calculator.js

var rotateLeft = "\u2939"
var rotateRight = "\u2935"
var leftArrow = "\u2190"
var division = "\u00f7"
var multiplication = "\u00d7"
var squareRoot = "\u221a"
var plusminus = "\u00b1"


var curVal = 0
var memory = 0
var lastOp = ""
var timer = 0
var currentOperation = ""

 function disabled(op) {
     if (op == "." && calcwindow.displayText.toString().indexOf(".") != -1) {
         return true
     } else if (op == squareRoot &&  calcwindow.displayText.toString().search(/-/) != -1) {
         return true
     } else {
         return false
     }
 }

 function doOperation(op) {
     console.log("Called with " + op)
     if (disabled(op)) {
         return
     }

     if (op.toString().length==1 && ((op >= "0" && op <= "9") || op==".") ) {
         if (calcwindow.displayText.toString().length >= 14)
             return; // No arbitrary length numbers
         if (lastOp.toString().length == 1 &&
             ((lastOp >= "0" && lastOp <= "9") ||
              lastOp == ".") ||
              lastOp == leftArrow) {
             if (calcwindow.displayText == "0")
                 calcwindow.displayText = op.toString()
             else
                calcwindow.displayText = calcwindow.displayText + op.toString()
         } else {
             calcwindow.displayText = op
         }
         lastOp = op
         calcwindow.displayOperation = ""
         return
     }
     lastOp = op

     if (currentOperation == "+") {
         calcwindow.displayText = Number(calcwindow.displayText.valueOf()) + Number(curVal.valueOf())
     } else if (currentOperation == "-") {
         calcwindow.displayText = Number(curVal) - Number(calcwindow.displayText.valueOf())
     } else if (currentOperation == multiplication) {
         calcwindow.displayText = Number(curVal) * Number(calcwindow.displayText.valueOf())
     } else if (currentOperation == division) {
         calcwindow.displayText = Number(Number(curVal) /
                 Number(calcwindow.displayText.valueOf())).toString()
     } else if (currentOperation == "=") {
     }

     if (op == "+" || op == "-" || op == multiplication || op == division) {
         calcwindow.displayOperation = op
         currentOperation = op
         curVal = calcwindow.displayText.valueOf()
         return
     }

     currentOperation = ""
     calcwindow.displayOperation = ""

     curVal = 0

     if (op == "1/x") {
         calcwindow.displayText = (1 / calcwindow.displayText.valueOf()).toString()
     } else if (op == "x^2") {
         calcwindow.displayText = (calcwindow.displayText.valueOf() *
                 calcwindow.displayText.valueOf()).toString()
     } else if (op == "Abs") {
         calcwindow.displayText = (Math.abs(calcwindow.displayText.valueOf())).toString()
     } else if (op == "Int") {
         calcwindow.displayText = (Math.floor(calcwindow.displayText.valueOf())).toString()
     } else if (op == plusminus) {
         calcwindow.displayText = (calcwindow.displayText.valueOf() * -1).toString()
     } else if (op == squareRoot) {
         calcwindow.displayText = (Math.sqrt(calcwindow.displayText.valueOf())).toString()
     } else if (op == "mc") {
         memory = 0;
     } else if (op == "m+") {
         memory += calcwindow.displayText.valueOf()
     } else if (op == "mr") {
         calcwindow.displayText = memory.toString()
     } else if (op == "m-") {
         memory = calcwindow.displayText.valueOf()
     } else if (op == leftArrow) {
         calcwindow.displayText = calcwindow.displayText.toString().slice(0, -1)
         if (calcwindow.displayText.length == 0) {
             calcwindow.displayText = "0"
         }
     } else if (op == "Off") {
         Qt.quit();
     } else if (op == "C") {
         calcwindow.displayText = "0"
     } else if (op == "AC") {
         curVal = 0
         memory = 0
         lastOp = ""
         calcwindow.displayText ="0"
     }
 }