橋接模式lua實現

--[[
	橋接模式：將抽象部分與它的實現部分分離，使它們都可以獨立地變化。
	其實橋接模式在開發應用中使用的非常廣泛，甚至即使我們沒有學過橋接模式，也可能會潛意識地使用到。
	例如：在游戲開發中，玩家類(Role)合成了背包(Knapsack)；在背包類(Knapsack)中，又合成的物品(Item)；其實這種合成就是橋接模式中的”橋“。注意的是這裡是合成，而不是繼承！
	下面以手機為例
]]--


System = {}

function System:new(n)
	o = {}
	setmetatable(o,self)
	self.__index = self
	o.phonename = n
	return o;
end

function System:GetSystem()
	if self.phonename == "Iphone5s" then
		return "IOS 7"
	elseif self.phonename == "Lumia1020" then
		return "WP 8"
	end
end

CPU = {}

function CPU:new(n)
	o = {}
	setmetatable(o,self)
	self.__index = self
	o.phonename = n
	return o;
end

function CPU:GetCPU()
	if self.phonename == "Iphone5s" then
		return "蘋果 A7/M7協處理器"
	elseif self.phonename == "Lumia1020" then
		return "高通 Adreno 225"
	end
end

Memory = {}

function Memory:new(n)
	o = {}
	setmetatable(o,self)
	self.__index = self
	o.phonename = n
	return o;
end

function Memory:GetMemory()
	if self.phonename == "Iphone5s" then
		return "RAM容量：1GB "
	elseif self.phonename == "Lumia1020" then
		return "RAM容量：2GB"
	end
end


Cellphone = {}

function Cellphone:new(n,o)
	o = o or {}
	setmetatable(o,self)
	self.__index = self
	self.system = System:new(n)
	self.cpu = CPU:new(n)
	self.memory = Memory:new(n)
	self.phonename = n
	return o;
end

function Cellphone:ShowDetail()
	print(self.phonename)
	print(self.system:GetSystem())
	print(self.cpu:GetCPU())
	print(self.memory:GetMemory())
end

Iphone5s = Cellphone:new()

function Iphone5s:Description()
	print("就三個字，'土豪金'")
end

Lumia1020 = Cellphone:new()

function Lumia1020:Description()
	print("最好的相機手機，諾基亞，質量的保證")
end


phone = Iphone5s:new("Iphone5s")
phone:Description()
phone:ShowDetail()


phone = Lumia1020:new("Lumia1020")
phone:Description()
phone:ShowDetail()