interface even at 1/3 or 1/2 split width. Do not hide actionable content outside the visible region without also removing it from the accessibility tree.
### Rule 9.6: Respond to Bold Text
When the user enables Bold Text in Settings, custom-rendered text must adapt. SwiftUI text styles handle this automatically. UIKit code must check `UIAccessibility.isBoldTextEnabled` or use `@Environment(\.legibilityWeight)` in SwiftUI.
**Correct:**
// SwiftUI — handled automatically for standard text styles
Text("Section Header")
.font(.headline)
// SwiftUI — custom rendering respects legibilityWeight
@Environment(\.legibilityWeight) var legibilityWeight
var body: some View {
Text("Custom Label")
.fontWeight(legibilityWeight == .bold ? .bold : .regular)
}
**Incorrect:**
// Hardcoded weight ignores Bold Text preference
label.font = UIFont.systemFont(ofSize: 17, weight: .regular)
// Missing: re-query font when UIAccessibility.boldTextStatusDidChangeNotification fires
### Rule 9.7: Respond to Increase Contrast
When the user enables Increase Contrast in Settings, custom colors must provide higher-contrast variants. Use `@Environment(\.colorSchemeContrast)` in SwiftUI or `UIAccessibility.isDarkerSystemColorsEnabled` in UIKit.
**Correct:**
// SwiftUI
@Environment(\.colorSchemeContrast) var contrast
var separatorColor: Color {
contrast == .increased ? Color.primary : Color.secondary
}
// UIKit
let useHighContrast = UIAccessibility.isDarkerSystemColorsEnabled
let borderColor: UIColor = useHighContrast ? .label : .separator
**Incorrect:**
// Static color ignores Increase Contrast setting
let borderColor = UIColor.separator // Always low-contrast; ignores user preference