Elevator

--[[Preferences]]--
local bColor = colors.cyan -- Background Color
local tColor = colors.gray  -- Text Color.  Change colors to preference.
rednet.open("right") -- Change side to whichever your modem is on

--[[Code]]--
local w,h = term.getSize() -- Gets size of screen and sets it to w and h
local selection = 1  -- Used to keep track of the menu
local string, ypos, event, id, x, y, result -- Stating variables
local function printCentered(string, ypos)
  term.setCursorPos(w/2-#string/2, ypos) -- Sets cursor to print the string, centered and at the given y position.
  term.write(string)
end
local function drawGUI()
  term.setBackgroundColor(bColor)
  term.setTextColor(tColor)  -- These might error, I've never done this before.  If they do, just change bColor and tColor to whatever you would like. 
  term.clear()
  printCentered("Elevator Control", 1)
  printCentered(string.rep("-", w), 2) -- string.rep repeats the string a number of times, in this case, w, the width of the screen.
  printCentered("Floor 1", 8)
  printCentered("Floor 2", 13)  --Change the strings to whatever you would like for your options.
  if selection == 1 then ypos = 9 else ypos = 14 end -- Depending on the selection, print a line beneath an option.
  printCentered("---------", ypos)
end
local function main()
  while true do do -- Repeat forever
   result = nil -- Resetting the result of the operation
    drawGUI()
    event, id, x, y = os.pullEvent() -- Wait for something to happen, then record it.
    if event == "mouse_click" then -- If the mouse clicked...
	  if x >= w/2-3 and x <= w/2+3 then -- if it was within the x of the buttons...
	    if y == 8 then -- if it was option 1...
		  if selection ~= 1 then selection = 1 else result = 1 end -- If it wasn't selected, select it.  If it was, choose it.
	    end
	  else
		 if y == 13
		   if selection ~= 2 then selection = 2 else result = 2 end -- Same as above.
	    end
	  end
    elseif event == "key" then  -- If a key was pressed...
	  if id == 28 then  -- If it was enter...
	    result = selection
	  elseif id == 200 then  -- If it was down arrow...
	    if selection ~= 2 then selection = 2 end
	   elseif id == 208 then  -- If it was up arrow...
	    if selection ~= 1 then selection = 1 end
	   end
    end
    if result ~= nil then rednet.broadcast(tostring(result)) end  -- Broadcast the result of the menu.
  end
end
main()

rednet.open("right") -- Again, change side to whichever your modem is on.
local sender, message, distance -- Declaring variables

while true do
   sender, message, distance = os.pullEvent("rednet_message") -- Wait for a message
   if message == "1" then
	 -- Command for floor 1
   elseif message == "2" then
	  -- Command for floor 2
   end
end