Add Primary/Secondary/Tertiary/QuaternaryContentStyle (#419)

Sources/TokamakCore/Shapes/ShapeStyles/BackgroundStyle.swift

@@ -74,6 +74,9 @@ public extension View {
   }
 
   public func modifyEnvironment(_ values: inout EnvironmentValues) {
-    values._backgroundStyle = .init(styles: [style, style, style], environment: values)
+    values._backgroundStyle = .init(
+      styles: (primary: style, secondary: style, tertiary: style),
+      environment: values
+    )
   }
 }

Sources/TokamakCore/Shapes/ShapeStyles/ContentStyles.swift

@@ -0,0 +1,104 @@
+// Copyright 2020-2021 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//  Created by Carson Katri on 7/7/21.
+//
+
+@frozen public struct PrimaryContentStyle {
+  @inlinable
+  public init() {}
+}
+
+extension PrimaryContentStyle: ShapeStyle {
+  public func _apply(to shape: inout _ShapeStyle_Shape) {
+    if !shape.inRecursiveStyle,
+       let foregroundStyle = shape.environment._foregroundStyle
+    {
+      if foregroundStyle.styles.primary is Self {
+        shape.inRecursiveStyle = true
+      }
+      foregroundStyle.styles.primary._apply(to: &shape)
+    } else {
+      shape.result = .color(shape.environment.foregroundColor ?? .primary)
+    }
+  }
+
+  public static func _apply(to shape: inout _ShapeStyle_ShapeType) {}
+}
+
+@frozen public struct SecondaryContentStyle {
+  @inlinable
+  public init() {}
+}
+
+extension SecondaryContentStyle: ShapeStyle {
+  public func _apply(to shape: inout _ShapeStyle_Shape) {
+    if !shape.inRecursiveStyle,
+       let foregroundStyle = shape.environment._foregroundStyle
+    {
+      if foregroundStyle.styles.secondary is Self {
+        shape.inRecursiveStyle = true
+      }
+      foregroundStyle.styles.secondary._apply(to: &shape)
+    } else {
+      shape.result = .color((shape.environment.foregroundColor ?? .primary).opacity(0.5))
+    }
+  }
+
+  public static func _apply(to shape: inout _ShapeStyle_ShapeType) {}
+}
+
+@frozen public struct TertiaryContentStyle {
+  @inlinable
+  public init() {}
+}
+
+extension TertiaryContentStyle: ShapeStyle {
+  public func _apply(to shape: inout _ShapeStyle_Shape) {
+    if !shape.inRecursiveStyle,
+       let foregroundStyle = shape.environment._foregroundStyle
+    {
+      if foregroundStyle.styles.tertiary is Self {
+        shape.inRecursiveStyle = true
+      }
+      foregroundStyle.styles.tertiary._apply(to: &shape)
+    } else {
+      shape.result = .color((shape.environment.foregroundColor ?? .primary).opacity(0.3))
+    }
+  }
+
+  public static func _apply(to shape: inout _ShapeStyle_ShapeType) {}
+}
+
+@frozen public struct QuaternaryContentStyle {
+  @inlinable
+  public init() {}
+}
+
+extension QuaternaryContentStyle: ShapeStyle {
+  public func _apply(to shape: inout _ShapeStyle_Shape) {
+    if !shape.inRecursiveStyle,
+       let foregroundStyle = shape.environment._foregroundStyle
+    {
+      if foregroundStyle.styles.tertiary is Self {
+        shape.inRecursiveStyle = true
+      }
+      foregroundStyle.styles.tertiary._apply(to: &shape)
+    } else {
+      shape.result = .color((shape.environment.foregroundColor ?? .primary).opacity(0.2))
+    }
+  }
+
+  public static func _apply(to shape: inout _ShapeStyle_ShapeType) {}
+}

Sources/TokamakCore/Shapes/ShapeStyles/ForegroundStyle.swift

@@ -60,24 +60,36 @@ public extension View {
   }
 
   @inlinable
-  func foregroundStyle<S1, S2, S3>(_ primary: S1, _ secondary: S2,
-                                   _ tertiary: S3) -> some View
+  func foregroundStyle<S1, S2, S3>(
+    _ primary: S1,
+    _ secondary: S2,
+    _ tertiary: S3
+  ) -> some View
     where S1: ShapeStyle, S2: ShapeStyle, S3: ShapeStyle
   {
-    modifier(_ForegroundStyleModifier(styles: [primary, secondary, tertiary]))
+    modifier(_ForegroundStyleModifier(primary: primary, secondary: secondary, tertiary: tertiary))
   }
 }
 
-@frozen public struct _ForegroundStyleModifier: ViewModifier, EnvironmentModifier {
-  public var styles: [ShapeStyle]
+@frozen public struct _ForegroundStyleModifier<Primary, Secondary, Tertiary>: ViewModifier,
+  EnvironmentModifier
+  where Primary: ShapeStyle, Secondary: ShapeStyle, Tertiary: ShapeStyle
+{
+  public var primary: Primary
+  public var secondary: Secondary
+  public var tertiary: Tertiary
 
   @inlinable
-  public init(styles: [ShapeStyle]) {
-    self.styles = styles
+  public init(
+    primary: Primary,
+    secondary: Secondary,
+    tertiary: Tertiary
+  ) {
+    (self.primary, self.secondary, self.tertiary) = (primary, secondary, tertiary)
   }
 
   public typealias Body = Never
   public func modifyEnvironment(_ values: inout EnvironmentValues) {
-    values._foregroundStyle = .init(styles: styles, environment: values)
+    values._foregroundStyle = .init(styles: (primary, secondary, tertiary), environment: values)
   }
 }

Sources/TokamakCore/Shapes/ShapeStyles/ShapeStyle.swift

@@ -23,23 +23,23 @@ public protocol ShapeStyle {
 }
 
 public struct AnyShapeStyle: ShapeStyle {
-  let styles: [ShapeStyle]
+  let styles: (primary: ShapeStyle, secondary: ShapeStyle, tertiary: ShapeStyle)
+  var stylesArray: [ShapeStyle] {
+    [styles.primary, styles.secondary, styles.tertiary]
+  }
+
   let environment: EnvironmentValues
 
   public func _apply(to shape: inout _ShapeStyle_Shape) {
     shape.environment = environment
-    if styles.count > 1 {
-      let results = styles.map { style -> _ShapeStyle_Shape.Result in
-        var copy = shape
-        style._apply(to: &copy)
-        return copy.result
-      }
-      shape
-        .result =
-        .resolved(.array(results.compactMap { $0.resolvedStyle(on: shape, in: environment) }))
-    } else if let first = styles.first {
-      first._apply(to: &shape)
+    let results = stylesArray.map { style -> _ShapeStyle_Shape.Result in
+      var copy = shape
+      style._apply(to: &copy)
+      return copy.result
     }
+    shape
+      .result =
+      .resolved(.array(results.compactMap { $0.resolvedStyle(on: shape, in: environment) }))
 
     switch shape.operation {
     case let .prepare(text, level):
@@ -50,7 +50,9 @@ public struct AnyShapeStyle: ShapeStyle {
       shape.result = .prepared(Text(storage: text.storage, modifiers: modifiers))
     case let .resolveStyle(levels):
       if case let .resolved(resolved) = shape.result {
-        if case let .array(children) = resolved {
+        if case let .array(children) = resolved,
+           children.count >= levels.upperBound
+        {
           shape.result = .resolved(.array(.init(children[levels])))
         }
       } else if let resolved = shape.result.resolvedStyle(on: shape, in: environment) {

Sources/TokamakDOM/Core.swift

@@ -83,7 +83,16 @@ public typealias Rectangle = TokamakCore.Rectangle
 public typealias RoundedRectangle = TokamakCore.RoundedRectangle
 public typealias ContainerRelativeShape = TokamakCore.ContainerRelativeShape
 
+// MARK: Shape Styles
+
+public typealias PrimaryContentStyle = TokamakCore.PrimaryContentStyle
+public typealias SecondaryContentStyle = TokamakCore.SecondaryContentStyle
+public typealias TertiaryContentStyle = TokamakCore.TertiaryContentStyle
+public typealias QuaternaryContentStyle = TokamakCore.QuaternaryContentStyle
+
 public typealias ForegroundStyle = TokamakCore.ForegroundStyle
+public typealias BackgroundStyle = TokamakCore.BackgroundStyle
+
 public typealias Material = TokamakCore.Material
 
 // MARK: Primitive values

Sources/TokamakDemo/ShapeStyleDemo.swift

@@ -89,6 +89,18 @@ struct ShapeStyleDemo: View {
         }
       }
     }
+    HStack {
+      VStack {
+        Text("Primary")
+          .foregroundStyle(PrimaryContentStyle())
+        Text("Secondary")
+          .foregroundStyle(SecondaryContentStyle())
+        Text("Tertiary")
+          .foregroundStyle(TertiaryContentStyle())
+        Text("Quaternary")
+          .foregroundStyle(QuaternaryContentStyle())
+      }
+    }
     #endif
   }
 }

Sources/TokamakStaticHTML/Core.swift

@@ -44,7 +44,16 @@ public typealias Rectangle = TokamakCore.Rectangle
 public typealias RoundedRectangle = TokamakCore.RoundedRectangle
 public typealias ContainerRelativeShape = TokamakCore.ContainerRelativeShape
 
+// MARK: Shape Styles
+
+public typealias PrimaryContentStyle = TokamakCore.PrimaryContentStyle
+public typealias SecondaryContentStyle = TokamakCore.SecondaryContentStyle
+public typealias TertiaryContentStyle = TokamakCore.TertiaryContentStyle
+public typealias QuaternaryContentStyle = TokamakCore.QuaternaryContentStyle
+
 public typealias ForegroundStyle = TokamakCore.ForegroundStyle
+public typealias BackgroundStyle = TokamakCore.BackgroundStyle
+
 public typealias Material = TokamakCore.Material
 
 // MARK: Primitive values

Tests/TokamakStaticHTMLTests/RenderingTests.swift

@@ -200,6 +200,28 @@ final class RenderingTests: XCTestCase {
     )
   }
 
+  func testContentStyles() {
+    assertSnapshot(
+      matching: HStack {
+        Rectangle()
+          .frame(width: 50, height: 50)
+          .foregroundStyle(PrimaryContentStyle())
+        Rectangle()
+          .frame(width: 50, height: 50)
+          .foregroundStyle(SecondaryContentStyle())
+        Rectangle()
+          .frame(width: 50, height: 50)
+          .foregroundStyle(TertiaryContentStyle())
+        Rectangle()
+          .frame(width: 50, height: 50)
+          .foregroundStyle(QuaternaryContentStyle())
+      }
+      .foregroundColor(.blue),
+      as: .image(size: .init(width: 275, height: 100)),
+      timeout: defaultSnapshotTimeout
+    )
+  }
+
   func testMaterial() {
     assertSnapshot(
       matching: ZStack {