// Copyright (C) 2017 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause #include "avatarExample.h" #include #include #include struct Expectations { QQmlEngine engine; void expectOne() { //![1] QQmlComponent component(&engine, "qrc:/exampleOne.qml"); QObject *object = component.create(); // The scarce resource will have been released automatically // by this point, after the binding expression was evaluated. bool expectedResult = (object->property("avatarWidth").toInt() == 100); delete object; //![1] Q_ASSERT(expectedResult); } void expectTwo() { //![2] QQmlComponent component(&engine, "qrc:/exampleTwo.qml"); QObject *object = component.create(); // The scarce resource will not have been released automatically // after the binding expression was evaluated. // Since the scarce resource was not released explicitly prior // to the binding expression being evaluated, we get: bool expectedResult = (object->property("avatar").isValid() == true); delete object; //![2] Q_ASSERT(expectedResult); } void expectThree() { //![3] QQmlComponent component(&engine, "qrc:/exampleThree.qml"); QObject *object = component.create(); // The resource was preserved explicitly during evaluation of the // JavaScript expression. Thus, during property assignment, the // scarce resource was still valid, and so we get: bool expectedResult = (object->property("avatar").isValid() == true); // The scarce resource will not be released until all references to // the resource are released, and the JavaScript garbage collector runs. delete object; //![3] Q_ASSERT(expectedResult); } void expectFour() { //![4] QQmlComponent component(&engine, "qrc:/exampleFour.qml"); QObject *object = component.create(); // The scarce resource was explicitly preserved by the client during // the importAvatar() function, and so the scarce resource // remains valid until the explicit call to releaseAvatar(). As such, // we get the expected results: bool expectedResultOne = (object->property("avatarOne").isValid() == true); bool expectedResultTwo = (object->property("avatarTwo").isValid() == false); // Because the scarce resource referenced by avatarTwo was released explicitly, // it will no longer be consuming any system resources (beyond what a normal // JS Object would; that small overhead will exist until the JS GC runs, as per // any other JavaScript object). delete object; //![4] Q_ASSERT(expectedResultOne); Q_ASSERT(expectedResultTwo); } void expectFive() { //![5] QQmlComponent component(&engine, "qrc:/exampleFive.qml"); QObject *object = component.create(); // We have the expected results: bool expectedResultOne = (object->property("avatarOne").isValid() == false); bool expectedResultTwo = (object->property("avatarTwo").isValid() == false); // Because although only avatarTwo was explicitly released, // avatarOne and avatarTwo were referencing the same // scarce resource. delete object; //![5] Q_ASSERT(expectedResultOne); Q_ASSERT(expectedResultTwo); } }; int main(int argc, char *argv[]) { QGuiApplication app(argc, argv); Expectations expectations; expectations.expectOne(); expectations.expectTwo(); expectations.expectThree(); expectations.expectFour(); expectations.expectFive(); }