Add ClipEffect interface (#98)

Sources/OpenSwiftUI/View/Modifier/ClipEffect.swift

@@ -0,0 +1,130 @@
+import Foundation
+
+// MARK: - ClipEffect
+
+@frozen
+public struct _ClipEffect<ClipShape> where ClipShape: Shape {
+    public var shape: ClipShape
+    public var style: FillStyle
+
+    @inlinable
+    public init(shape: ClipShape, style: FillStyle = FillStyle()) {
+        self.shape = shape
+        self.style = style
+    }
+
+    public var animatableData: ClipShape.AnimatableData {
+        get { shape.animatableData }
+        set { shape.animatableData = newValue }
+    }
+
+    public typealias AnimatableData = ClipShape.AnimatableData
+    public typealias Body = Swift.Never
+}
+
+// FIXME
+extension _ClipEffect: PrimitiveViewModifier {}
+
+// MARK: - View Extension
+
+extension View {
+
+    /// Sets a clipping shape for this view.
+    ///
+    /// Use `clipShape(_:style:)` to clip the view to the provided shape. By
+    /// applying a clipping shape to a view, you preserve the parts of the view
+    /// covered by the shape, while eliminating other parts of the view. The
+    /// clipping shape itself isn't visible.
+    ///
+    /// For example, this code applies a circular clipping shape to a `Text`
+    /// view:
+    ///
+    ///     Text("Clipped text in a circle")
+    ///         .frame(width: 175, height: 100)
+    ///         .foregroundColor(Color.white)
+    ///         .background(Color.black)
+    ///         .clipShape(Circle())
+    ///
+    /// The resulting view shows only the portion of the text that lies within
+    /// the bounds of the circle.
+    ///
+    /// ![A screenshot of text clipped to the shape of a
+    /// circle.](OpenSwiftUI-View-clipShape.png)
+    ///
+    /// - Parameters:
+    ///   - shape: The clipping shape to use for this view. The `shape` fills
+    ///     the view's frame, while maintaining its aspect ratio.
+    ///   - style: The fill style to use when rasterizing `shape`.
+    ///
+    /// - Returns: A view that clips this view to `shape`, using `style` to
+    ///   define the shape's rasterization.
+    @inlinable
+    public func clipShape<S>(_ shape: S, style: FillStyle = FillStyle()) -> some View where S: Shape {
+        modifier(_ClipEffect(shape: shape, style: style))
+    }
+
+
+    /// Clips this view to its bounding rectangular frame.
+    ///
+    /// Use the `clipped(antialiased:)` modifier to hide any content that
+    /// extends beyond the layout bounds of the shape.
+    ///
+    /// By default, a view's bounding frame is used only for layout, so any
+    /// content that extends beyond the edges of the frame is still visible.
+    ///
+    ///     Text("This long text string is clipped")
+    ///         .fixedSize()
+    ///         .frame(width: 175, height: 100)
+    ///         .clipped()
+    ///         .border(Color.gray)
+    ///
+    /// ![Screenshot showing text clipped to its
+    /// frame.](OpenSwiftUI-View-clipped.png)
+    ///
+    /// - Parameter antialiased: A Boolean value that indicates whether the
+    ///   rendering system applies smoothing to the edges of the clipping
+    ///   rectangle.
+    ///
+    /// - Returns: A view that clips this view to its bounding frame.
+    @inlinable
+    public func clipped(antialiased: Bool = false) -> some View {
+        clipShape(
+            Rectangle(),
+            style: FillStyle(antialiased: antialiased)
+        )
+    }
+
+
+    /// Clips this view to its bounding frame, with the specified corner radius.
+    ///
+    /// By default, a view's bounding frame only affects its layout, so any
+    /// content that extends beyond the edges of the frame remains visible. Use
+    /// `cornerRadius(_:antialiased:)` to hide any content that extends beyond
+    /// these edges while applying a corner radius.
+    ///
+    /// The following code applies a corner radius of 25 to a text view:
+    ///
+    ///     Text("Rounded Corners")
+    ///         .frame(width: 175, height: 75)
+    ///         .foregroundColor(Color.white)
+    ///         .background(Color.black)
+    ///         .cornerRadius(25)
+    ///
+    /// ![A screenshot of a rectangle with rounded corners bounding a text
+    /// view.](OpenSwiftUI-View-cornerRadius.png)
+    ///
+    /// - Parameter antialiased: A Boolean value that indicates whether the
+    ///   rendering system applies smoothing to the edges of the clipping
+    ///   rectangle.
+    ///
+    /// - Returns: A view that clips this view to its bounding frame with the
+    ///   specified corner radius.
+    @available(*, deprecated, message: "Use `clipShape` or `fill` instead.")
+    @inlinable
+    public func cornerRadius(_ radius: CGFloat, antialiased: Bool = true) -> some View {
+        clipShape(
+            RoundedRectangle(cornerRadius: radius),
+            style: FillStyle(antialiased: antialiased)
+        )
+    }
+}

Sources/OpenSwiftUI/View/Shape/RoundedCornerStyle.swift

@@ -0,0 +1,18 @@
+//
+//  ShapeRole.swift
+//  OpenSwiftUI
+//
+//  Audited for RELEASE_2021
+//  Status: Complete
+
+/// Defines the shape of a rounded rectangle's corners.
+public enum RoundedCornerStyle: Sendable {
+    /// Quarter-circle rounded rect corners.
+    case circular
+
+    /// Continuous curvature rounded rect corners.
+    case continuous
+}
+
+extension RoundedCornerStyle: Equatable {}
+extension RoundedCornerStyle: Hashable {}

Sources/OpenSwiftUI/View/Shape/RoundedRectangle.swift

@@ -0,0 +1,30 @@
+import Foundation
+
+@frozen
+public struct RoundedRectangle: Shape {
+    public var cornerSize: CGSize
+    public var style: RoundedCornerStyle
+
+    @inlinable
+    public init(cornerSize: CGSize, style: RoundedCornerStyle = .circular) {
+        self.cornerSize = cornerSize
+        self.style = style
+    }
+
+    @inlinable
+    public init(cornerRadius: CGFloat, style: RoundedCornerStyle = .circular) {
+        let cornerSize = CGSize(width: cornerRadius, height: cornerRadius)
+        self.init(cornerSize: cornerSize, style: style)
+    }
+
+    public func path(in rect: CGRect) -> Path {
+        fatalError("TODO")
+    }
+    public var animatableData: CGSize.AnimatableData {
+        get { cornerSize.animatableData }
+        set { cornerSize.animatableData = newValue }
+    }
+
+    public typealias Body = _ShapeView<RoundedRectangle, ForegroundStyle>
+}
+

Sources/OpenSwiftUI/View/Shape/StrokeStyle.swift

@@ -5,6 +5,7 @@
 //  Audited for RELEASE_2021
 //  Status: Complete
 
+import Foundation
 #if canImport(CoreGraphics)
 import CoreGraphics
 #else