Mob Farms

m = peripheral.wrap("back")
w,h = m.getSize()
w = w+1
h = h+1
page = 1
col = { ["white"]=1, ["orange"]=2, ["magenta"]=4, ["lightblue"]=8, ["yellow"]=16, ["lime"]=32, ["pink"]=64, ["gray"]=128, ["lightgray"]=256, ["cyan"]=512, ["purple"]=1024, ["blue"]=2048, ["brown"]=4096, ["green"]=8192, ["red"]=16384, ["black"]=32768 }
rednet.open("top")
mobfarmsname = { [1]="ZombiePig Farm", [2]="Blaze Farm", }
mobfarmscode = { [1]="zombiepig", [2]="blaze", }
mobfarmsactive = { [1]=false, [2]=false, }
mobfarmsbutton = {}

function swrite(str,x,y,color)
	m.setCursorPos(x,y)
	m.setTextColor(col[color])
	m.write(str)
end

function drawbox(str,x1,x2,y1,y2,strcol,color)
	m.setCursorPos(x1,y1)
	m.setBackgroundColor(col[color])
	m.setTextColor(col[strcol])
	local bw = x2-x1
	local bh = y2-y1
	local bstr = " "
	while #bstr < bw do
		bstr = bstr.." "
	end
	for i=1,bh do
		m.setCursorPos(x1,y1+i-1)
		m.write(bstr)
	end
	m.setCursorPos(x1+bw/2-#str/2,y1+bh/2)
	m.write(str)
	m.setBackgroundColor(col["black"])
	return { [1]=x1, [2]=x2, [3]=y1, [4]=y2 }
end

function press(but)
	if event == "monitor_touch" then
		if pr2 >= but[1] and pr2 < but[2] and pr3 >= but[3] and pr3 < but[4] then
			return true
		else
			return false
		end
	end
end

function drawbackground(str,strcol,color)
	drawbox("",1,w,1,h,strcol,color)
	drawbox("",2,w-1,2,h-1,"black","black")
	drawbox(str,1,w,1,2,strcol,color)
end

function drawmenu()
	m.clear()
	drawbackground("Mob Farms","black","white")
	if page > 1 then
		back = drawbox("Back",4,w/2-2,h-5,h-2,"white","red")
	end
	for i=1,3 do
		if mobfarmsname[i+(page-1)*3] == nil then
			mobfarmsbutton[i+(page-1)*3] = drawbox("",w+4,w+6,4,4,"black","black")
		else
			if mobfarmsactive[i+(page-1)*3] then color = "green" else color = "red" end
			mobfarmsbutton[i+(page-1)*3] = textutils.serialize(drawbox(mobfarmsname[i+(page-1)*3],4,w-3,4*i-1,4*i+2,"white",color))
		end
		if i == 3 and mobfarmsname[i+(page-1)*3+1] ~= nil then
			next = drawbox("Next",w/2+2,w-3,h-5,h-2,"white","green")
		else
			next = drawbox("Next",w/2+2,w-3,h+5,h+2,"white","green")
		end
	end
end

function updatemobfarms()
	for i=1,#mobfarmsactive do
		if mobfarmsactive[i] then
			rednet.broadcast(mobfarmscode[i].."on")
		else
			rednet.broadcast(mobfarmscode[i].."off")
		end
	end
	drawmenu()
end

drawmenu()
updatemobfarms()

while true do
	event,pr1,pr2,pr3 = os.pullEvent()
	for i=1,3 do
		if mobfarmsname[i+(page-1)*3] ~= nil then
			if press(textutils.unserialize(mobfarmsbutton[i+(page-1)*3])) then
				mobfarmsactive[i+(page-1)*3] = not mobfarmsactive[i+(page-1)*3]
				updatemobfarms()
			end
		end
	end
	if page > 1 then
		if press(back) then
			page = page - 1
			drawmenu()
		end
	end
	if press(next) then
		page = page + 1
		drawmenu()
	end
end