main.cpp Example File

gestures/imagegestures/main.cpp
 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** BSD License Usage
 ** Alternatively, you may use this file under the terms of the BSD license
 ** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtWidgets>

 #include "mainwidget.h"

 static void showHelp(QCommandLineParser &parser, const QString errorMessage = QString())
 {
     QString text;
     QTextStream str(&text);
     str << "<html><head/><body>";
     if (!errorMessage.isEmpty())
         str << "<p>" << errorMessage << "</p>";
     str << "<pre>" << parser.helpText() << "</pre></body></html>";
     QMessageBox box(errorMessage.isEmpty() ? QMessageBox::Information : QMessageBox::Warning,
                     QGuiApplication::applicationDisplayName(), text,
                     QMessageBox::Ok);
     box.setTextInteractionFlags(Qt::TextBrowserInteraction);
     box.exec();
 }

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     QCoreApplication::setApplicationVersion(QT_VERSION_STR);
     QCoreApplication::setApplicationName(QStringLiteral("imagegestures"));
     QGuiApplication::setApplicationDisplayName(QStringLiteral("Image Gestures Example"));

     QCommandLineParser commandLineParser;
     const QCommandLineOption disablePanOption("no-pan", "Disable pan gesture");
     commandLineParser.addOption(disablePanOption);
     const QCommandLineOption disablePinchOption("no-pinch", "Disable pinch gesture");
     commandLineParser.addOption(disablePinchOption);
     const QCommandLineOption disableSwipeOption("no-swipe", "Disable swipe gesture");
     commandLineParser.addOption(disableSwipeOption);
     const QCommandLineOption helpOption = commandLineParser.addHelpOption();
     commandLineParser.addPositionalArgument(QStringLiteral("Directory"),
                                             QStringLiteral("Directory to display"));

     const QString description = QGuiApplication::applicationDisplayName()
         + QLatin1String("\n\nEnable \"debug\" on the logging category \"qt.examples.imagegestures\" in order to\n"
                         "in order to obtain verbose information about Qt's gesture event processing,\n"
                         "for example by setting the environment variables QT_LOGGING_RULES to\n"
                         "qt.examples.imagegestures.debug=true\n");
     commandLineParser.setApplicationDescription(description);

     commandLineParser.process(QCoreApplication::arguments());

     QStringList arguments = commandLineParser.positionalArguments();
     if (!arguments.isEmpty() && !QFileInfo(arguments.front()).isDir()) {
         showHelp(commandLineParser,
                  QLatin1Char('"') + QDir::toNativeSeparators(arguments.front())
                  + QStringLiteral("\" is not a directory."));
         return -1;
     }

     QList<Qt::GestureType> gestures;
     if (!commandLineParser.isSet(disablePanOption))
         gestures << Qt::PanGesture;
     if (!commandLineParser.isSet(disablePinchOption))
         gestures << Qt::PinchGesture;
     if (!commandLineParser.isSet(disableSwipeOption))
         gestures << Qt::SwipeGesture;

     MainWidget w;
     w.grabGestures(gestures);
     w.show();

     if (arguments.isEmpty()) {
         const QStringList picturesLocations = QStandardPaths::standardLocations(QStandardPaths::PicturesLocation);
         const QString directory =
             QFileDialog::getExistingDirectory(&w, "Select image folder",
                                               picturesLocations.isEmpty() ? QString() : picturesLocations.front());
         if (directory.isEmpty())
             return 0;
         arguments.append(directory);
     }

     w.openDirectory(arguments.front());

     return app.exec();
 }