[1.46][Example] Simple mouse controlled menu

--[[		MOUSE MENU TUTORIAL	 ]]--	
--[[ Copyright © 2012 InputUsername ]]--

--[[
State is the variable representing the current menu.
It can be anything as long as it's a string.
It is easier if you keep the string 'state' as short as possible.
]]--
local state = "main"


--[[
Here we define a table containing the options for
the main menu and the menu on the 'info' screen.
]]--
local tMainOptions = { "[ Play ]", "[ Info ]", "[ Quit ]" }
local tInfoOptions = { "[ Credits ]", "[ Back ]" }


--[[
The following lines of code are function definitions for the
draw functions of the menu.
]]--

local function drawMain() -- defines the drawMain function, which obviously draws the main menu

  term.clear()

  term.setCursorPos(2,1)
  term.write("Mouse menu tutorial - by InputUsername")

  for i = 1, #tMainOptions do -- starts a for loop to print all the options in the table 'tMainOptions'
		term.setCursorPos(2,1 + (i * 2)) -- makes the cursor skip a line every time it prints an option
		term.write(tMainOptions[i]) -- prints the menu options as a 'button'
  end

end

local function drawGame() -- defines the drawGame function, which draws the contents of the 'game'

  term.clear()

  term.setCursorPos(2,1)
  term.write("Game!")

  term.setCursorPos(2,3)
  term.write("[ Back ]")
end

local function drawInfo() -- defines the drawInfo function, which is similar to the function 'drawMain()'

  term.clear()

  term.setCursorPos(2,1)
  term.write("Info")

  for i = 1, #tInfoOptions do
		term.setCursorPos(2,1 + (i * 2))
		term.write(tInfoOptions[i])
  end

end

local function drawCredits() -- defines the drawCredits function

  term.clear()

  term.setCursorPos(2,1)
  term.write("Credits")

  term.setCursorPos(2,2)
  term.write("Mouse menu tutorial, [c]2012 InputUsername")
end


--[[
Here we start the menu's functionality
]]--
while true do -- start an infinite loop

  if state == "main" then -- if the current menu is the main menu
		drawMain() -- calls the drawMain() function, which draws the main menu

		local event, button, X, Y = os.pullEvent("mouse_click") -- waits for a mouse click

		if button == 1 then -- if the user clicks with the left button (1 is left, 2 is right)
		  for i = 1, #tMainOptions do -- some 'complicated' code to check where the mouse click was
				if X >= 2 and X <= #(tMainOptions[i]) + 2 and Y == 1 + (i * 2) then
				  if i == 1 then
						state = "play"
				  elseif i == 2 then
					state = "info"
				  elseif i == 3 then
					state = "exit"
				  end
				end
		  end
		end

  elseif state == "play" then
	drawGame() -- draws the contents of the 'game'

		local event, button, X, Y = os.pullEvent("mouse_click") -- waits for a mouse click

		if button == 1 then
		  if X >= 2  and X <= 6 and Y == 3 then
				state = "main"
		  end
		end
  elseif state == "info" then
	drawInfo()

		local event, button, X, Y = os.pullEvent("mouse_click") -- waits for a mouse click

		if button == 1 then
		  for i = 1, #tInfoOptions do
				if X >= 2 and X <= #(tMainOptions[i]) + 2 and Y == 1 + (i * 2) then
				  if i == 1 then
						state = "credits"
				  elseif i == 2 then
						state = "main"
				  end
				end
		  end
		end

  elseif state == "credits" then
	drawCredits() -- draw the credits

		sleep(2) -- wait 2 seconds

		state = "main" -- return to the main menu
  elseif state == "exit" then
	break
  end

end

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