Merge branch 'feature/contentview-vb-1' into develop

README.md

@@ -23,16 +23,13 @@ More details will be posted but to get started.
 
   class HomePage: ViewController {
 
-    struct ContentView: View {
-
-      var body: some View {
-        VStack {
-          Text("Welcome to MWC!")
-            .font(.title)
-            .padding()
-
-          Spacer()
-        }
+    var view: some View {
+      VStack {
+        Text("Welcome to MWC!")
+          .font(.title)
+          .padding()
+
+        Spacer()
       }
     }
   }
@@ -58,16 +55,13 @@ More details will be posted but to get started.
 
   class Settings: ViewController {
 
-    struct ContentView: View {
-
-      var body: some View {
-        VStack {
-          Text("Welcome to Settings!")
-            .font(.title)
-            .padding()
-
-          Spacer()
-        }
+    var view: some View { // the View being controlled
+      VStack {
+        Text("Welcome to Settings!")
+          .font(.title)
+          .padding()
+
+        Spacer()
       }
     }
   }
@@ -82,24 +76,19 @@ More details will be posted but to get started.
       show(Settings()) // or `present(Settings())`
     }
 
-    struct ContentView: View {
-
-      @EnvironmentObject private var viewController : HomePage
-
-      var body: some View {
-        VStack {
-          Text("Welcome to MWC!")
-            .font(.title)
-            .padding()
-
-          Divider()
-
-          Button(action: viewController.configureApp) {
-            Label("Configure", systemImage: "gear")
-          }
+    var view: some View {
+      VStack {
+        Text("Welcome to MWC!")
+          .font(.title)
+          .padding()
 
-          Spacer()
+        Divider()
+
+        Button(action: self.configureApp) {
+          Label("Configure", systemImage: "gear")
         }
+
+        Spacer()
       }
     }
   }
@@ -144,20 +133,17 @@ inline a `NavigationLink`, use `PushLink`, which wraps that.
 
   class HomePage: ViewController {
 
-    struct ContentView: View {
-
-      var body: some View {
-        VStack {
-          Text("Welcome to MWC!")
-            .font(.title)
-            .padding()
-
-          Divider()
+    var view: some View {
+      VStack {
+        Text("Welcome to MWC!")
+          .font(.title)
+          .padding()
 
-          PushLink("Open Settings", to: Settings())
-
-          Spacer()
-        }
+        Divider()
+
+        PushLink("Open Settings", to: Settings())
+
+        Spacer()
       }
     }
   }

Sources/ViewController/AnyViewController.swift

@@ -34,17 +34,20 @@ import SwiftUI
  */
 public final class AnyViewController: ViewController {
 
-  public  var id : ObjectIdentifier { ObjectIdentifier(viewController) }
+  public   var id : ObjectIdentifier { ObjectIdentifier(viewController) }
 
-  public  let viewController : _ViewController
-  private var subscription   : AnyCancellable?
+  public   let viewController : _ViewController
+  private  var subscription   : AnyCancellable?
 
   @usableFromInline
-  init<VC>(_ viewController: VC) where VC: ViewController {
+  internal let contentView    : () -> AnyView
+
+  public init<VC>(_ viewController: VC) where VC: ViewController {
     assert(!(viewController is AnyViewController),
            "Attempt to nest an AnyVC into another \(viewController)")
 
     self.viewController = viewController
+    self.contentView    = { AnyView(viewController.view) }
 
     subscription = viewController.objectWillChange.sink { [weak self] _ in
       self?.objectWillChange.send()
@@ -54,9 +57,9 @@ public final class AnyViewController: ViewController {
   /**
    * An initializer that avoids nesting `AnyViewController`s into themselves.
    */
-  @usableFromInline
   init(_ viewController: AnyViewController) {
     self.viewController = viewController.viewController
+    self.contentView    = viewController.contentView
 
     // TBD: Can't unwrap this?
     subscription = viewController.objectWillChange.sink {
@@ -70,9 +73,8 @@ public final class AnyViewController: ViewController {
   // Those are typed erased by the base protocol already (_ViewController).
 
   @inlinable
-  public var contentView           : AnyView { anyContentView }
-  @inlinable
-  public var anyContentView        : AnyView { viewController.anyContentView }
+  @ViewBuilder public var view : AnyView { contentView() }
+
   @inlinable
   public var controlledContentView : AnyView { anyControlledContentView }
   @inlinable

Sources/ViewController/ContainerViewControllers/NavigationController.swift

@@ -145,7 +145,7 @@ open class NavigationController<RootVC>: ViewController, _NavigationController
 
   private func markAsPresentingViewController() {
     rootViewController.presentingViewController = self
-    activePresentations.append(TypedViewControllerPresentation(
+    activePresentations.append(ViewControllerPresentation(
       viewController: _rootViewController,
       mode: .custom // not .navigation, that would activate the bg link!
     ))
@@ -161,18 +161,11 @@ open class NavigationController<RootVC>: ViewController, _NavigationController
 
   // MARK: - View
 
-  public struct ContentView: View {
-
-    @EnvironmentObject private var viewController : NavigationController
-
-    public init() {}
-
-    public var body: some View {
-      NavigationView {
-        viewController._rootViewController.contentView
-          .controlled(by: viewController._rootViewController)
-          .navigationTitle(viewController._rootViewController.navigationTitle)
-      }
+  public var view: some View  {
+    NavigationView {
+      _rootViewController.view
+        .controlled(by: _rootViewController)
+        .navigationTitle(_rootViewController.navigationTitle)
     }
   }
 }

Sources/ViewController/MainViewController.swift

@@ -13,8 +13,6 @@ import SwiftUI
  * i.e. one which starts a new VC hierarchy.
  * Usually only one root VC is used per scene.
  *
- * Checkout the ``View/main`` modifier for the more general solution.
- *
  * E.g. this could be used in the `ContentView` of an app like this:
  * ```swift
  * struct ContentView: View {
@@ -47,7 +45,7 @@ public struct MainViewController<VC>: View where VC: ViewController {
   }
 
   public var body: some View {
-    VC.ContentView()
-      .controlled(by: viewController)
+    viewController
+      .controlledContentView
   }
 }

Sources/ViewController/NavigationLink/PushLink.swift

@@ -19,17 +19,17 @@ import SwiftUI
  *
  * Content View Example:
  * ```swift
- * struct ContentView: View {
- *   var body: some View {
+ * class HomePage: ViewController {
+ *   var view: some View {
  *     PushLink("Preferences…", to: PreferencesPage())
  *   }
  * }
  * ```
  *
  * Explicit View Example:
  * ```swift
- * struct ContentView: View {
- *   var body: some View {
+ * class HomePage: ViewController {
+ *   var view: some View {
  *     PushLink(to: PreferencesPage(), using: Text("Prefs!") {
  *       Text("Preferences…")
  *     }
@@ -200,7 +200,7 @@ public struct PushLink<VC, CV, Label>: View
 extension PushLink {
 
   /**
-   * Create a ``PushLink`` that is using the ``ViewController/ContentView``
+   * Create a ``PushLink`` that is using the ``ViewController/view``
    * as the destination.
    *
    * Example:
@@ -221,7 +221,7 @@ extension PushLink {
   }
 
   /**
-   * Create a ``PushLink`` that is using the ``ViewController/ContentView``
+   * Create a ``PushLink`` that is using the ``ViewController/view``
    * as the destination.
    *
    * Example:

Sources/ViewController/Presentations/AutoPresentation.swift

@@ -18,6 +18,28 @@ import SwiftUI
 struct AutoPresentationViewModifier<VC>: ViewModifier where VC: ViewController {
 
   @ObservedObject var viewController : VC
+
+  fileprivate struct Present: View {
+
+    @ObservedObject var presentingViewController : VC
+    let mode : ViewControllerPresentationMode
+
+    var body: some View {
+      if let presentation =
+          presentingViewController.activePresentation(for: mode)
+      {
+        let presentedViewController = presentation.viewController
+        presentedViewController.anyControlledContentView
+          .environment(\.viewControllerPresentationMode, mode)
+          .navigationTitle(presentedViewController.navigationTitle)
+      }
+      else {
+        TypeMismatchInfoView<AnyViewController, VC>(
+          parent: presentingViewController, expectedMode: mode
+        )
+      }
+    }
+  }
 
   func body(content: Content) -> some View {
     // Note: Also used internally during presentation.
@@ -27,34 +49,14 @@ struct AutoPresentationViewModifier<VC>: ViewModifier where VC: ViewController {
       .sheet(
         isPresented: viewController.isPresentingMode(.sheet),
         content: {
-          if let presentation = viewController.activePresentation(for: .sheet) {
-            presentation.contentView()
-              .environment(\.viewControllerPresentationMode, .sheet)
-              .navigationTitle(presentation.viewController.navigationTitle)
-          }
-          else {
-            TypeMismatchInfoView<AnyViewController, VC>(
-              parent: viewController, expectedMode: .sheet
-            )
-          }
+          Present(presentingViewController: viewController, mode: .sheet)
         }
       )
       .background(
         NavigationLink(
           isActive: viewController.isPresentingMode(.navigation),
           destination: {
-            if let presentation = viewController
-                      .activePresentation(for: .navigation)
-            {
-              presentation.contentView()
-                .environment(\.viewControllerPresentationMode, .navigation)
-                .navigationTitle(presentation.viewController.navigationTitle)
-            }
-            else {
-              TypeMismatchInfoView<AnyViewController, VC>(
-                parent: viewController, expectedMode: .navigation
-              )
-            }
+            Present(presentingViewController: viewController, mode: .navigation)
           },
           label: { Color.clear } // TBD: EmptyView?
         )

Sources/ViewController/Presentations/Presentation.swift

@@ -102,7 +102,15 @@ public extension _ViewController {
         // helpers.
         guard !isShowing else {
           // isShowing=true would be activation
-          logger.warning("Attempt to activate VC via Binding, won't work!")
+          if self.activePresentations.contains(where: { $0.mode == mode }) {
+            logger.debug(
+              "Attempt to activate VC via Binding, mode already active!")
+          }
+          else {
+            // FIXME: This can sometimes be seen in sheets, figure out why
+            logger.warning(
+              "Attempt to activate VC via Binding, won't work \(self)!")
+          }
           return
         }
 
@@ -279,7 +287,7 @@ public extension _ViewController {
       activePresentation.viewController.dismiss()
     }
 
-    activePresentations.append(TypedViewControllerPresentation<VC>(
+    activePresentations.append(ViewControllerPresentation(
       viewController: viewController,
       mode: mode
     ))

Sources/ViewController/Presentations/PresentationMode.swift

@@ -14,6 +14,15 @@ import SwiftUI
  * ```swift
  * public struct ContentView: View {
  *   @Environment(\.viewControllerPresentationMode) private var mode
+ *
+ *   var body: some View {
+ *     if mode == .sheet {
+ *       Text("I'm in a sheet!")
+ *     }
+ *     else {
+ *       Text("I'm in a sheet, NOT!")
+ *     }
+ *   }
  * }
  * ```
  */