Adds inspector view modifier

Sources/SwiftUINavigation/Inspector.swift

@@ -0,0 +1,75 @@
+#if canImport(SwiftUI)
+  import Foundation
+  import SwiftUI
+
+  @available(iOS 17, macOS 14, *)
+  @available(tvOS, unavailable)
+  @available(watchOS, unavailable)
+  @available(visionOS, unavailable)
+  extension View {
+    /// Shows an inspector using a binding as a data source for the inspector's content.
+    ///
+    /// SwiftUI comes with a `inspector(isPresented:)` view modifier that is powered by a binding to
+    /// a Boolean.
+    ///
+    /// This overload differs in that it passes a _binding_ to the unwrapped value, instead. This
+    /// gives the inspector the ability to write changes back to its source of truth.
+    ///
+    /// ```swift
+    /// struct TimelineView: View {
+    ///   @State var draft: Post?
+    ///
+    ///   var body: Body {
+    ///     Button("Compose") {
+    ///       self.draft = Post()
+    ///     }
+    ///     .inspector(item: $draft) { $draft in
+    ///       ComposeView(post: $draft, onSubmit: { ... })
+    ///     }
+    ///   }
+    /// }
+    ///
+    /// struct ComposeView: View {
+    ///   @Binding var post: Post
+    ///   var body: some View { ... }
+    /// }
+    /// ```
+    ///
+    /// - Parameters:
+    ///   - item: A binding to an optional source of truth for the inspector. When `item` is
+    ///     non-`nil`, the system passes the item's content to the modifier's closure. You display
+    ///     this content in an inspector that you create that the system displays to the user.
+    ///   - content: A closure returning the content of the inspector.
+    @_disfavoredOverload
+    public func inspector<Item, Content: View>(
+      item: Binding<Item?>,
+      @ViewBuilder content: @escaping (Binding<Item>) -> Content
+    ) -> some View {
+      inspector(isPresented: Binding(item)) {
+        if let defaultValue = item.wrappedValue {
+          content(Binding(unwrapping: item, default: defaultValue))
+        }
+      }
+    }
+
+    /// Presents a sheet using a binding as a data source for the sheet's content.
+    ///
+    /// A version of ``SwiftUI/View/inspector(item:content:)`` that is passed an item
+    /// and not a binding to an item.
+    ///
+    /// - Parameters:
+    ///   - item: A binding to an optional source of truth for the inspector. When `item` is
+    ///     non-`nil`, the system passes the item's content to the modifier's closure. You display
+    ///     this content in an inspector  that you create that the system displays to the user.
+    ///   - content: A closure returning the content of the inspector.
+    @_disfavoredOverload
+    public func inspector<Item, Content: View>(
+      item: Binding<Item?>,
+      @ViewBuilder content: @escaping (Item) -> Content
+    ) -> some View {
+      inspector(item: item) {
+        content($0.wrappedValue)
+      }
+    }
+  }
+#endif