[WIP] Tune catalog item

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/CatalogItem.swift

@@ -0,0 +1,33 @@
+#if canImport(SwiftUI)
+import SwiftUI
+#endif
+
+@available(iOS 13, *)
+struct CatalogItem<Content: UIViewCatalogPresentable>: View {
+  let configuration: UICatalog.PreviewConfiguration
+
+  var body: some View {
+    ForEach(values: Content.previewModels) { model in
+      ForEach(values: configuration.colorSchemes) { scheme in
+        item(model: model, scheme: scheme)
+      }
+    }
+  }
+
+  func item(model: Content.PreviewModel,
+            scheme: ColorScheme) -> some View {
+    VStack(alignment: .center, spacing: 12.0) {
+      Text("\(scheme.previewName):  \(String(describing: model))")
+        .font(.subheadline)
+        .fontWeight(.bold)
+      Content.preview(with: model)
+        .frame(maxWidth: .infinity)
+//        .previewLayout(.sizeThatFits)
+        .background(Color(.systemBackground))
+        .colorScheme(scheme)
+      Divider()
+
+    }
+    .padding()
+  }
+}

Sources/UIPreview/CatalogPage.swift

@@ -1,47 +0,0 @@
-#if canImport(SwiftUI)
-import SwiftUI
-#endif
-import UIKit
-
-@available(iOS 13, *)
-struct CatalogPage<Content: UIViewCatalogPresentable>: View {
-
-  let schemes: [ColorScheme]
-
-  var body: some View {
-    NavigationView {
-      ScrollView(.vertical, showsIndicators: true) {
-        ForEach(values: Content.previewModels) { model in
-          ForEach(values: schemes) { scheme in
-            item(title: "\(scheme):  \(model)") {
-              ColorSchemePreview(scheme: scheme) {
-                Content.preview(with: model)
-              }
-            }
-          }
-        }
-      }.navigationBarTitle(String(describing: Content.self))
-    }
-  }
-
-  func item<Content: View>(title: String,
-                           @ViewBuilder content: @escaping () -> Content
-  ) -> some View {
-    VStack(alignment: .center, spacing: 12.0) {
-      Text(title)
-        .font(.subheadline)
-        .fontWeight(.bold)
-      content()
-    }
-    .frame(maxWidth: .infinity, alignment: .center)
-    .padding()
-  }
-}
-
-//@available(iOS 13, *)
-//struct CatalogPage_Previews: PreviewProvider {
-//  static var previews: some View {
-//    CatalogPage<UISwitch>(schemes: [.light, .dark, ])
-//    CatalogPage<UILabel>(schemes: [.light, .dark, ])
-//  }
-//}

Sources/UIPreview/ComponentPreview.swift

@@ -26,7 +26,8 @@ struct ComponentPreview<Component: View>: View {
     ForEach(values: ColorScheme.allCases) { scheme in
       ForEach(values: ContentSizeCategory.smallestAndLargest) { category in
         self.component
-          .previewLayout(.sizeThatFits).padding()
+          .previewLayout(.sizeThatFits)
+          .padding()
           .background(Color(.systemBackground))
           .colorScheme(scheme)
           .environment(\.sizeCategory, category)

Sources/UIPreview/Preview.swift

@@ -10,11 +10,14 @@ extension UICatalog {
       self.view = view
     }
 
-    public func asViewController() -> UIViewController {
+    func preview() -> some View {
       ScrollView(.vertical, showsIndicators: true) {
         view
       }.navigationBarTitle(title)
-      .asViewController()
+    }
+
+    public func asViewController() -> UIViewController {
+      preview().asViewController()
     }
 
     let title: String

Sources/UIPreview/PreviewConfiguration.swift

@@ -26,3 +26,8 @@ extension UICatalog.Theme {
     }
   }
 }
+
+@available(iOS 13, *)
+extension UICatalog.PreviewConfiguration {
+  var colorSchemes: [ColorScheme] { themes.map(\.scheme) }
+}

Sources/UIPreview/PreviewDescriptor.swift

@@ -6,10 +6,10 @@ import UIKit
 extension UICatalog {
 
   public struct PreviewDescriptor: Identifiable, Hashable {
-    let view: AnyView
+    let builder: () -> AnyView
     public let id: String
     public let title: String
-    public var preview: Preview { Preview(view, title: title) }
+    public var preview: Preview { Preview(builder(), title: title) }
 
     public func hash(into hasher: inout Hasher) {
       hasher.combine(id)
@@ -19,7 +19,7 @@ extension UICatalog {
       lhs.id == rhs.id
     }
   }
-  
+
 }
 
 public extension UICatalog.PreviewDescriptor {
@@ -28,8 +28,6 @@ public extension UICatalog.PreviewDescriptor {
                 title: String? = nil) where Content: UIViewCatalogPresentable {
     id = "\(content)"
     self.title = title ?? "\(content)"
-    //    self.view = CatalogPage<Content>(schemes: themes.map(\.scheme))
-
-    self.view = AnyView(Text("sdf"))
+    self.builder = { AnyView(CatalogItem<Content>(configuration: configuration)) }
   }
 }