Gui creator

local oldPull = os.pullEvent
os.pullEvent = os.pullEventRaw

term.clear = function(c) if c then term.setBackgroundColor(c) end term.native.clear() term.setCursorPos(1,1) end
setColors = function(b,t) if b then term.setBackgroundColor(b) end if t then term.setTextColor(t) end end
clickedIn = function(mx,my,x,y,w,h) return (mx >= x and mx <= x + w and my >= y and my <= y + h) end
startsWith = function(str, prefix) prefix = tostring( prefix ) return str:sub( 1, prefix:len()) == prefix end

local localGui = {
  ["New button"] = { x = 1, y = 1, w = 5, h = 6, action = new },
  ["Generate Code"] = { x = 1, y = 1, w = 5, h = 6, action = generate },
  ["Cancel"] = { x = 1, y = 1, w = 5, h = 6, action = function() os.pullEvent = oldPull error() end },
}

local genericFuncs = [[local function checkButtonClicked(mouseX, mouseY)
  for _,v in pairs(buttons) do
    if mouseX >= v.x and mouseX <= v.x + v.w and mouseY >= v.y and mouseY <= v.y + v.h then
      v.action()
      return true
    end
  end
  return false
end

local function drawButtons()
  for k, v in pairs(buttons) do
    term.setBackgroundColor(v.bgColor)
    term.setTextColor(v.txtColor)
    for i = 0, v.h - 1 do
      term.setCursorPos(v.x,v.y+i)
      write(string.rep(" ", v.w))
    end
    term.setCursorPos(v.x,v.y)
    write(k)
  end
end

-- example main loop
while true do
  drawButtons()

  local event = { os.pullEvent() }

  if event[1] == "mouse_click" then
    if event[2] == 1 then -- left click
      checkButtonClicked(event[3]. event[4])
    end
  end
end
]]

local progButtons = {}
local progFuncs = {}

local function getInput(text, validationFunc, compareVal)
  local output
  while true do
    write(text)
    local input = read()
    local ok, val, err = validationFunc(input, compareVal)
    if ok then
      if err then
        if startsWith(err, "Error:") then
          term.setTextColor(colors.red)
        elseif startsWith(err, "Warning:") then
          term.setTextColor(colors.yellow)
        end
        print(err)
        term.setTextColor(colors.white)
        write("Continue Anyway? (y/n) ")
        local con = read()
        if con:lower() == "y" or con:lower() == "yes" then
          output = val
          break
        end
      else
        output = val
        break
      end
    else
      if startsWith(err, "Error:") then
        term.setTextColor(colors.red)
      elseif startsWith(err, "Warning:") then
        term.setTextColor(colors.yellow)
      end
      print(err)
      term.setTextColor(colors.white)
    end
  end
  return output
end

local function validateColor(icol, notused)
  local col = loadstring("return colors."..icol)
  col = col()
  if not col then
    return false, nil, "Error: "..icol.." is not a valid color."
  end
  return true, col, nil
end

local function new()
  local bText = getInput("Button Text: ", function(text)
    if progButtons[text] then
      return true, text, "Error: Button with that text already exists"
    end
    return true, text, nil
  end, nil)

  local bWidth = getInput("Button Width: ", function(num, text)
    local sw = term.getSize()
    num = tonumber(num)
    if not num then
      return false, nil, "Error: Not a number"
    else
      if num > sw then return true, num, "Warning: Button width is wider than current screens width" end
      if num < 0 then return false, nil, "Error: Button width cannot be less than 1" end
      if num < #text then return false, nil, "Error: Button width must be greater than text width" end
      return true, num, nil
    end
  end, bText)

  local bHeight = getInput("Button Height: ", function(num, notused)
    local sw,sh = term.getSize()
    num = tonumber(num)
    if not num then
      return false, nil, "Error: Not a number"
    else
      if num > sh then return true, num, "Warning: Button height is taller than current screens height" end
      if num < 0 then return false, nil, "Error: Button height cannot be less than 1" end
      return true, num, nil
    end
  end, nil)

  local bx = getInput("Button X: ", function(num, compare)
    local sw,sh = term.getSize()
    num = tonumber(num)
    if not num then
      return false, nil, "Error: Not a number"
    else
      if num > sw then return true, num, "Warning: Button X position would be off the current screens width" end
      if num + compare > sw then
        return true, num, "Warning: Button X position and width would make part of the button off the current screen"
      end
      return true, num, nil
    end
  end, bWidth)

  local by = getInput("Button Y: ", function(num, compare)
    local sw,sh = term.getSize()
    num = tonumber(num)
    if not num then
      return false, nil, "Error: Not a number"
    else
      if num > sh then return true, num, "Warning: Button Y position would be off the current screens height" end
      if num + compare > sh then
        return true, num, "Warning: Button Y position and height would make part of the button off the current screen"
      end
      return true, num, nil
    end
  end, bHeight)

  local bTextCol = getInput("Text Color (eg white, red, etc.): ", validateColor, nil)

  local bBgCol = getInput("Button Color (eg white, red, etc.): ", validateColor, nil)

  local bAction = getInput("Function name to call when button clicked:\n", function(text, notused) return true, text, nil end, nil) -- allow anything to be entered

  progButtons[bText] = { x = bx, y = by, w = bWidth, h = bHeight, txtColor = bTextCol, bgColor = bBgCol, action = bAction }
  progFuncs[#progFuncs+1] = bAction
end

local function generate( progname )
  local file = fs.open(progname,"w")
  file.write("local buttons = {\n")
  for text,buttoninfo in pairs(progButtons) do
    file.write("\t[\""..text.."\"] = {")
    for k,v in pairs(buttoninfo) do
      file.write(" "..k.." = "..v..",")
    end
    file.write("},\n")
  end
  file.write("}\n\n")

  for k,v in pairs(progFuncs) do
    if v ~= "error" and v ~= "os.shutdown" and v ~= "os.reboot" then
      file.write("local function "..v.."()\n\t\nend\n\n" )
    end
  end
  file.write(genericFuncs)
  file.close()
end

term.clear()
while true do
  new()
  write("File name: ")
  generate( read() )
  localGui.Cancel.action()
end