CC Tweaked Client App - AppStore - text editor

--this program is a text Editor
local w, h = term.getSize()
local OpenedFile = "n"
local FileData = {}
local OpenedPath = "os"
local PathParts = {"os"}
local PathSection = 1

local function Clear()
term.setBackgroundColor(colors.black)
term.clear()
term.setCursorPos(1,1)
end

local function CenterText(y,text)
    local x = math.floor((w - string.len(text)) /2)
    term.setCursorPos(x,y)
    term.clearLine()
    term.write(text)
end

local function OpenFile(file)
local Item = fs.open(file,"r")
local line
while true do
    line = Item.readLine()
    if line == nil then
        break
    else
        FileData[#FileData + 1] = line
    end
end
Item.close()
EditorMenu()
end

local function SaveFile(file)
local Item = fs.open(file,"w")
Item.clear()
Item.setCursorPos(1,1)
for i = 1, #FileData do
    Item.writeLine(FileData[i])
end
Item.close()
end

function EditorMenu()
Clear()
print(OpenedFile)
local Options = {"=Exit=","=Save="}
for i = 1, #FileData do
    Options[#Options + 1] = FileData[i]
end
local n = CUI(Options,2)
if Options[n] == "=Exit=" then
    FileData = {}
    OpenedFile = "n"
    FileNavigator()
elseif Options[n] == "=Save=" then
    SaveFile(OpenedFile)
else
    local event
    input = FileData[n]
    while true do
        event = {os.pullEvent("key")}
        input = read
        if event[2] == keys.enter then break end
    end
    FileData[n] = input
    EditorMenu()
end
end

function CUI(m,y) --declare function
n=1
local l = #m
while true do
term.setCursorPos(1,y)
term.clearLine()
for i = 1, #m do

if i==n then print("["..m[i].."]") else print(m[i]) end
end
if b==keys.a and n>1 then n=n-1 end
if b==keys.d and n<l then n=n+1 end
if b==keys.enter then break end
end
return n --return the value
end

function FileNavigator()
Clear()
print(OpenedPath)
Files = {fs.list(OpenedPath)}
local Options = {"exit","return"}
for i = 1, #Files do
    Options[#Options + 1] = Files[i]
end
local n = CUI(Options,2)
if Options[n] == "exit" then
    shell.run(settings.get("os_DesktopLoc"))
elseif Options[n] == "return" then
    OpenedPath = PathPart[PathSection-1]
else
    if fs.isDir(Options[n]) == true then
        OpenedPath = Options[n]
    else
        OpenedFile = Options[n]
        OpenFile(Options[n])
    end
end
end