82f14a95b5
Add minimal examples which demonstrates how exec() works on Qt for WebAssembly and how to implement main() without calling QApplication::exec(). Change-Id: I44f1d16af19c538380cc56faf3f0f4cc9d66cf11 Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
96 lines
3.6 KiB
C++
96 lines
3.6 KiB
C++
/****************************************************************************
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**
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** Copyright (C) 2021 The Qt Company Ltd.
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** Contact: https://www.qt.io/licensing/
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** Commercial License Usage
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** Licensees holding valid commercial Qt licenses may use this file in
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** accordance with the commercial license agreement provided with the
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** Software or, alternatively, in accordance with the terms contained in
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** a written agreement between you and The Qt Company. For licensing terms
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** and conditions see https://www.qt.io/terms-conditions. For further
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** information use the contact form at https://www.qt.io/contact-us.
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**
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** BSD License Usage
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** Alternatively, you may use this file under the terms of the BSD license
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** as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of The Qt Company Ltd nor the names of its
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** contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include <QtGui>
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#include <QtWidgets>
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// This example show how calling QDialog::exec() shows the dialog,
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// but does not return.
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class ClickWindow: public QRasterWindow
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{
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public:
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ClickWindow() {
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qDebug() << "ClickWindow constructor";
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}
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~ClickWindow() {
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qDebug() << "ClickWindow destructor";
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}
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void paintEvent(QPaintEvent *ev) override {
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QPainter p(this);
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p.fillRect(ev->rect(), QColorConstants::Svg::deepskyblue);
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p.drawText(50, 100, "Application has started. See the developer tools console for debug output");
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}
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void mousePressEvent(QMouseEvent *) override {
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qDebug() << "mousePressEvent(): calling QMessageBox::exec()";
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QMessageBox messageBox;
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messageBox.setText("Hello! This is a message box.");
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connect(&messageBox, &QMessageBox::buttonClicked, [](QAbstractButton *button) {
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qDebug() << "Button Clicked" << button;
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});
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messageBox.exec(); // <-- does not return
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qDebug() << "mousePressEvent(): done"; // <--- will not be printed
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}
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};
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int main(int argc, char **argv)
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{
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QApplication app(argc, argv);
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ClickWindow window;
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window.show();
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return app.exec();
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}
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