👔LeftArrowShape

LeftArrowShape (Shape)

👔 LeftArrowShape

⬆️ 需要： Vector2D, path.line()

import SwiftUI
import Vector2D                         // ⭐️ support vector operations

struct LeftArrowShape: Shape {
    func path(in rect: CGRect) -> Path {
        Path { p in
            let k: CGFloat = 5           // arrowhead scale
            let A = rect.left + [2,0]    // arrowhead point
            p.line(A, A + k * [1, -1])   // 👔 Vector2D, 🌀 Path+ext
            p.line(A, A + k * [1,  1])
            p.line(A, rect.right)
        }
    }
}

⬆️ 需要

• Vector2D

• Path+

⬇️ 應用

• LeftArrow

👥 相關

• used by LeftArrow to draw a visible left arrow.

• needs Vector2D to do vector operations.

• uses path.line() to draw line segments.

📗 參考

• Thinking in SwiftUI ⟩ Ch.4 Layout ⟩ Grid Views ⭐️