Test

mon = peripheral.find("monitor")
button = {}
mon.setTextScale(0.5)

function createButton(name, func, Xstart, Ystart, Xend, Yend)
    button[name] = {}
    button[name]["func"] = func
    button[name]["active"] = false
    button[name]["Xstart"] = Xstart
    button[name]["Xend"] = Xend
    button[name]["Ystart"] = Ystart
    button[name]["Yend"] = Yend
end

function fill(text, color, bName)
mon.setBackgroundColor(color)
data = button[bName]
local yspot = math.floor((data["Ystart"] + data["Yend"])/2)
local xspot = math.floor((data["Xend"]-data["Xstart"]-#text)/2)+1
for j = data["Ystart"],data["Yend"] do
mon.setCursorPos(Xpos, j)
if j == yspot then
k = 0
while k <= data["Xend"] do
if k == xspot then
mon.write(text)
k = k + #text
else
mon.write(" ")
k = k + 1
end
end
else
for i = data["Xstart"], data["Xend"] do
mon.write(" ")
end
end
end
mon.setBackgroundColor(colors.black)
end

createButton("lul", test, 5,5,30,10)
fill("Balloe", colors.pink, "lul")