Computercraft Elevator

--[[ Local variables ]]

local termWidth, termHeight = term.getSize()
local selectedItem = 1
local a = 0 -- Current floor in block height
local b = 0 -- Selected floor in block height
local c = 0 -- Floor block height difference
local d = 0 -- Absolute value of c for timer loop
local running = true

--[[ Menu Methods ]]

function e() -- Math / Timer Function
  if rs.getBundledOutput("back",colors.white)==true then
    a = 0
  elseif rs.getBundledOutput("back",colors.black)== true then
    a = -5
  elseif rs.getBundledOutput("back",colors.red)== true then
    a = -10
  elseif rs.getBundledOutput("back",colors.green)== true then
    a = -15
  end -- Value of a is negative to

  c = a + b
  d = math.abs(c)

  if c > 0 then -- Timer loop to go down
    for x=1, d do
      rs.setBundledOutput("back",colors.combine(rs.getBundledOutput("back"),colors.blue))
      sleep(.2)
      rs.setBundledOutput("back",colors.subtract(rs.getBundledOutput("back"),colors.blue))
      sleep(.2)
    end
  elseif c < 0 then -- Timer loop to go up
    for x=1, d do
      rs.setBundledOutput("back",colors.combine(rs.getBundledOutput("back"),colors.gray))
      sleep(.2)
      rs.setBundledOutput("back",colors.subtract(rs.getBundledOutput("back"),colors.gray))
      sleep(.2)
    end
  elseif c == 0 then
    return
  end
end

function C1() -- Floor selection to give wanted height variable
  if rs.getBundledOutput("back",colors.white)==true then
    return
  else
    b = 0
    e(b)
  end
end

function C2()
  if rs.getBundledOutput("back",colors.black)==true then
    return
  else
    b = 5
    e(b)
  end
end

function C3()
  if rs.getBundledOutput("back",colors.red)==true then
    return
  else
    b = 10
    e(b)
  end
end

function C4()
  if rs.getBundledOutput("back",colors.green)==true then
    return
  else
    b = 15
    e(b)
  end
end

--[[ Menu Definitions ]]

mainMenu = {
  [1] = { text = "1st Floor", handler = C1},
  [2] = { text = "2nd Floor", handler = C2},
  [3] = { text = "3rd Floor", handler = C3},
  [4] = { text = "4th Floor", handler = C4}
}

--[[ Printing Methods ]]

function printMenu( menu )
  term.clear()
  term.setCursorPos(1,1)
  print("-=Please Select a Floor=-")
  term.setCursorPos(1,2)
  for i=1,#menu do
    if i == selectedItem then
      print(">> "..menu[i].text)
    else
      print("   "..menu[i].text)
    end
  end
end

--[[ Handler method ]]

function onKeyPressed(key, menu)
  if key == 28 then
    onItemSelected(menu)
  elseif key == 200 then
    if selectedItem > 1 then
      selectedItem = selectedItem - 1
    end
  elseif key == 208 then
    if selectedItem < #menu then
      selectedItem = selectedItem + 1
    end
  end
end

function onItemSelected( menu )
  menu[selectedItem].handler()
end

--[[ Main method ]]

function main()
    while running do
      printMenu(mainMenu)
      event, key = os.pullEvent("key")
      onKeyPressed(key,mainMenu)
      e()
    end
  end
end
main()