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Diffstat (limited to 'tests/manual/wasm/eventloop/main_exec/main.cpp')
-rw-r--r-- | tests/manual/wasm/eventloop/main_exec/main.cpp | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/tests/manual/wasm/eventloop/main_exec/main.cpp b/tests/manual/wasm/eventloop/main_exec/main.cpp new file mode 100644 index 0000000000..17eccafe18 --- /dev/null +++ b/tests/manual/wasm/eventloop/main_exec/main.cpp @@ -0,0 +1,67 @@ +// Copyright (C) 2021 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only +#include <QtGui> + +// This example demonstrates how the standard Qt main() +// pattern works on Emscripten/WebAssambly, where exec() +// does not return. + +class ClickWindow: public QRasterWindow +{ +public: + ClickWindow() { + qDebug() << "ClickWindow constructor"; + } + ~ClickWindow() { + qDebug() << "ClickWindow destructor"; + } + + void paintEvent(QPaintEvent *ev) override { + QPainter p(this); + p.fillRect(ev->rect(), QColorConstants::Svg::deepskyblue); + p.drawText(50, 100, "Application has started. See the developer tools console for debug output"); + } + + void mousePressEvent(QMouseEvent *) override { + qDebug() << "mousePressEvent(): calling QGuiApplication::quit()"; + QGuiApplication::quit(); + } +}; + +int main(int argc, char **argv) +{ + qDebug() << "main(): Creating QGuiApplication object"; + QGuiApplication app(argc, argv); + + QObject::connect(&app, &QCoreApplication::aboutToQuit, [](){ + qDebug() << "QCoreApplication::aboutToQuit"; + }); + + ClickWindow window; + window.show(); + + qDebug() << "main(): calling exec()"; + app.exec(); + + // The exec() call above never returns; instead, a JavaScript exception + // is thrown such that control returns to the browser while preserving + // the C++ stack. + + // This means that the window object above is not destroyed, and that + // shutdown code after exec() does not run. + + qDebug() << "main(): after exit"; // <- will not be printed +} + +// Global variables are created before main() as usual, but not destroyed +class Global +{ +public: + Global() { + qDebug() << "Global constructor"; + } + ~Global() { + qDebug() << "Global destructor"; // <- will not be printed + } +}; +Global global; |