calc.lua
require("keys")
require("logger")
calc = {}
calc.value = ""
calc.buttons =
{
{"log", "exp", "pi", "(",")","^","/"},
{"sin", "cos", "tan", "7","8","9","*"},
{"asin","acos", "atan","4","5","6","-"},
{"abs", "floor","ceil","1","2","3","+"},
{"sqrt","%", ",", "0",".","C","="}
}
calc.row = 5
calc.col = 4
calc.rows = #(calc.buttons)
calc.cols = #(calc.buttons[1])
calc.font = FONT.LARGE
calc.border = COLOR.gray(75)
calc.background = COLOR.gray(5)
calc.foreground = COLOR.WHITE
calc.highlight = COLOR.BLUE
calc.error_forground = COLOR.RED
calc.pad = 20
calc.cell_size = calc.pad * 2 + calc.font.height
calc.height = (calc.rows + 1) * calc.cell_size
calc.width = (calc.cols) * calc.cell_size
calc.left = display.width // 2 - calc.width // 2
calc.top = display.height // 2 - calc.height // 2
calc.error = false
calc.mlmenu = menu.new
{
name = "Calculator",
help = "A simple calculator in Lua",
select = function(this)
task.create(function() calc:run() end)
end,
update = function(this) return calc.value end
}
function calc:run()
local status, error = xpcall(function()
menu.block(true)
self:main_loop()
end, debug.traceback)
if status == false then
handle_error(error)
end
menu.block(false)
keys:stop()
end
function calc:main_loop()
menu.block(true)
self:draw()
keys:start()
while true do
if menu.visible == false then break end
local key = keys:getkey()
if key ~= nil then
if self:handle_key(key) == false then
break
end
self:draw()
end
task.yield(100)
end
keys:stop()
if self.running == false then menu.block(false) end
end
function calc:handle_key(key)
if key == KEY.Q or key == KEY.MENU then return false
elseif key == KEY.UP or key == KEY.WHEEL_UP then
self.row = dec(self.row,1,self.rows)
elseif key == KEY.DOWN or key == KEY.WHEEL_DOWN then
self.row = inc(self.row,1,self.rows)
elseif key == KEY.LEFT or key == KEY.WHEEL_LEFT then
self.col = dec(self.col,1,self.cols)
elseif key == KEY.RIGHT or key == KEY.WHEEL_RIGHT then
self.col = inc(self.col,1,self.cols)
elseif key == KEY.INFO then
self:handle_button("C")
elseif key == KEY.PLAY then
self:handle_button("=")
elseif key == KEY.SET then
self:handle_button(self.buttons[self.row][self.col])
end
end
function calc:handle_button(c)
if self.error or type(self.value) ~= "string" then
self.value = ""
end
self.error = false
if c == "C" then
self.value = ""
elseif c == "=" then
local status,result = pcall(load,"return "..self.value)
if status == false or result == nil then
self.error = true
self.value = "syntax error"
else
status,self.value = pcall(result)
if self.status == false or self.value == nil then
self.error = true
self.value = "syntax error"
else
self.value = tostring(self.value)
end
end
else
self.value = self.value..c
if #c > 2 then
self.value = self.value.."("
end
end
end
function calc:draw()
display.draw(function()
display.rect(self.left-4,self.top-4,self.width+8,self.height+8,self.border,self.border)
display.rect(self.left,self.top,self.width,self.cell_size,self.border,self.background)
local fg = self.foreground
if self.error then fg = self.error_forground end
display.print(tostring(self.value),self.left + self.pad,self.top + self.pad,self.font,fg,self.background, self.width - self.pad * 2)
for i=1,self.rows,1 do
local row = self.buttons[i]
for j=1,self.cols,1 do
local c = row[j]
local x = self.left + (j - 1) * self.cell_size
local y = self.top + i * self.cell_size
local bg = self.background
if i == self.row and j == self.col then bg = self.highlight end
display.rect(x,y,self.cell_size,self.cell_size,self.border,bg)
local pad = self.cell_size // 2 - self.font:width(c) // 2
display.print(c,x + pad, y + self.pad,self.font,self.border,bg)
end
end
end)
end
for k,v in pairs(math) do
if k ~= "type" then
_G[k] = v
end
end
function inc(val,min,max)
if val == max then return min end
if val < min then return min end
return val + 1
end
function dec(val,min,max)
if val == min then return max end
if val > max then return max end
return val - 1
end
function handle_error(error)
if error == nil then error = "Unknown Error!\n" end
local f = FONT.MONO_20
display.rect(0,0,display.width,display.height,COLOR.RED,COLOR.BLACK)
local pos = 10
for line in error:gmatch("[^\r\n]+") do
local clipped = display.print(line,10,pos,f)
while clipped ~= nil do
pos = pos + f.height
clipped = display.print(clipped,10,pos,f)
end
pos = pos + f.height
end
local log = logger("CALC.ERR")
log:write(error)
log:close()
keys:anykey()
end