notepad-memos

-- Memos app by Miki_Tellurium
-- Version: 1.0.0

local library = require("button")

local memos = {}
local linesScrolled = 0
local defaultBackgroundColor = colors.black
local defaultTextColor = colors.white
term.setCursorBlink(false)
term.setPaletteColor(colors.yellow, 0xFFFF00)

local exit = button:new()
exit:setLabel("Exit")
exit:setBackgroundColor(colors.red)
exit:setTextColor(colors.black)
exit:setLocation(10, 1)

--Check if notes file already exist
local function doNotesExist()
 local notes = io.open("notes.txt", "r")

 if notes ~= nil then
  io.close(notes)
  return true
 else
  return false
 end
end

--If file exist read it, else create it
local function loadMemos()
 memos = {}
 if doNotesExist() then
  local notes = io.open("notes.txt", "r")
  for line in io.lines("notes.txt") do
   table.insert(memos, line)
  end
  io.close(notes)
 else
  local notes = io.open("notes.txt", "w")
  io.close(notes)
 end
end
--Update notes.txt with new written memos
local function updateMemos()
 local notes = io.open("notes.txt", "w")
 for key,line in pairs(memos) do
  io.output(notes)
  io.write(line.."\n")
 end
 io.close(notes)
end

--Write memos on screen
local function showMemos()
 local lineUsed = 0
 term.clear()
 term.setCursorPos(1, 1)
 term.setTextColor(colors.yellow)
 print("Memos:")
 exit:paint()
 print()
 term.setTextColor(defaultTextColor)
 for key,text in pairs(memos) do
  if lineUsed > 16 then
   break
  end
  term.clearLine()
  print("-"..text)
  if #text > 25 then
   lineUsed = lineUsed + math.ceil(#text/25)
  else
   lineUsed = lineUsed + 1
  end
 end
 term.setCursorPos(1, 20)
 term.setTextColor(colors.lightBlue)
 term.write("Up/down arrow to scroll")
end
--Draw buttons on screen
local function makeButtons()
 add = button:new()
 remove = button:new()

 add:setLabel("Add")
 add:setBackgroundColor(colors.green)
 add:setTextColor(colors.white)
 add:setLocation(18, 1)
 remove:setLabel("Remove")
 remove:setBackgroundColor(colors.red)
 remove:setTextColor(colors.white)
 remove:setLocation(21, 1)

 add:paint()
 remove:paint()
end
--Function used to add memos
local function addMemos()
 term.setTextColor(defaultBackgroundColor)
 term.setTextColor(defaultTextColor)
 term.clear()
 term.setCursorPos(1, 1)
 print("Write a new memo:")
 write(">")

 --Read text and add memo
 local function addMemo()
  text = read()
  if text == "" then --TODO: add empty text check
   return
  end
  local notes = io.open("notes.txt", "a")
  io.output(notes)
  io.write(text, "\n")
  io.close(notes)
  table.insert(memos, text)
  linesScrolled = 0
 end

 --Cancel and return to main screen
 local function exit()
  cancel = button:new()
  cancel:setTextColor(colors.black)
  cancel:setBackgroundColor(colors.red)
  cancel:setLocation(26, 1)
  cancel:setLabel("X")
  cancel:paint()
  while true do
   local event = {os.pullEvent("mouse_click")}
   if cancel:waitForClick(event) then
    linesScrolled = 0
    return
   end
  end
 end

 parallel.waitForAny(addMemo, exit)
 term.setCursorBlink(false)
end

--Remove memos function
local function removeMemos()
 local xButtons = {}
 local memosScrolled = 0
 local line = 3
 term.setBackgroundColor(defaultBackgroundColor)
 term.setTextColor(defaultTextColor)
 cancel = button:new()
 cancel:setTextColor(colors.black)
 cancel:setBackgroundColor(colors.red)
 cancel:setLocation(26, 1)
 cancel:setLabel("X")
 for b = 1,8 do
  b = button:new()
  b:setLabel("x")
  b:setLocation(1, line)
  b:setBackgroundColor(colors.red)
  b:setTextColor(colors.black)
  table.insert(xButtons, b)
 end
 local function drawDeleteScreen()
  local line = 3
  term.clear()
  term.setCursorPos(1, 1)
  print("Choose a memo to delete:")
  cancel:paint()
  print()
  for key,text in pairs(memos) do
   if key > 8 then
    break
   end
   xButtons[key]:setLocation(1, line)
   xButtons[key]:paint()
   term.setCursorPos(2, line)
   print(text)
   print()
   line = line + 2
  end
  term.setCursorPos(1, 20)
  term.setTextColor(colors.lightBlue)
  term.write("Up/down arrow to scroll")
  term.setTextColor(colors.white)
 end
 --Make the screen scroll
 local function scrollDelete(key)
 if key == 265 then  --Scroll up
   memosScrolled = memosScrolled - 1
   if memosScrolled < 0 then
    memosScrolled = 0
   end
   for i = 1,memosScrolled do
    table.remove(memos, 1)
   end
  elseif key == 264 then --Scroll down
   memosScrolled = memosScrolled + 1
   if memosScrolled > #memos - 8 then
    memosScrolled = #memos - 8
   end
   for i = 1,memosScrolled do
    table.remove(memos, 1)
   end
  end
 end

 drawDeleteScreen()
 while true do
  local event = {os.pullEvent()}
  for key,button in pairs(xButtons) do
   --Remove the memo that was clicked
   if button:waitForClick(event) then
    term.clear()
    term.setCursorPos(1, 1)
    term.setTextColor(colors.orange)
    print("Deleted memo:")
    term.setTextColor(colors.white)
    print(memos[key + memosScrolled])
    table.remove(memos, key + memosScrolled)
    sleep(1.15)
    updateMemos()
    return
   --Cancel and beck to main screen
   elseif cancel:waitForClick(event) then
    return
   end
  end
  --Scroll function
  if event[1] == "key" then
   scrollDelete(event[2])
   drawDeleteScreen()
   loadMemos()
  end
 end
end
--265 up arrow, 264 down arrow
local function scroll(key)
 if key == 265 then  --Scroll up
  linesScrolled = linesScrolled - 1
  if linesScrolled < 0 then
   linesScrolled = 0
  end
  for i = 1,linesScrolled do
   table.remove(memos, 1)
  end
  showMemos()
  loadMemos()
 elseif key == 264 then --Scroll down
  linesScrolled = linesScrolled + 1
  if linesScrolled > #memos - 17 then
   linesScrolled = #memos - 17
  end
  for i = 1,linesScrolled do
   table.remove(memos, 1)
  end
  showMemos()
  loadMemos()
 end
end
--Perform different actions based on button pressed
local function buttonAction()
  local event = {os.pullEvent()}
 if add:waitForClick(event) then
  addMemos()
  showMemos()
 elseif remove:waitForClick(event) then
  removeMemos()
  showMemos()
 elseif event[1] == "key" then
  scroll(event[2])
 elseif exit:waitForClick(event) then
  os.reboot()
 end
end

--Run program
loadMemos()
term.clear()
showMemos()
while true do
 makeButtons()
 buttonAction()
end