Golang桥接模式：抽象与实现分离详解

type Renderer interface {
    RenderCircle(radius float64)
    RenderSquare(side float64)
}

type WindowsRenderer struct{}

func (w *WindowsRenderer) RenderCircle(radius float64) {
    fmt.Printf("Windows上绘制半径为%.2f的圆\n", radius)
}

func (w *WindowsRenderer) RenderSquare(side float64) {
    fmt.Printf("Windows上绘制边长为%.2f的正方形\n", side)
}

type MacRenderer struct{}

func (m *MacRenderer) RenderCircle(radius float64) {
    fmt.Printf("Mac上绘制半径为%.2f的圆\n", radius)
}

func (m *MacRenderer) RenderSquare(side float64) {
    fmt.Printf("Mac上绘制边长为%.2f的正方形\n", side)
}

type Shape struct {
    renderer Renderer
}

func NewShape(renderer Renderer) *Shape {
    return &Shape{renderer: renderer}
}

type Circle struct {
    *Shape
    radius float64
}

func NewCircle(renderer Renderer, radius float64) *Circle {
    return &Circle{
        Shape:  NewShape(renderer),
        radius: radius,
    }
}

func (c *Circle) Draw() {
    c.Shape.renderer.RenderCircle(c.radius)
}

func main() {
    var renderer Renderer

    // 根据系统决定使用哪种渲染器
    if runtime.GOOS == "windows" {
        renderer = &WindowsRenderer{}
    } else {
        renderer = &MacRenderer{}
    }

    circle := NewCircle(renderer, 5.0)
    circle.Draw()
}