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();
  }