Multi-Monitor-Buttons

monitors = {peripheral.find("monitor")}
local allMon = {}
for funcName,_ in pairs(monitors[1]) do
    allMon[funcName] = function(...)
        for i=1,#monitors-1 do monitors[i][funcName](unpack(arg)) end
        return monitors[#monitors][funcName](unpack(arg))
    end
end

local sides = {"left", "right", "front", "back", "bottom", "top"}
local monitor = {}

for a,b in pairs(sides) do
    local monObject = peripheral.wrap(b)
    if monObject then
        monitor[b] = monObject
    end
end

allMon.setTextScale(1)
allMon.setTextColor(colors.white)
allMon.setBackgroundColor(colors.black)

local button={}

function clearAll()
   button = {}
end

function clearTable(name)
    button[name] = {}
end

function getPlayer(name)
    return button[name]["player"]
end

function setPlayer(name, player)
    button[name]["player"] = player
    screen()
end

function getState(name)
    return button[name]["active"]
end

function setState(name, state)
    button[name]["active"] = state
    screen()
end

-- monSide: "left", "right", "front", "back", "bottom", "top"
function setTable(name, func, param, xmin, xmax, ymin, ymax, monSide)
    button[name] = {}
    button[name]["func"] = func
    button[name]["active"] = false
    button[name]["player"] = "empty"
    button[name]["param"] = param
    button[name]["xmin"] = xmin
    button[name]["ymin"] = ymin
    button[name]["xmax"] = xmax
    button[name]["ymax"] = ymax
    if not monitor[monSide] then
        print("There is no monitor on the "..monSide.." side! The button named \""..name.."\" won't be displayed.")
        button[name]["mon"] = nil
    else
        button[name]["mon"] = monSide
    end
end

-- returns true if there is a monitor connected at the given side
function testForMonitor(monSide)
    if not monSide then
        return false
    end
    if not monitors[monSide] then
        return false
    end
    return true
end


function fill(text, color, bData)
    if not testForMonitor(bData["mon"]) then
        return
    end
    local display = monitors[bData["mon"]]
    display.setBackgroundColor(color)
    local on = bData["player"]
    local xSize = bData["xmax"] - bData["xmin"]
    local ySize = bData["ymax"] - bData["ymin"]
    local sizeRel = xSize / ySize
    for j = bData["ymin"], bData["ymax"] do -- draws a rectangle
        display.setCursorPos(bData["xmin"], j)
        for i = bData["xmin"], bData["xmax"] do
            display.write(" ")
        end
    end
    if on == "x" then -- draws a cross on top
        local xOffset = 0
        local scaledYOffset = 0
        display.setBackgroundColor(colors.red)
        for j = bData["ymin"], bData["ymax"] do
            scaledYOffset = (j - bData["ymin"]) * sizeRel
            for i = bData["xmin"], bData["xmax"] do
                xOffset = i - bData["xmin"]
                if (math.floor(math.abs(xOffset - scaledYOffset)-2.2) < 0) or (math.floor(math.abs(xOffset + scaledYOffset - xSize)-2.2) < 0) then
                    display.setCursorPos(i, j)
                    display.write(" ")
                end
            end
        end
    elseif on == "o" then -- draws a circle on top
        local xOffset = 0
        local scaledYOffset = 0
        local halfSize = xSize / 2
        display.setBackgroundColor(colors.red)
        for j = bData["ymin"], bData["ymax"] do
            scaledYOffset = math.abs(halfSize - ((j - bData["ymin"]) * sizeRel))
            for i = bData["xmin"], bData["xmax"] do
                xOffset = math.abs(halfSize - (i - bData["xmin"]))
                if math.floor(math.abs(math.sqrt(scaledYOffset^2+xOffset^2) - halfSize)-1.9) < 0 then
                    display.setCursorPos(i, j)
                    display.write(" ")
                end
            end
        end
    end
    display.setBackgroundColor(colors.black)
end

function screen()
    local currColor
    local currDisplayName
    for name,data in pairs(button) do
        local on = data["player"]
        if on == "empty" then
            currDisplayName = " "
        elseif on == "x" then
            currDisplayName = on
        elseif on == "o" then
            currDisplayName = on
        end
        if data["active"] then
            currColor = colors.lime
        else
            if on == "empty" then
                currColor = colors.white
            elseif on == "x" then
                currColor = colors.lightGray
            elseif on == "o" then
                currColor = colors.lightGray
            end
        end
        fill(currDisplayName, currColor, data)
    end
end

function toggleButton(name)
    button[name]["active"] = not button[name]["active"]
    screen()
end

function flash(name)
    toggleButton(name)
    screen()
    sleep(0.15)
    toggleButton(name)
    screen()
end

function checkxy(x, y, side)
    for name, data in pairs(button) do
        if data["mon"] == side then
            if y>=data["ymin"] and  y <= data["ymax"] then
                if x>=data["xmin"] and x<= data["xmax"] then
                    if data["param"] == "" then
                        data["func"]()
                    else
                        data["func"](data["param"])
                    end
                    return true
                    --data["active"] = not data["active"]
                    --print(name)
                end
            end
        end
    end
    return false
end

function heading(text, monSide)
    if not testForMonitor(monSide) then
        print("Heading cannot be displayed on "..monSide..".")
        return
    end
    local display = monitors[bData["mon"]]
    w, h = display.getSize()
    display.setCursorPos((w-string.len(text))/2+1, 1)
    display.write(text)
end

function label(w, h, text, monSide)
    if not testForMonitor(monSide) then
        print("Heading cannot be displayed on "..monSide..".")
        return
    end
    local display = monitors[bData["mon"]]
    display.setCursorPos(w, h)
    display.write(text)
end