Evaluator.qml

Evaluator.qml

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtQuick.Layouts 1.3
import QtQuick.Window 2.2

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Evaluator")

    property string errorString: null

    ColumnLayout {
        anchors.fill: parent
        anchors.margins: 10

        Flickable {
            id: inputFlickable
            Layout.fillWidth: true
            Layout.fillHeight: true
            contentWidth: inputTextArea.width
            contentHeight: inputTextArea.height
            TextArea {
                id: inputTextArea
                selectByMouse: true
                text: "1 + 2 + 3"
                onTextChanged: evaluate()
            }
        }

        Flickable {
            id: outputFlickable
            Layout.fillWidth: true
            Layout.fillHeight: true
            contentWidth: outputTextArea.width
            contentHeight: outputTextArea.height
            TextArea {
                id: outputTextArea
                readOnly: true
            }
        }

        Text {
            text: errorString
            color: "red"
        }
    }

    function evaluate() {
        errorString = null;
        outputTextArea.text = "";

        try {
            outputTextArea.text = JSON.stringify(eval(inputTextArea.text), undefined, 2);
        } catch (err) {
            errorString = err.message;
        }
    }

    Component.onCompleted: evaluate()
}