main.cpp Example File | Qt Widgets 5.12.7

Qt 5.12 | Qt Widgets | Image Gestures Example | main.cpp Example File

Qt 5.12.7 Reference Documentation

# 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();
      }