Button API

local tButtons = {}

function clear()
  tButtons = {}
end

function new(_sText, _nX, _nY, _nWidth, _nHeight, _nTextColour, _nOffColour, _nOnColour, _fClick, _nDelay)
  if type(_sText) ~= "string" then
    error("Argument 1: string expected, got "..type(text), 2)
  elseif type(_nX) ~= "number" then
    error("Argument 2: number expected, got "..type(_nX), 2)
  elseif type(_nY) ~= "number" then
    error("Argument 3: number expected, got "..type(_nY), 2)
  elseif type(_nWidth) ~= "number" then
    error("Argument 4: number expected, got "..type(_nWidth), 2)
  elseif type(_nHeight) ~= "number" then
    error("Argument 5: number expected, got "..type(_nHeight), 2)
  elseif type(_fClick) ~= "function"  then
    error("Argument 8: function expected, got "..type(_fClick), 2)
  elseif type(_nDelay) ~= "number" then
    error("Argument 9: number expected, got "..type(_nDelay), 2)
  end
  table.insert(tButtons, {
    text = _sText,
    x = math.floor(_nX),
    endX = math.floor((_nX + _nWidth) - 1),
    y = _nY,
    endY = math.floor((_nY + _nHeight) - 1),
    w = math.floor(_nWidth),
    h = math.floor(_nHeight),
    textCol = _nTextColour,
    onCol = _nOnColour,
    offCol = _nOffColour,
    on_click = _fClick,
    delay = _nDelay,
    value = false
  })
end

local function draw(bText, x, y)
  local col
  for _, v in pairs(tButtons) do
    if bText == v.text and x == v.x and y == v.y then
      if v.value then
        col = v.onCol
      else
        col = v.offCol
      end
      for y = v.y, v.endY do
        paintutils.drawLine(v.x, y, v.endX, y, col)
      end
      term.setTextColour(v.textCol)
      term.setCursorPos(((v.endX + v.x - #v.text) / 2) + 1, (v.endY + v.y) / 2)
      term.write(v.text)
    end
  end
end

function run()
  for _, v in pairs(tButtons) do
    draw(v.text, v.x, v.y, v.uID)
  end
  while true do
    local _, p1, x, y = os.pullEvent("monitor_touch")
    for _, v in pairs(tButtons) do
      if (x >= v.x and x <= v.endX and y >= v.y and y <= v.endY) then
        parallel.waitForAll(
          function()
            v.value = true
            draw(v.text, v.x, v.y)
            sleep(v.delay)
            v.value = false
            draw(v.text, v.x, v.y)
          end,
          v.on_click
        )
      end
    end
  end
end