add mediator

Author: senghoo

08_mediator/README.md

@@ -0,0 +1,7 @@
+# 中介者模式
+
+中介者模式封装对象之间互交，使依赖变的简单，并且使复杂互交简单化，封装在中介者中。
+
+例子中的中介者使用单例模式生成中介者。
+
+中介者的change使用switch判断类型。

08_mediator/mediator.go

@@ -0,0 +1,77 @@
+package mediator
+
+import (
+	"fmt"
+	"strings"
+)
+
+type CDDriver struct {
+	Data string
+}
+
+func (c *CDDriver) ReadData() {
+	c.Data = "music,image"
+
+	fmt.Printf("CDDriver: reading data %s\n", c.Data)
+	GetMediatorInstance().changed(c)
+}
+
+type CPU struct {
+	Video string
+	Sound string
+}
+
+func (c *CPU) Process(data string) {
+	sp := strings.Split(data, ",")
+	c.Sound = sp[0]
+	c.Video = sp[1]
+
+	fmt.Printf("CPU: split data with Sound %s, Video %s\n", c.Sound, c.Video)
+	GetMediatorInstance().changed(c)
+}
+
+type VideoCard struct {
+	Data string
+}
+
+func (v *VideoCard) Display(data string) {
+	v.Data = data
+	fmt.Printf("VideoCard: display %s\n", v.Data)
+	GetMediatorInstance().changed(v)
+}
+
+type SoundCard struct {
+	Data string
+}
+
+func (s *SoundCard) Play(data string) {
+	s.Data = data
+	fmt.Printf("SoundCard: play %s\n", s.Data)
+	GetMediatorInstance().changed(s)
+}
+
+type Mediator struct {
+	CD    *CDDriver
+	CPU   *CPU
+	Video *VideoCard
+	Sound *SoundCard
+}
+
+var mediator *Mediator
+
+func GetMediatorInstance() *Mediator {
+	if mediator == nil {
+		mediator = &Mediator{}
+	}
+	return mediator
+}
+
+func (m *Mediator) changed(i interface{}) {
+	switch inst := i.(type) {
+	case *CDDriver:
+		m.CPU.Process(inst.Data)
+	case *CPU:
+		m.Sound.Play(inst.Sound)
+		m.Video.Display(inst.Video)
+	}
+}

08_mediator/mediator_test.go

@@ -0,0 +1,34 @@
+package mediator
+
+import "testing"
+
+func TestMediator(t *testing.T) {
+	mediator := GetMediatorInstance()
+	mediator.CD = &CDDriver{}
+	mediator.CPU = &CPU{}
+	mediator.Video = &VideoCard{}
+	mediator.Sound = &SoundCard{}
+
+	//Tiggle
+	mediator.CD.ReadData()
+
+	if mediator.CD.Data != "music,image" {
+		t.Fatalf("CD unexpect data %s", mediator.CD.Data)
+	}
+
+	if mediator.CPU.Sound != "music" {
+		t.Fatalf("CPU unexpect sound data %s", mediator.CPU.Sound)
+	}
+
+	if mediator.CPU.Video != "image" {
+		t.Fatalf("CPU unexpect video data %s", mediator.CPU.Video)
+	}
+
+	if mediator.Video.Data != "image" {
+		t.Fatalf("VidoeCard unexpect data %s", mediator.Video.Data)
+	}
+
+	if mediator.Sound.Data != "music" {
+		t.Fatalf("SoundCard unexpect data %s", mediator.Sound.Data)
+	}
+}