Use variadic view (#56)

EmergeTools · Oct 16, 2023 · 3b71edd · 3b71edd
1 parent 8ff68eb
commit 3b71edd
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Showing 8 changed files with 27 additions and 199 deletions.
diff --git a/Sources/PreviewGallery/ModuleScreens.swift b/Sources/PreviewGallery/ModuleScreens.swift
@@ -25,12 +25,12 @@ struct ModuleScreens: View {
         let featurePreviews = provider.previews.filter { $0.requiresFullScreen }
         NavigationLink {
           if featurePreviews.count == 1 {
-            try! featurePreviews[0].view()
+            featurePreviews[0].view()
           } else {
             List {
               ForEach(featurePreviews) { preview in
                 NavigationLink(preview.displayName ?? provider.displayName) {
-                  try! preview.view()
+                  preview.view()
                 }
               }
             }.navigationTitle(provider.displayName)

diff --git a/Sources/PreviewGallery/PreviewCell.swift b/Sources/PreviewGallery/PreviewCell.swift
@@ -16,7 +16,7 @@ struct PreviewCell: View {
   var body: some View {
     PreferredColorSchemeWrapper {
       VStack {
-        try! preview.view()
+        preview.view()
           .padding(.vertical, 8)
           .border(Color.dynamicBackground)
           .background {

diff --git a/Sources/SnapshotPreviewsCore/ExpandingViewController.swift b/Sources/SnapshotPreviewsCore/ExpandingViewController.swift
@@ -46,14 +46,12 @@ public final class ExpandingViewController<Content: View>: UIHostingController<A
 
   private var didCall = false
   private var previousHeight: CGFloat?
-  private let supportsExpansion: Bool
 
   private var heightAnchor: NSLayoutConstraint?
 
   var expansionSettled: ((EmergeRenderingMode?, Float?) -> Void)?
 
-  init(rootView: Content, layout: PreviewLayout, supportsExpansion: Bool) {
-    self.supportsExpansion = supportsExpansion
+  init(rootView: Content, layout: PreviewLayout) {
     let newView = finder?(rootView)
     super.init(rootView: newView != nil ? AnyView(newView!) : AnyView(rootView))
 
@@ -94,9 +92,7 @@ public final class ExpandingViewController<Content: View>: UIHostingController<A
       return
     }
 
-    let expansionPreference = stateMirror?.descendant("expansionPreference") as? Bool
-
-    let supportsExpansion = expansionPreference ?? self.supportsExpansion
+    let supportsExpansion = stateMirror?.descendant("expansionPreference") as? Bool ?? true
     let scrollView = view.firstScrollView
     if let scrollView, supportsExpansion {
       let diff = Int(scrollView.contentSize.height - scrollView.visibleContentHeight)

diff --git a/Sources/SnapshotPreviewsCore/PreviewProviderExtraction.swift b/Sources/SnapshotPreviewsCore/PreviewProviderExtraction.swift
diff --git a/Sources/SnapshotPreviewsCore/SnapshotPreviewsCore.swift b/Sources/SnapshotPreviewsCore/SnapshotPreviewsCore.swift
@@ -7,21 +7,14 @@ extension View {
 }
 
 public struct Preview: Identifiable {
-  init<P>(preview: SwiftUI._Preview, extraction: PreviewProviderExtraction<P>) {
+  init<P: SwiftUI.PreviewProvider>(preview: _Preview, type: P.Type) {
     previewId = "\(preview.id)"
     orientation = preview.interfaceOrientation
     displayName = preview.displayName
     device = preview.device
     layout = preview.layout
     _view = {
-      let children = try extraction.previews.get()
-
-      let (v, modifiers) = children[preview.id]
-      var result = v
-      for mod in modifiers {
-        result = result.applyModifier(mod)
-      }
-      return AnyView(result)
+      AnyView(P.previews.selectSubview(preview.id))
     }
   }
 
@@ -43,7 +36,7 @@ public struct Preview: Identifiable {
     displayName = preview.descendant("displayName") as? String
     let source = Mirror(reflecting: preview.descendant("source")!)
     let sourceType = source.subjectType
-    let _view: @MainActor () throws -> AnyView
+    let _view: @MainActor () -> AnyView
     if (String(describing: sourceType) == "ViewPreviewSource") {
       _view = {
         let makeView = source.descendant("makeView") as! @MainActor () -> any SwiftUI.View
@@ -63,9 +56,9 @@ public struct Preview: Identifiable {
   public let displayName: String?
   public let device: PreviewDevice?
   public let layout: PreviewLayout
-  private let _view: @MainActor () throws -> AnyView
-  @MainActor public func view() throws -> AnyView {
-    try _view()
+  private let _view: @MainActor () -> AnyView
+  @MainActor public func view() -> AnyView {
+    _view()
   }
 }
 
@@ -74,8 +67,7 @@ public struct PreviewType: Hashable, Identifiable {
   init<A: PreviewProvider>(typeName: String, preivewProvider: A.Type) {
     self.typeName = typeName
     self.fileID = nil
-    let extraction = PreviewProviderExtraction<A>()
-    self.previews = A._allPreviews.map { Preview(preview: $0, extraction: extraction) }
+    self.previews = A._allPreviews.map { Preview(preview: $0, type: A.self) }
     self.platform = A.platform
   }
 

diff --git a/Sources/SnapshotPreviewsCore/View+Snapshot.swift b/Sources/SnapshotPreviewsCore/View+Snapshot.swift
@@ -17,16 +17,14 @@ extension View {
   public func snapshot(
     layout: PreviewLayout,
     window: UIWindow,
-    legacySupportsExpansion: Bool,
-    legacyRenderingMode: EmergeRenderingMode?,
     async: Bool,
     completion: @escaping (Result<UIImage, Error>, Float?) -> Void)
   {
     UIView.setAnimationsEnabled(false)
     let animationDisabledView = self.transaction { transaction in
       transaction.disablesAnimations = true
     }
-    let controller = ExpandingViewController(rootView: animationDisabledView, layout: layout, supportsExpansion: legacySupportsExpansion)
+    let controller = ExpandingViewController(rootView: animationDisabledView, layout: layout)
     if #available(iOS 16, *) {
       controller.sizingOptions = .intrinsicContentSize
     }
@@ -40,11 +38,11 @@ extension View {
     controller.expansionSettled = { renderingMode, precision in
       if async {
         DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
-          completion(Self.takeSnapshot(layout: layout, renderingMode: legacyRenderingMode ?? renderingMode, rootVC: containerVC, controller: controller), precision)
+          completion(Self.takeSnapshot(layout: layout, renderingMode: renderingMode, rootVC: containerVC, controller: controller), precision)
         }
       } else {
         DispatchQueue.main.async {
-          completion(Self.takeSnapshot(layout: layout, renderingMode: legacyRenderingMode ?? renderingMode, rootVC: containerVC, controller: controller), precision)
+          completion(Self.takeSnapshot(layout: layout, renderingMode: renderingMode, rootVC: containerVC, controller: controller), precision)
         }
       }
     }

diff --git a/Sources/SnapshotPreviewsCore/ViewInspection.swift b/Sources/SnapshotPreviewsCore/ViewInspection.swift
@@ -7,154 +7,21 @@
 
 import SwiftUI
 
-public enum ViewInspection {
-
-   static func attribute(label: String, value: Any) -> Any? {
-      let mirror = (value as? Mirror) ?? Mirror(reflecting: value)
-      return mirror.descendant(label)
-   }
-
-   static func tupleChildren(_ content: Any) -> [any View] {
-      let tupleViews = Self.attribute(label: "value", value: content)!
-      let childrenCount = Mirror(reflecting: tupleViews).children.count
-      return (0..<childrenCount).map { Self.attribute(label: ".\($0)", value: tupleViews) as! any View }
-   }
-
-  public static func childrenIfMultiple(of view: some View) -> [(any View, [any ViewModifier])] {
-    let children = children(of: view)
-    if children.count == 1 {
-      return [(view, [])]
-    }
-    return children
-  }
-
-  private static func children(of view: some View) -> [(any View, [any ViewModifier])] {
-    let viewType = type(of: view)
-    let typeName = String(reflecting: viewType)
-    if typeName.starts(with: "Swift.Optional<") {
-      if let child = Mirror(reflecting: view).children.first?.value as? any View {
-        return children(of: child)
-      }
-    } else if typeName.starts(with: "SwiftUI._ConditionalContent") {
-      let storage = Self.attribute(label: "storage", value: view)!
-      if let trueContent = Self.attribute(label: "trueContent", value: storage) as? any View {
-        return childrenIfMultiple(of: trueContent)
-      } else {
-        let content = Self.attribute(label: "falseContent", value: storage) as! any View
-        return childrenIfMultiple(of: content)
-      }
-    } else if typeName.starts(with: "SwiftUI.EmptyView") {
-      return []
-    } else if typeName.starts(with: "SwiftUI.Tuple") {
-      return tupleChildren(view).flatMap { childrenIfMultiple(of: $0) }
-    } else if typeName.starts(with: "SwiftUI.Group") {
-      let content = Self.attribute(label: "content", value: view) as! any View
-      return childrenIfMultiple(of: content)
-    } else if typeName.starts(with: "SwiftUI.ForEach"), let provider = view as? ViewsProvider {
-      return provider.views().flatMap { childrenIfMultiple(of: $0) }
-    } else if typeName.starts(with: "SwiftUI.AnyView") {
-      let storage = Self.attribute(label: "storage", value: view)!
-      let storageView = Self.attribute(label: "view", value: storage) as! any View
-      return childrenIfMultiple(of: storageView)
-    } else if typeName.starts(with: "SwiftUI.ModifiedContent") {
-      let content = Self.attribute(label: "content", value: view) as! any View
-      let modifier = Self.attribute(label: "modifier", value: view) as! any ViewModifier
-      return childrenIfMultiple(of: content).map { (view, modifiers) in
-        var modifiers = modifiers
-        modifiers.append(modifier)
-        return (view, modifiers)
-      }
-    }
-    if viewType.Body != Never.self && !typeName.starts(with: "SwiftUI.") {
-      return childrenIfMultiple(of: view.body)
-    }
-    return [(view, [])]
-  }
-
-  private static func getModifier<T>(of view: some View, parseModifier: (Any) -> T?) -> T? {
-    let viewType = type(of: view)
-    let typeName = String(reflecting: viewType)
-    if typeName.starts(with: "SwiftUI.ModifiedContent") {
-      let modifier = Self.attribute(label: "modifier", value: view)!
-      if let result = parseModifier(modifier) {
-        return result
-      }
-      let content = Self.attribute(label: "content", value: view) as! any View
-      return getModifier(of: content, parseModifier: parseModifier)
-    } else if typeName.starts(with: "SwiftUI.AnyView") {
-      let storage = Self.attribute(label: "storage", value: view)!
-      let storageView = Self.attribute(label: "view", value: storage) as! any View
-      return getModifier(of: storageView, parseModifier: parseModifier)
-    } else if typeName.starts(with: "SwiftUI.Tuple") {
-      return getModifier(of: tupleChildren(view)[0], parseModifier: parseModifier)
-    } else if typeName.starts(with: "SwiftUI.Group") {
-      let content = Self.attribute(label: "content", value: view) as! any View
-      return getModifier(of: content, parseModifier: parseModifier)
-    } else if typeName.starts(with: "SwiftUI.ForEach"), let provider = view as? ViewsProvider {
-      return getModifier(of: provider.views()[0], parseModifier: parseModifier)
-    }
-    if viewType.Body != Never.self && !typeName.starts(with: "SwiftUI.") {
-      return getModifier(of: view.body, parseModifier: parseModifier)
-    }
-    return nil
-  }
-
-  public static func precision(of view: some View) -> Float? {
-    return getModifier(of: view) { modifier in
-      let typeName = String(reflecting: modifier)
-      if typeName.contains(".EmergePrecisionModifier") {
-        if let precision = Self.attribute(label: "precision", value: modifier) as? Float {
-          return precision
+fileprivate struct ViewSelector: _VariadicView_MultiViewRoot {
+  let position: Int
+    func body(children: _VariadicView.Children) -> some View {
+      ForEach(Array(children.enumerated()), id: \.0) { count, item in
+        if count == position {
+          item
         }
       }
-      return nil
     }
-  }
-
-  public static func shouldExpand(_ view: some View) -> Bool {
-    return getModifier(of: view) { modifier in
-      let typeName = String(reflecting: modifier)
-      if typeName.contains(".EmergeExpansionModifier") {
-        if let enabled = Self.attribute(label: "enabled", value: modifier) as? Bool {
-          return enabled
-        }
-      }
-      return true
-    } ?? true
-  }
+}
 
-  public static func renderingMode(of view: some View) -> EmergeRenderingMode? {
-    return getModifier(of: view) { modifier in
-      let typeName = String(reflecting: modifier)
-      if typeName.contains(".RenderingModeModifier") {
-        if let mode = Self.attribute(label: "renderingMode", value: modifier) {
-          let caseName = String(reflecting: mode)
-          if caseName.contains("EmergeRenderingMode.coreAnimation") {
-            return .coreAnimation
-          } else if caseName.contains("EmergeRenderingMode.uiView") {
-            return .uiView
-          }
-        }
-      }
-      return nil
+extension View {
+  func selectSubview(_ position: Int) -> some View {
+    _VariadicView.Tree(ViewSelector(position: position)) {
+      self
     }
   }
 }
-
-protocol ViewsProvider {
-   func views() -> [any View]
-}
-
-extension ForEach: ViewsProvider where Content: View {
-
-   func views() -> [any View] {
-
-      typealias Builder = (Data.Element) -> Content
-      let data = ViewInspection.attribute(label: "data", value: self) as! Data
-      let builder = ViewInspection.attribute(label: "content", value: self) as! Builder
-      let indecies = (0..<data.count).map { i in
-         return data.index(data.startIndex, offsetBy: i)
-      }
-      return indecies.map { builder(data[$0]) }
-   }
-}
diff --git a/Sources/SnapshottingSwift/Snapshots.swift b/Sources/SnapshottingSwift/Snapshots.swift
@@ -120,15 +120,11 @@ class Snapshots {
   }
 
   @MainActor func display(preview: SnapshotPreviewsCore.Preview, completion: @escaping (Result<UIImage, Error>, Float?) -> Void) throws {
-    var view = try preview.view()
-    let supportsExpansion = ViewInspection.shouldExpand(view)
-    let renderingMode = ViewInspection.renderingMode(of: view)
+    var view = preview.view()
     view = AnyView(PreferredColorSchemeWrapper { view })
     view.snapshot(
       layout: preview.layout,
       window: window,
-      legacySupportsExpansion: supportsExpansion,
-      legacyRenderingMode: renderingMode,
       async: false,
       completion: completion)
   }