Add item group

Package.swift

@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
   name: "UIPreview",
   platforms: [
-    .iOS(.v13)
+    .iOS(.v11)
   ],
   products: [
     // Products define the executables and libraries a package produces, and make them visible to other packages.

Sources/UIPreview/UICatalog/GroupItem.swift

@@ -0,0 +1,39 @@
+#if canImport(SwiftUI)
+import SwiftUI
+#endif
+
+@available(iOS 13, *)
+struct GroupItem: View {
+  typealias Element = (title: String, builder: () -> AnyView)
+
+  let items: [Element]
+
+  var body: some View {
+    VStack {
+      ForEach(items, id: \.title) { item in
+        Group {
+          Text(item.title)
+            .font(.headline)
+            .fontWeight(.bold)
+          Divider()
+          item.builder()
+            .frame(maxWidth: .infinity)
+        }
+      }.padding(.bottom, 10)
+    }
+  }
+}
+
+#if DEBUG
+@available(iOS 13, *)
+struct GroupItem_Previews: PreviewProvider {
+  static var previews: some View {
+    ScrollView {
+      GroupItem(items: [
+        ("Group 1", { AnyView(Text("Preview")) } ),
+        ("Group 2", { AnyView(Image(systemName: "square.and.pencil")) } )
+      ])
+    }
+  }
+}
+#endif

Sources/UIPreview/UICatalog/PreviewDescriptor.swift

@@ -29,6 +29,21 @@ public extension UICatalog.PreviewDescriptor {
                 title: String? = nil) where Content: UIViewCatalogPresentable {
     id = "\(content)"
     self.title = title ?? "\(content)"
-    self.builder = { AnyView(CatalogItem<Content>(configuration: configuration)) }
+    builder = { AnyView(CatalogItem<Content>(configuration: configuration)) }
+  }
+
+  init(_ content: UICatalog.PreviewDescriptor...,
+       configuration: UICatalog.PreviewConfiguration = .init(),
+       title: String? = nil) {
+    self.init(content, configuration: configuration, title: title)
+  }
+
+  init(_ content: [UICatalog.PreviewDescriptor],
+       configuration: UICatalog.PreviewConfiguration = .init(),
+       title: String? = nil) {
+    id = content.map(\.id).joined()
+    self.title = title ?? content.map(\.title).joined(separator: " ")
+    let items: [GroupItem.Element] = content.map {  ($0.title, $0.builder) }
+    builder = { AnyView(GroupItem(items: items)) }
   }
 }