3.桥接模式¶

package bridge

import "fmt"

// 桥接模式分离抽象部分和实现部分。使得两部分独立扩展。

// 定义两种实现类型抽象定义，例如定义电脑接口和定义打印机接口

// 一个类型内部包含方法定义，

// 一个类型内部实现自身业务逻辑

// 客户端实例话对应对象，进行对象任意组合

// 电脑接口
type computer interface {
    print()
    setPrinter(printer)
}

// 打印机接口
type printer interface {
    printFile()
}

type epson struct {
}

func (e *epson) printFile()  {
    fmt.Println("printing by epson printer")
}

type hp struct {
}

func (p *hp) printFile()  {
    fmt.Println("printing by hp printer")
}



type Win struct {
    printer printer
}

func (w *Win) print()  {
    fmt.Println("print win")
    w.printer.printFile()
}

func (w *Win) setPrinter(p printer)  {
    w.printer = p
}

type Mac struct {
    printer printer
}

func (m *Mac) print()  {
    fmt.Println("print mac")
    m.printer.printFile()
}

func (m *Mac) setPrinter(p printer)  {
    m.printer = p
}

package bridge

import (
    "fmt"
    "testing"
)

func TestBridge(t *testing.T)  {
    hpPrinter := &hp{}

    epsonPrinter := &epson{}

    m := Mac{}

    m.setPrinter(hpPrinter)
    m.print()
    m.setPrinter(epsonPrinter)
    m.print()

    fmt.Println("------")

    w := Win{}
    w.setPrinter(epsonPrinter)
    w.print()
    w.setPrinter(hpPrinter)
    w.print()
}

=== RUN   TestBridge
print mac
printing by hp printer
print mac
printing by epson printer
------
print win
printing by epson printer
print win
printing by hp printer
--- PASS: TestBridge (0.00s)
PASS