apple-hig-designer

// ✅ Content-focused
VStack(alignment: .leading, spacing: 8) {
    Text("Article Title")
        .font(.headline)
    Text("Article content goes here...")
        .font(.body)
        .foregroundColor(.secondary)
}
.padding()
 
// ❌ Distracting UI
VStack(spacing: 8) {
    Text("Article Title")
        .font(.headline)
        .foregroundColor(.white)
        .background(.blue)
        .border(.red, width: 3)
}

// ✅ Clear depth hierarchy
ZStack {
    Color(.systemBackground)
 
    VStack {
        // Card with elevation
        CardView()
            .shadow(radius: 8)
    }
}
 
// Using blur for depth
Text("Content")
    .background(.ultraThinMaterial)

NavigationStack {
    List {
        Text("Item 1")
        Text("Item 2")
    }
    .navigationTitle("Title")
    .navigationBarTitleDisplayMode(.large)
    .toolbar {
        ToolbarItem(placement: .navigationBarTrailing) {
            Button("Add") {
                // Action
            }
        }
    }
}

TabView {
    HomeView()
        .tabItem {
            Label("Home", systemImage: "house")
        }
 
    SearchView()
        .tabItem {
            Label("Search", systemImage: "magnifyingglass")
        }
 
    ProfileView()
        .tabItem {
            Label("Profile", systemImage: "person")
        }
}

List {
    Section("Today") {
        ForEach(items) { item in
            NavigationLink {
                DetailView(item: item)
            } label: {
                HStack {
                    Image(systemName: item.icon)
                        .foregroundColor(.accentColor)
                    Text(item.title)
                }
            }
        }
    }
}
.listStyle(.insetGrouped)

struct ContentView: View {
    @State private var showSheet = false
 
    var body: some View {
        Button("Show Details") {
            showSheet = true
        }
        .sheet(isPresented: $showSheet) {
            DetailView()
                .presentationDetents([.medium, .large])
        }
    }
}

// Filled button (primary action)
Button("Continue") {
    // Action
}
.buttonStyle(.borderedProminent)
 
// Bordered button (secondary action)
Button("Cancel") {
    // Action
}
.buttonStyle(.bordered)
 
// Plain button (tertiary action)
Button("Learn More") {
    // Action
}
.buttonStyle(.plain)

@State private var username = ""
@State private var password = ""
 
VStack(alignment: .leading, spacing: 16) {
    // Standard text field
    TextField("Username", text: $username)
        .textFieldStyle(.roundedBorder)
        .textContentType(.username)
        .textInputAutocapitalization(.never)
        .autocorrectionDisabled()
 
    // Secure field
    SecureField("Password", text: $password)
        .textFieldStyle(.roundedBorder)
        .textContentType(.password)
}

@State private var isEnabled = false
 
Toggle("Enable notifications", isOn: $isEnabled)
    .toggleStyle(.switch)

@State private var selectedSize = "Medium"
let sizes = ["Small", "Medium", "Large"]
 
// Menu style
Picker("Size", selection: $selectedSize) {
    ForEach(sizes, id: \.self) { size in
        Text(size).tag(size)
    }
}
.pickerStyle(.menu)
 
// Segmented style (for 2-5 options)
Picker("Size", selection: $selectedSize) {
    ForEach(sizes, id: \.self) { size in
        Text(size).tag(size)
    }
}
.pickerStyle(.segmented)

struct CardView: View {
    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Title")
                .font(.headline)
 
            Text("Description goes here with some details about the content.")
                .font(.subheadline)
                .foregroundColor(.secondary)
                .lineLimit(2)
 
            Spacer()
 
            Button("Action") {
                // Action
            }
            .buttonStyle(.borderedProminent)
        }
        .padding()
        .frame(width: 300, height: 200)
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(color: .black.opacity(0.1), radius: 8, x: 0, y: 4)
    }
}

// Dynamic Type text styles
Text("Large Title").font(.largeTitle)      // 34pt
Text("Title").font(.title)                 // 28pt
Text("Title 2").font(.title2)              // 22pt
Text("Title 3").font(.title3)              // 20pt
Text("Headline").font(.headline)           // 17pt semibold
Text("Body").font(.body)                   // 17pt regular
Text("Callout").font(.callout)             // 16pt
Text("Subheadline").font(.subheadline)     // 15pt
Text("Footnote").font(.footnote)           // 13pt
Text("Caption").font(.caption)             // 12pt
Text("Caption 2").font(.caption2)          // 11pt

// Custom font that scales with Dynamic Type
Text("Custom Text")
    .font(.custom("YourFont-Regular", size: 17, relativeTo: .body))

Text("Light").fontWeight(.light)
Text("Regular").fontWeight(.regular)
Text("Medium").fontWeight(.medium)
Text("Semibold").fontWeight(.semibold)
Text("Bold").fontWeight(.bold)
Text("Heavy").fontWeight(.heavy)

// UI Element Colors
Color(.label)                    // Primary text
Color(.secondaryLabel)           // Secondary text
Color(.tertiaryLabel)            // Tertiary text
Color(.quaternaryLabel)          // Watermark text
 
Color(.systemBackground)         // Primary background
Color(.secondarySystemBackground) // Secondary background
Color(.tertiarySystemBackground)  // Tertiary background
 
Color(.systemFill)               // Fill colors
Color(.secondarySystemFill)
Color(.tertiarySystemFill)
Color(.quaternarySystemFill)
 
Color(.separator)                // Separator lines
Color(.opaqueSeparator)          // Non-transparent separator

// Standard system colors (adapt to dark mode)
Color(.systemRed)
Color(.systemOrange)
Color(.systemYellow)
Color(.systemGreen)
Color(.systemMint)
Color(.systemTeal)
Color(.systemCyan)
Color(.systemBlue)
Color(.systemIndigo)
Color(.systemPurple)
Color(.systemPink)
Color(.systemBrown)
Color(.systemGray)

// Define adaptive color
extension Color {
    static let customBackground = Color("CustomBackground")
}
 
// In Assets.xcassets, create color set with:
// - Any Appearance: #FFFFFF
// - Dark Appearance: #000000

// Spacing values
.padding(8)      // 8pt
.padding(16)     // 16pt (standard)
.padding(24)     // 24pt
.padding(32)     // 32pt
.padding(40)     // 40pt
.padding(48)     // 48pt
 
// Edge-specific padding
.padding(.horizontal, 16)
.padding(.vertical, 24)
.padding(.top, 16)
.padding(.bottom, 16)

// Content within safe area (default)
VStack {
    Text("Content")
}
 
// Extend beyond safe area
VStack {
    Color.blue
}
.ignoresSafeArea()
 
// Extend top only
VStack {
    Color.blue
}
.ignoresSafeArea(edges: .top)

Button("Tap") {
    // Action
}
.frame(minWidth: 44, minHeight: 44)

// Component spacing
VStack(spacing: 8) {       // Tight spacing
    Text("Line 1")
    Text("Line 2")
}
 
VStack(spacing: 16) {      // Standard spacing
    Text("Section 1")
    Text("Section 2")
}
 
VStack(spacing: 24) {      // Loose spacing
    SectionView()
    SectionView()
}

// Accessible label
Image(systemName: "heart.fill")
    .accessibilityLabel("Favorite")
 
// Accessible value
Slider(value: $volume)
    .accessibilityLabel("Volume")
    .accessibilityValue("\(Int(volume * 100))%")
 
// Accessible hint
Button("Share") {
    share()
}
.accessibilityHint("Shares this item with others")
 
// Group elements
HStack {
    Image(systemName: "person")
    Text("John Doe")
}
.accessibilityElement(children: .combine)
 
// Hidden from VoiceOver
Image("decorative")
    .accessibilityHidden(true)

// Automatically supported with system fonts
Text("This text scales")
    .font(.body)
 
// Limit scaling (if necessary)
Text("This text has limits")
    .font(.body)
    .dynamicTypeSize(...DynamicTypeSize.xxxLarge)
 
// Custom font with Dynamic Type
Text("Custom font")
    .font(.custom("YourFont", size: 17, relativeTo: .body))

// Don't rely on color alone
HStack {
    Image(systemName: "checkmark.circle.fill")
        .foregroundColor(.green)
    Text("Success")
}
 
// Not just color
Circle()
    .fill(.green)
// ❌ Color only
 
// Better with shape/icon
HStack {
    Image(systemName: "checkmark.circle.fill")
    Circle().fill(.green)
}
// ✅ Color + shape

@Environment(\.accessibilityReduceMotion) var reduceMotion
 
var animation: Animation {
    reduceMotion ? .none : .spring()
}
 
Button("Animate") {
    withAnimation(animation) {
        // Animate
    }
}

@Environment(\.colorSchemeContrast) var contrast
 
var textColor: Color {
    contrast == .increased ? .primary : .secondary
}
 
Text("Content")
    .foregroundColor(textColor)

// Use semantic colors (automatic)
Color(.label)                // Adapts automatically
Color(.systemBackground)     // Adapts automatically

// Preview both modes
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
            .preferredColorScheme(.light)
 
        ContentView()
            .preferredColorScheme(.dark)
    }
}

// Basic symbol
Image(systemName: "heart")
 
// Colored symbol
Image(systemName: "heart.fill")
    .foregroundColor(.red)
 
// Sized symbol
Image(systemName: "heart")
    .imageScale(.large)
 
// Font-based sizing
Image(systemName: "heart")
    .font(.title)
 
// Multicolor symbols
Image(systemName: "person.crop.circle.fill.badge.checkmark")
    .symbolRenderingMode(.multicolor)
 
// Hierarchical rendering
Image(systemName: "heart.fill")
    .symbolRenderingMode(.hierarchical)
    .foregroundColor(.red)

iOS:
- 1024x1024 (App Store)
- 180x180 (iPhone @3x)
- 120x120 (iPhone @2x)
- 167x167 (iPad Pro)
- 152x152 (iPad @2x)

watchOS:
- 1024x1024 (App Store)
- 196x196 (49mm)
- 216x216 (45mm)

// Spring animation (natural, bouncy)
withAnimation(.spring()) {
    offset = 100
}
 
// Linear animation
withAnimation(.linear(duration: 0.3)) {
    opacity = 0
}
 
// Ease in/out
withAnimation(.easeInOut(duration: 0.3)) {
    scale = 1.2
}

@State private var offset = CGSize.zero
 
var body: some View {
    Circle()
        .offset(offset)
        .gesture(
            DragGesture()
                .onChanged { value in
                    offset = value.translation
                }
                .onEnded { _ in
                    withAnimation(.spring()) {
                        offset = .zero
                    }
                }
        )
}

struct LoadingView: View {
    var body: some View {
        VStack {
            ProgressView()
                .scaleEffect(1.5)
            Text("Loading...")
                .font(.caption)
                .foregroundColor(.secondary)
                .padding(.top)
        }
    }
}

struct ErrorView: View {
    let message: String
    let retry: () -> Void
 
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "exclamationmark.triangle")
                .font(.system(size: 48))
                .foregroundColor(.orange)
 
            Text("Something went wrong")
                .font(.headline)
 
            Text(message)
                .font(.subheadline)
                .foregroundColor(.secondary)
                .multilineTextAlignment(.center)
 
            Button("Try Again") {
                retry()
            }
            .buttonStyle(.borderedProminent)
        }
        .padding()
    }
}

struct EmptyStateView: View {
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "tray")
                .font(.system(size: 64))
                .foregroundColor(.secondary)
 
            Text("No Items")
                .font(.title2)
 
            Text("Your items will appear here")
                .font(.subheadline)
                .foregroundColor(.secondary)
 
            Button("Add Item") {
                // Action
            }
            .buttonStyle(.borderedProminent)
        }
    }
}