Calculator

local Total, Memory, Operando = 0, 0, ""

function Gui()
    term.setBackgroundColor(colors.black)
    term.clear()

    if (Memory ~= 0) then
        term.setCursorPos(1,1)
        term.write(Memory)
    end
    term.setCursorPos(1,2)
    term.write(Operando)
    term.setCursorPos(1,3)
    term.write(Total)

    --remove when done
    paintutils.drawLine(27,1,27,20,colors.white)

    --Number buttons
    paintutils.drawFilledBox(1,4,5,7,colors.yellow)
    term.setCursorPos(3,6)
    term.write("7")
    paintutils.drawFilledBox(6,4,10,7,colors.orange)
    term.setCursorPos(8,6)
    term.write("8")
    paintutils.drawFilledBox(11,4,15,7,colors.yellow)
    term.setCursorPos(13,6)
    term.write("9")
    paintutils.drawFilledBox(1,8,5,11,colors.orange)
    term.setCursorPos(3,10)
    term.write("4")
    paintutils.drawFilledBox(6,8,10,11,colors.yellow)
    term.setCursorPos(8,10)
    term.write("5")
    paintutils.drawFilledBox(11,8,15,11,colors.orange)
    term.setCursorPos(13,10)
    term.write("6")
    paintutils.drawFilledBox(1,12,5,15,colors.yellow)
    term.setCursorPos(3,14)
    term.write("1")
    paintutils.drawFilledBox(6,12,10,15,colors.orange)
    term.setCursorPos(8,14)
    term.write("2")
    paintutils.drawFilledBox(11,12,15,15,colors.yellow)
    term.setCursorPos(13,14)
    term.write("3")
    paintutils.drawFilledBox(1,16,5,19,colors.orange)
    term.setCursorPos(3,18)
    term.write("")
    paintutils.drawFilledBox(6,16,10,19,colors.yellow)
    term.setCursorPos(8,18)
    term.write("0")
    paintutils.drawFilledBox(11,16,15,19,colors.orange)
    term.setCursorPos(13,18)
    term.write(",")

    --Operators Buttons
    paintutils.drawFilledBox(16,4,20,7,colors.gray)
    term.setCursorPos(18,6)
    term.write("/")
    paintutils.drawFilledBox(21,4,26,7,colors.lightGray)
    term.setCursorPos(23,6)
    term.write("<<")
    paintutils.drawFilledBox(16,8,20,11,colors.lightGray)
    term.setCursorPos(18,10)
    term.write("*")
    paintutils.drawFilledBox(21,8,26,11,colors.gray)
    term.setCursorPos(23,10)
    term.write("CE")
    paintutils.drawFilledBox(16,12,20,15,colors.gray)
    term.setCursorPos(18,14)
    term.write("-")
    paintutils.drawFilledBox(21,12,26,15,colors.lightGray)
    term.setCursorPos(23,14)
    term.write("+")
    paintutils.drawFilledBox(16,16,20,19,colors.lightGray)
    term.setCursorPos(18,18)
    term.write("%")
    paintutils.drawFilledBox(21,16,26,19,colors.gray)
    term.setCursorPos(23,18)
    term.write("=")
end

function KeyPress(key)
    key = keys.getName(key)

    if (key == "+") then
        operando = "+"
    elseif (key == "-") then
        operando = "-"
    elseif (key == "*") then
        operando = "*"
    elseif (key == "/") then
        operando = "/"
    else
        if (key == "zero") then key = "0"
        elseif (key == "one") then key = "1"
        elseif (key == "two") then key = "2"
        elseif (key == "three") then key = "3"
        elseif (key == "four") then key = "4"
        elseif (key == "five") then key = "5"
        elseif (key == "six") then key = "6"
        elseif (key == "seven") then key = "7"
        elseif (key == "eight") then key = "8"
        elseif (key == "nine") then key = "9"
        end

        if (Operando == "") then
            if (Total == 0) then
                Total = tonumber(key)
            else
                Total = Total .. tonumber(key)
            end
        elseif (Operando == "+") then
            Total = Total + tonumber(key)
        elseif (Operando == "-") then
            Total = Total - tonumber(key)
        elseif (Operando == "*") then
            Total = Total * tonumber(key)
        elseif (Operando == "/") then
            Total = Total / tonumber(key)
        end
    end
end

function Click(x,y)
    -- Numbers
    if (x>=1 and x<=5 and y>=4 and y<=7) then
        if (Total == 0) then
            Total = 7
        else
            Total = Total .. 7
        end
    elseif (x>=6 and x<=10 and y>=4 and y<=7) then
        if (Total == 0) then
            Total = 8
        else
            Total = Total .. 8
        end
    elseif (x>=11 and x<=15 and y>=4 and y<=7) then
        if (Total == 0) then
            Total = 9
        else
            Total = Total .. 9
        end
    elseif (x>=1 and x<=5 and y>=8 and y<=11) then
        if (Total == 0) then
            Total = 4
        else
            Total = Total .. 4
        end
    elseif (x>=6 and x<=10 and y>=8 and y<=11) then
        if (Total == 0) then
            Total = 5
        else
            Total = Total .. 5
        end
    elseif (x>=11 and x<=15 and y>=8 and y<=11) then
        if (Total == 0) then
            Total = 6
        else
            Total = Total .. 6
        end
    elseif (x>=1 and x<=5 and y>=12 and y<=15) then
        if (Total == 0) then
            Total = 1
        else
            Total = Total .. 1
        end
    elseif (x>=6 and x<=10 and y>=12 and y<=15) then
        if (Total == 0) then
            Total = 2
        else
            Total = Total .. 2
        end
    elseif (x>=11 and x<=15 and y>=12 and y<=15) then
        if (Total == 0) then
            Total = 3
        else
            Total = Total .. 3
        end
    elseif (x>=6 and x<=10 and y>=16 and y<=19) then
        if (Total == 0) then
            Total = 0
        else
            Total = Total .. 0
        end
    end

    --Symbols
    if (x>=16 and x<=20 and y>=4 and y<=7) then
        Memory = Total
        Total = 0
        Operando = "/"
    elseif (x>=21 and x<=26 and y>=4 and y<=7) then
        local sTotal = tostring(Total)
        Total = tonumber(string.sub(sTotal,1,string.len(sTotal)-1))
        if (Total == nil) then
            Total=0
        end
    elseif (x>=16 and x<=20 and y>=8 and y<=11) then
        Memory = Total
        Total = 0
        Operando = "*"
    elseif (x>=21 and x<=26 and y>=8 and y<=11) then
        Memory = 0
        Total = 0
        Operando = ""
    elseif (x>=16 and x<=20 and y>=12 and y<=15) then
        Memory = Total
        Total = 0
        Operando = "-"
    elseif (x>=21 and x<=26 and y>=12 and y<=15) then
        Memory = Total
        Total = 0
        Operando = "+"
    elseif (x>=16 and x<=20 and y>=16 and y<=19) then
        Memory = Total
        Total = 0
        Operando = "%"
    elseif (x>=21 and x<=26 and y>=16 and y<=19) then
        if (Operando == "+") then
            Total = Memory + Total
            Memory = 0
            Operando = ""
        elseif (Operando == "-") then
            Total = Memory - Total
            Memory = 0
            Operando = ""
        elseif (Operando == "*") then
            Total = Memory * Total
            Memory = 0
            Operando = ""
        elseif (Operando == "/") then
            Total = Memory / Total
            Memory = 0
            Operando = ""
        elseif (Operando == "%") then
            Total = Memory % Total
            Memory = 0
            Operando = ""
        end
    end
end

-- Main --
while (true) do
    Gui()
    term.setCursorPos(1,1)
    parallel.waitForAny(function()
            local event, key, is_held = os.pullEvent("key")
            --KeyPress(key)
        end,
        function()
            local event, button, x, y = os.pullEvent("mouse_click")
            Click(x,y)
        end)
end