-- TIME_STAMP   2013-10-28 10:07:54

local vcl = require "vcl"

-- Objekt Rechner
local oCalc = {
	operation = '',
	firstVal  = 0,
	secondVal = 0,
	add       = function(self) return (self.firstVal + self.secondVal) end,
	sub       = function(self) return (self.firstVal - self.secondVal) end,
	mul       = function(self) return (self.firstVal * self.secondVal) end,
	div       = function(self) local res if self.secondVal == 0 then res = '' else res = (self.firstVal / self.secondVal) end return res end,
	valid     = function(self) if not tonumber(self.firstVal) or not tonumber(self.secondVal) then return 'Error - no value' end end
}

-- Objekt Button Class
local buttonDefault = {
	caption   = '',
	name      = '',
	id        = nil,
	done      = false,
	SetFocus  = function(self) self.id:SetFocus() end,
	Free      = function(self) self.id:Free() end,
	SetButton = function(self, _form, _caption, ...)
					self.id = vcl.Button(_form)
					self.id._ = {left = 0, top = 0, width = 30, height = 30, caption = _caption}
					self.id.OnClick = "ClickButton"
					self.caption = _caption
					self.name = self.id.name
					if arg then
						local tArg = arg[1]
						self.id._ = tArg
					end
				end,
	New       = function(self, obj)
					obj = obj or {}
					setmetatable(obj, self)
					self.__index = self
					return obj
				end
}

-- GUI erstellen
mainForm       = vcl.Form("mainForm")
mainForm._     = { caption = "Rechner", position="poDesktopCenter", height=235, width=155, cursor="crHourGlass", color = 0xFFF8F0 }
mainForm.Image = "C:/Users/BugFix/Pictures/ICON/Icons-ico/Computer/Windows 95 - Arbeitsplatz.ico"

-- Label für Anzeige erstellen
local label1 = vcl.Label(mainForm)
local label2 = vcl.Label(mainForm)
label1._ = {autoSize=false, alignment='taRightJustify', layout='tlCenter', caption='', left=10, top=10, height=20, width=135, color=0xE0FFFF}
label2._ = {autoSize=false, alignment='taRightJustify', layout='tlCenter', caption='', left=10, top=30, height=20, width=135, color=0xE0FFEE}

-- Digit-Button erstellen, named index "d0...d9"
local iLeft, iTop, tBtn, index = 10, 55, {}
for i = 9,0,-1 do
	if i % 3 == 0 then iLeft = 80 iTop = iTop +35 end
	index = tostring('d'..i)
	tBtn[index] = buttonDefault:New()
	tBtn[index]:SetButton(mainForm, tostring(i), {left=iLeft, top=iTop})
	iLeft = iLeft - 35
end
tBtn.d0.id._ = {width = 65, left = 10}
tBtn.dot = buttonDefault:New()
tBtn.dot:SetButton(mainForm, ',', {left=iLeft+35, top=iTop})

-- Operation-Button erstellen
iLeft = 10 iTop = 55
local tOps = {{'back','back',0,0},{'div','/',35,0},{'mul','x',70,0},{'clear','C',105,0},{'sub','-',105,35},{'add','+',105,70},{'calc','=',105,105}}
for i = 1,#tOps do
	tBtn[tOps[i][1] ] = buttonDefault:New()
	tBtn[tOps[i][1] ]:SetButton(mainForm, tOps[i][2], {left=iLeft+tOps[i][3], top=iTop+tOps[i][4]})
end
tBtn.calc.id.height = 65

-- Event-Funktionen
function ClickButton(Sender)
	local set = function(_l, _v) _l.caption = _v _l:Refresh() end
	local get = function(_l) return _l.caption end
	local s = Sender.caption
	local g
	if ('0123456789'):find(s) then
		if oCalc.done then set(label2, '') oCalc.done = false end
		set(label2, get(label2)..s)
	elseif ('%+%-x/'):find(s) then
		oCalc.operation = s
		oCalc.firstVal = get(label2)
		if oCalc.done then
			oCalc.done = false
			set(label1, get(label1)..' '..s)
		else
			set(label1, get(label2)..' '..s)
		end
		set(label2, '')
	elseif s == ',' then
		set(label2, get(label2)..'.')
	elseif s == 'back' then
		g = get(label2)
		if g == '' then return end
		set(label2, g:sub(1, #g-1))
	elseif s == 'C' then
		set(label2, '')
	elseif s == '=' then
		local op = oCalc.operation
		set(label1, get(label1)..' '..get(label2))
		oCalc.secondVal = get(label2)
		if op == '+' then
			set(label2, oCalc:add() )
		elseif op == '-' then
			set(label2, oCalc:sub() )
		elseif op == 'x' then
			set(label2, oCalc:mul() )
		elseif op == '/' then
			set(label2, oCalc:div() )
		end
		oCalc.done = true
	end
end

function onCloseQueryEventHandler(Sender)
	return true
end

-- GUI anzeigen
mainForm:ShowModal()

-- Speicher freigeben
mainForm:Free()