////  Copyright (c) 2019 High Fidelity, Inc. All rights reserved.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include <QGuiApplication>#include <QQmlApplicationEngine>#include <QQmlContext> #include "treemodel.h" int main(int argc, char *argv[]){    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);     QGuiApplication app(argc, argv);     QQmlApplicationEngine engine;     // expose model    TreeModel model;    engine.rootContext()->setContextProperty("theModel", &model);     const QUrl url(QStringLiteral("qrc:/qml/main.qml"));    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated, &app, [url](QObject *obj, const QUrl &objUrl) {        if (!obj && url == objUrl) {            // failure loading main.qml            QCoreApplication::exit(-1);        }    }, Qt::QueuedConnection);    engine.load(url);     return app.exec();}