🌲 Update

Development/Demo/MyBook.swift

@@ -19,12 +19,57 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-
 import Foundation
-
 import StorybookKit
 import SwiftUISupport
 
+@MainActor
+let myBook2 = BookContainer(
+  store: .init(
+    title: "MyUI",
+    links: {
+
+      BookNavigationLink(title: "Preview UI") {
+        BookSection(title: "Section") {
+
+          Text(
+            """
+            Something description about this section.
+            """
+          )
+
+          BookPreview { _ in
+            let view = UIView(frame: .init(x: 0, y: 0, width: 80, height: 80))
+            view.backgroundColor = .systemPurple
+            NSLayoutConstraint.activate([
+              view.widthAnchor.constraint(equalToConstant: 80),
+              view.heightAnchor.constraint(equalToConstant: 80),
+            ])
+            return view
+          }
+
+          BookPreview(title: "A component") { _ in
+            let view = UIView(frame: .null)
+            view.backgroundColor = .systemPurple
+            return view
+          }
+          .previewFrame(width: 80, height: 80)
+
+          BookPreview { _ in
+            let view = UIView(frame: .init(x: 0, y: 0, width: 80, height: 80))
+            view.backgroundColor = .systemPurple
+            return view
+          }
+          .previewFrame(maxWidth: .greatestFiniteMagnitude, idealHeight: 10)
+
+        }
+
+      }
+
+    }
+  )
+)
+
 let myBook: some BookType = Book(title: "MyUI") {
 
   Text("MyBook")
@@ -36,27 +81,34 @@ let myBook: some BookType = Book(title: "MyUI") {
     BookNavigationLink(title: "Preview UI") {
       BookPage(title: "Typography") {
 
-        Text("""
-Here is `BookHeadline`, It allows us to describe something big picture.
-""")
-
-        Text("""
-Here is `BookParagpraph`
-It allows us to display multiple lines.
+        Text(
+          """
+          Here is `BookHeadline`, It allows us to describe something big picture.
+          """
+        )
 
-Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,
-""")
+        Text(
+          """
+          Here is `BookParagpraph`
+          It allows us to display multiple lines.
 
-        Text("""
-Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,
-""")
+          Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,
+          """
+        )
 
+        Text(
+          """
+          Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,
+          """
+        )
 
         BookSection(title: "Section") {
 
-          Text("""
-Something description about this section.
-""")
+          Text(
+            """
+            Something description about this section.
+            """
+          )
 
           BookPreview { _ in
             let view = UIView(frame: .init(x: 0, y: 0, width: 80, height: 80))
@@ -81,7 +133,7 @@ Something description about this section.
             return view
           }
           .previewFrame(maxWidth: .greatestFiniteMagnitude, idealHeight: 10)
-          
+
         }
 
         BookSection(title: "Section") {
@@ -167,10 +219,10 @@ Something description about this section.
     }
 
   }
-  
+
 }
 
-fileprivate func labelExpandingTestBook() -> some View {
+private func labelExpandingTestBook() -> some View {
 
   BookSection(title: "UILabel updating text") {
     BookPreview { context in

Development/Demo/RootView.swift

@@ -29,10 +29,12 @@ struct RootView: View {
   var body: some View {
     VStack {
 
-      StorybookDisplayRootView(
-        book: myBook
-      )
+//      StorybookDisplayRootView(
+//        book: myBook
+//      )
 
+      StorybookDisplayRootView2(book: myBook2)
+
     }
   }
 }

Development/Storybook.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -18,6 +18,15 @@
         "version" : "0.10.0"
       }
     },
+    {
+      "identity" : "resultbuilderkit",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/FluidGroup/ResultBuilderKit",
+      "state" : {
+        "revision" : "34aa57fcee5ec3ee0f368b05cb53c7919c188ab2",
+        "version" : "1.3.0"
+      }
+    },
     {
       "identity" : "swiftui-gesture-velocity",
       "kind" : "remoteSourceControl",

Package.swift

@@ -15,12 +15,14 @@ let package = Package(
     .package(url: "https://github.com/FluidGroup/TextureBridging.git", branch: "main"),
     .package(url: "https://github.com/FluidGroup/TextureSwiftSupport.git", branch: "main"),
     .package(url: "https://github.com/FluidGroup/swiftui-support", from: "0.4.1"),
+    .package(url: "https://github.com/FluidGroup/ResultBuilderKit", from: "1.3.0")
   ],
   targets: [
     .target(
       name: "StorybookKit",
       dependencies: [
-        .product(name: "SwiftUISupport", package: "swiftui-support")
+        .product(name: "SwiftUISupport", package: "swiftui-support"),
+        "ResultBuilderKit"
       ]
     ),
     .target(

Sources/StorybookKit/Primitives/Book.swift

@@ -19,6 +19,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+import ResultBuilderKit
 import SwiftUI
 
 public protocol BookType: View {
@@ -45,23 +46,114 @@ public struct Book<Content: View>: BookType {
       }
     }
     .navigationTitle(title)
-    .environment(\.bookContext, BookContext())
 
   }
 
 }
 
+public final class BookStore: ObservableObject {
+
+  @Published var historyLinks: [BookNavigationLink] = []
+
+  public let title: String
+  public let links: [BookNavigationLink]
+
+  private let userDefaults = UserDefaults(suiteName: "jp.eure.storybook2") ?? .standard
+
+  public init(
+    title: String,
+    @ArrayBuilder<BookNavigationLink> links: () -> [BookNavigationLink]
+  ) {
+    self.title = title
+    self.links = links().sorted(by: { $0.title < $1.title })
+
+    updateHistory()
+  }
+
+  private func updateHistory() {
+
+    let indexes = userDefaults.array(forKey: "history") as? [Int] ?? []
+
+    let _links = indexes.compactMap { index -> BookNavigationLink? in
+      guard let link = links.first(where: { $0.declarationIdentifier.index == index }) else {
+        return nil
+      }
+      return link
+    }
+
+    historyLinks = _links
+
+  }
+
+  func onOpen(link: BookNavigationLink) {
+
+    let index = link.declarationIdentifier.index
+
+    var current = userDefaults.array(forKey: "history") as? [Int] ?? []
+    if let index = current.firstIndex(of: index) {
+      current.remove(at: index)
+    }
+    current.insert(index, at: 0)
+    current = Array(current.prefix(5))
+
+    userDefaults.set(current, forKey: "history")
+
+    updateHistory()
+  }
+
+}
+
+public struct BookContainer: BookType {
+
+  @ObservedObject var store: BookStore
+
+  @MainActor
+  public init(
+    store: BookStore
+  ) {
+    self.store = store
+  }
+
+  public var body: some View {
+    NavigationView {
+      List {
+        Section {
+          ForEach(store.historyLinks) { link in
+            link
+          }
+        } header: {
+          Text("History")
+        }
+        Section {
+          ForEach(store.links) { link in
+            link
+          }
+        } header: {
+          Text("Contents")
+        }
+      }
+      .listStyle(.grouped)
+    }
+    .navigationTitle(store.title)
+    .environment(\.bookContext, store)
+  }
+
+}
+
 public final class BookContext {
 
+  func onOpen(link: BookNavigationLink) {
+    print(link)
+  }
 }
 
 private enum BookContextKey: EnvironmentKey {
-  static var defaultValue: BookContext?
+  static var defaultValue: BookStore?
 }
 
 extension EnvironmentValues {
 
-  public var bookContext: BookContext? {
+  public var bookContext: BookStore? {
     get {
       self[BookContextKey.self]
     }

Sources/StorybookKit/Primitives/BookNavigationLink.swift

@@ -43,18 +43,24 @@ private func issueUniqueNumber() -> Int {
 }
 
 /// A component that displays a disclosure view.
-public struct BookNavigationLink<Destination: View>: BookView {
+public struct BookNavigationLink: BookView, Identifiable {
+
+  @Environment(\.bookContext) var context
+
+  public var id: DeclarationIdentifier {
+    declarationIdentifier
+  }
 
   public let title: String
-  public let destination: Destination
+  public let destination: AnyView
   public let declarationIdentifier: DeclarationIdentifier
 
-  public init(
+  public init<Destination: View>(
     title: String,
     @ViewBuilder destination: () -> Destination
   ) {
     self.title = title
-    self.destination = destination()
+    self.destination = AnyView(destination())
     self.declarationIdentifier = .init()
   }
 
@@ -64,12 +70,14 @@ public struct BookNavigationLink<Destination: View>: BookView {
       title,
       destination: {
         GeometryReader(content: { geometry in
-
           ScrollView {
             destination
               .frame(width: geometry.size.width)
           }
         })
+        .onAppear(perform: {
+          context?.onOpen(link: self)
+        })
       }
     )
 

Sources/StorybookKit/StorybookDisplayRootView.swift

@@ -20,6 +20,25 @@ public struct StorybookDisplayRootView<Book: BookType>: View {
   }
 }
 
+public struct StorybookDisplayRootView2: View {
+
+  public let book: BookContainer
+
+  public init(book: BookContainer) {
+    self.book = book
+  }
+
+  public var body: some View {
+
+    _ViewControllerHost {
+      let controller = _ViewController(book: book)
+      return controller
+    }
+
+  }
+}
+
+
 final class _ViewController<Book: BookType>: UIViewController {
 
   private let book: Book