- Qt 5.5
- Qt Quick
- Qt Quick Demo - Calqlatr
- calculator.js Example File
- Qt 5.5.1 Reference Documentation

# calculator.js Example File

demos/calqlatr/content/calculator.js

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
    ** met:
    **   * Redistributions of source code must retain the above copyright
    **     notice, this list of conditions and the following disclaimer.
    **   * Redistributions in binary form must reproduce the above copyright
    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
    **   * Neither the name of The Qt Company Ltd nor the names of its
    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
    **
    **
    ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
    **
    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    var curVal = 0
    var memory = 0
    var lastOp = ""
    var previousOperator = ""
    var digits = ""

    function disabled(op) {
        if (digits == "" && !((op >= "0" && op <= "9") || op == "."))
            return true
        else if (op == '=' && previousOperator.length != 1)
            return true
        else if (op == "." && digits.toString().search(/\./) != -1) {
            return true
        } else if (op == "√" &&  digits.toString().search(/-/) != -1) {
            return true
        } else {
            return false
        }
    }

    function digitPressed(op)
    {
        if (disabled(op))
            return
        if (digits.toString().length >= display.maxDigits)
            return
        if (lastOp.toString().length == 1 && ((lastOp >= "0" && lastOp <= "9") || lastOp == ".") ) {
            digits = digits + op.toString()
            display.appendDigit(op.toString())
        } else {
            digits = op
            display.appendDigit(op.toString())
        }
        lastOp = op
    }

    function operatorPressed(op)
    {
        if (disabled(op))
            return
        lastOp = op

        if (op == "±") {
                digits = Number(digits.valueOf() * -1)
                display.setDigit(display.displayNumber(digits))
                return
            }

        if (previousOperator == "+") {
            digits = Number(digits.valueOf()) + Number(curVal.valueOf())
        } else if (previousOperator == "−") {
            digits = Number(curVal.valueOf()) - Number(digits.valueOf())
        } else if (previousOperator == "×") {
            digits = Number(curVal) * Number(digits.valueOf())
        } else if (previousOperator == "÷") {
            digits = Number(curVal) / Number(digits.valueOf())
        }

        if (op == "+" || op == "−" || op == "×" || op == "÷") {
            previousOperator = op
            curVal = digits.valueOf()
            digits = ""
            display.displayOperator(previousOperator)
            return
        }

        if (op == "=") {
            display.newLine("=", digits.valueOf())
        }

        curVal = 0
        previousOperator = ""

        if (op == "1/x") {
            digits = (1 / digits.valueOf()).toString()
        } else if (op == "x^2") {
            digits = (digits.valueOf() * digits.valueOf()).toString()
        } else if (op == "Abs") {
            digits = (Math.abs(digits.valueOf())).toString()
        } else if (op == "Int") {
            digits = (Math.floor(digits.valueOf())).toString()
        } else if (op == "√") {
            digits = Number(Math.sqrt(digits.valueOf()))
            display.newLine("√", digits.valueOf())
        } else if (op == "mc") {
            memory = 0;
        } else if (op == "m+") {
            memory += digits.valueOf()
        } else if (op == "mr") {
            digits = memory.toString()
        } else if (op == "m-") {
            memory = digits.valueOf()
        } else if (op == "backspace") {
            digits = digits.toString().slice(0, -1)
            display.clear()
            display.appendDigit(digits)
        } else if (op == "Off") {
            Qt.quit();
        }

        // Reset the state on 'C' operator or after
        // an error occurred
        if (op == "C" || display.isError) {
            display.clear()
            curVal = 0
            memory = 0
            lastOp = ""
            digits = ""
        }
    }