Simple Menu Api

os.loadAPI("/rom/apis/colors")

--[[ Variables ]]--
local offset = 0
local sel = 1
local printThanks = false

local bgColour, textColour, selectedBgColour, selectedTextColour

if term.isColour() then
bgColour = colors.white
textColour = colors.gray
selectedBgColour = colors.lightBlue
selectedTextColour = colors.white
else
bgColour = colors.white
textColour = colors.black
selectedBgColour = colors.black
selectedTextColour = colors.white
end

local maxX, maxY = term.getSize()
local running

--[[ Functions ]]--

clear = function()
term.clear()
term.setCursorPos(1,1)
end

local function centerWrite(txt)
local x, y = term.getCursorPos()
term.setCursorPos(math.floor(maxX/2-#tostring(txt)/2),y)
write(txt)
end

local function redraw(tbl, sel, offset)
term.setBackgroundColour(bgColour)
clear()
for i=1, maxY do
  if tbl[i] ~= nil then
   term.setCursorPos(1, i)
   if (i+offset) == sel then
	term.setBackgroundColour(selectedBgColour)
	term.clearLine()
	term.setTextColour(selectedTextColour)
	centerWrite("[ "..tbl[i + offset].text.." ]")
   else
	term.setBackgroundColour(bgColour)
	term.clearLine()
	term.setTextColour(textColour)
	centerWrite(tbl[i + offset].text)
   end
  end
end
end

local function checkTable(tbl)
for i,v in ipairs(tbl) do
  if v.handler == nil or type(v.handler) ~= "function" then
   if term.isColour() then
	term.setTextColour(colors.red)
   end
   print("Menu item \""..i.."\" has no valid handler!")
   local txt = textutils.serialize(tostring(v.handler))
   error("handler = "..txt, 0)
  elseif v.text == nil then
   if term.isColour() then
	term.setTextColour(colors.red)
   end
   print("Menu item \""..i.."\" has no text!")
   local txt = textutils.serialize(tostring(v.text))
   error("text = "..txt, 0)
  end
end
end

runMenu = function(tbl)
if type(tbl) ~= "table" then
  error("Invalid arguments!\nUsage: menuApi.runMenu(menu_table)", 0)
elseif #tbl < 2 then
  error("Not enough items in menu!\nAt least 2 items are required!", 0)
end

checkTable(tbl)

running = true
while running do
  term.setCursorBlink(false)
  os.queueEvent("")
  os.pullEvent()
  redraw(tbl, sel, offset)
  local ev = {os.pullEvent()}
  if ev[1] == "key" then
   if ev[2] == keys.up then
	if sel > 1 then sel = sel - 1 end
	if offset > 0 then offset = offset - 1 end
   elseif ev[2] == keys.down then
	if sel < #tbl then sel = sel + 1 end
	if offset < math.max(#tbl - maxY, 0) then offset = offset + 1 end
   elseif ev[2] == keys.enter then
	term.setBackgroundColour(colors.black)
	term.setTextColour(colors.white)
	clear()
	tbl[sel].handler()  
   end
  elseif ev[1] == "mouse_scroll" then
   if ev[2] == -1 then
	if sel > 1 then sel = sel - 1 end
	if offset > 0 then offset = offset - 1 end
   elseif ev[2] == 1 then
	if sel < #tbl then sel = sel + 1 end
	if offset < math.max(#tbl - maxY, 0) then offset = offset + 1 end
   end
  elseif ev[1] == "mouse_click" then
   if tbl[(ev[4] + offset)] ~= nil then
	sel = ev[4] + offset
	redraw(tbl, sel, offset)
	sleep(.1)
	term.setBackgroundColour(colors.black)
	term.setTextColour(colors.white)
	clear()
	tbl[(ev[4] + offset)].handler()
   end
  end
end
end

stopMenu = function()
running = false
term.setBackgroundColour(colors.black)
if printThanks == true then
  if term.isColour() == true then
   term.setTextColour(colors.yellow)
  end
  clear()
  centerWrite("Thank you for using HD's menu api.")
  print("")
else
  clear()
end
end

listMethods = function()
local tmp = {}
for i,v in pairs(menuApi) do
  table.insert(tmp, i.."()")
end
textutils.pagedTabulate(tmp)
local tmp = nil
end

local function isColour(color)
if term.isColour() then
  if type(color) == "string" then
   if colors[color] ~= nil then
	return {true, colors[color]}
   else
	return false
   end
  elseif type(color) == "number" then
   if color >= 1 and color <= colors.black then
	return {true, color}
   else
	return false
   end
  else
   return false
  end
else
  return false
end
end

setBackgroundColour = function(color)
local tmp = isColour(color)
if tmp[1] then
  bgColour = tmp[2]
end
end

setBarColour = function(color)
local tmp = isColour(color)
if tmp[1] then
  selectedBgColour = tmp[2]
end
end

setTextColour = function(color)
local tmp = isColour(color)
if tmp[1] then
  textColour = tmp[2]
end
end

setBarTextColour = function(color)
local tmp = isColour(color)
if tmp[1] then
  selectedTextColour = tmp[2]
end
end

setBarTextColor = setBarTextColour
setTextColor = setTextColour
setBarColor = setBarColour
setBackgroundColor = setBackgroundColour

os.loadAPI("menuApi")

local menu = {
[1] = { text = "Lua", handler = function() shell.run("lua") end},
[2] = { text = "Hello", handler = function() shell.run("hello") sleep(1) end},
[3] = { text = "Adventure", handler = function() shell.run("adventure") end},
[4] = { text = "Exit", handler = function() stopMenu() end}
}

runMenu(menu)

function stopMenu()
  repeating = false
  running = false
term.clear()
term.setCursorPos(1,1)
end

function clear()
  term.clear()
  term.setCursorPos(1,1)
end

function runMenu( menu, repeating, selectedItem, tColor )
running = true
--[[ Printing Methods ]]--

function printMenu( menu, D )
  for i=1,#menu do
	if i == selectedItem then
	  if term.isColour() then
		term.setTextColour(D) write(">> ") term.setTextColour(colors.white) write(menu[i].text) term.setTextColour(D) write(" <<") term.setTextColour(colors.white) print("")
	else
	  print(">> "..menu[i].text.." <<")
	end
  else
	print("   "..menu[i].text.."   ")
  end
end

--[[ Handler Methods ]]--

function onKeyPressed( key, menu )
  if key == keys.enter then
		onItemSelected(menu)
  elseif key == keys.up then
		if selectedItem > 1 then
		  selectedItem = selectedItem - 1
		end
  elseif key == keys.down then
		if selectedItem < #menu then
		  selectedItem = selectedItem + 1
		end
	 end	
  end
end

function onItemSelected( menu )
  func = loadstring(menu[selectedItem].handler)
  setfenv(func, getfenv())
  func()
end

function onClick( button, xPos, yPos, menu, D )
if button == 1 then
   if yPos <= #menu then
	 selectedItem = yPos
	 func2 = (menu[selectedItem].handler)
	 setfenv(func2, getfenv())
	 func2()
   else
	 func3 = loadstring(menu[#menu].handler)
	 setfenv(func3, getfenv())
	 func3()
   end
elseif button == 2 then
	if yPos > #menu then
	  yPos = #menu
	end
	selectedItem = yPos
	clear()
	printMenu(menu,D)
end
end

function loadMenu( menu, repeating, D )
  while repeating and running do
   clear()
	printMenu(menu, D)
	term.setCursorPos(50, 1)
	if term.isColour() then
	term.setTextColour(colors.yellow)
	print(selectedItem)
	term.setTextColour(colors.white)
	else
	print(selectedItem)
	end
	event, arg1, arg2, arg3 = os.pullEvent()
	if event=="mouse_click" then
	  onClick( arg1, arg2, arg3, menu, D )
	elseif event == "key" then
	  onKeyPressed( arg1, menu )
	end
  end
end


tColor = string.lower(tColor)
if tColor == "white" then
   D = 1
elseif tColor == "orange" then
   D = 2
elseif tColor == "magenta" then
   D = 4
elseif tColor == "lightblue" then
   D = 8
elseif tColor == "yellow" then
   D = 16
elseif tColor == "lime" then
   D = 32
elseif tColor == "pink" then
   D = 64
elseif tColor == "gray" then
   D = 128
elseif tColor == "lightgray" then
   D = 256
elseif tColor == "cyan" then
   D = 512
elseif tColor == "purple" then
   D = 1024
elseif tColor == "blue" then
   D = 2048
elseif tColor == "brown" then
   D = 4096
elseif tColor == "green" then
   D = 8192
elseif tColor == "red" then
   D = 16384
elseif tColor == "black" then
   D = 32768
elseif tColor ~= "white" or "orange" or "magenta" or "lightblue" or "yellow" or "lime" or "pink" or "gray" or "lightgray" or "cyan" or "purple" or "blue" or "brown" or "green" or "red" or "black" then
  D = 1
end

loadMenu(menu, repeating, D)

end

function setSelectedItem( newSelItem )
  selectedItem = newSelItem
  clear()
end

function subMenu(newMenu, oldMenu, D)
  returnMenu = oldMenu
  stopMenu()
  runMenu(newMenu, true, 1, D)
end

function returnToMenu()
  stopMenu()
  runMenu(returnMenu, true, 1, "lime")
end
[color=#222222]

os.loadAPI("menuAPI")

mainMenu = {
[1] = { text = "Reboot", handler = 'os.reboot()' },
[2] = { text = "Shutdown", handler = 'os.shutdown()' },
[3] = { text = "Lua", handler = 'os.run({}, "rom/programs/lua")'},
[4] = { text = "Stop menu", handler = 'menuAPI.stopMenu()' }
}

menuAPI.runMenu(mainMenu, true, 1, "lime")

menuAPI.runMenu( name_of_menu, true, 1, "color")

menuAPI.stopMenu()

menuAPI.clear()

menuAPI.setSelectedItem( newSelItem )

menuAPI.subMenu(newMenu, oldMenu, "color")