main.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2015 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** 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."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #ifdef QT_WIDGETS_LIB
  #include <QtWidgets/QApplication>
  #else
  #include <QtGui/QGuiApplication>
  #endif
  #include <QtQml/QQmlApplicationEngine>
  #include <QtQml/QQmlContext>
  #include <QtQuick/QQuickWindow>
  #include <QtGui/QImageReader>
  #include <QtCore/QCommandLineParser>
  #include <QtCore/QCommandLineOption>
  #include <QtCore/QDebug>
  #include <QtCore/QDir>
  #include <QtCore/QMimeDatabase>
  #include <QtCore/QStandardPaths>
  #include <QtCore/QUrl>

  static QStringList imageNameFilters()
  {
      QStringList result;
      QMimeDatabase mimeDatabase;
      foreach (const QByteArray &m, QImageReader::supportedMimeTypes()) {
          foreach (const QString &suffix, mimeDatabase.mimeTypeForName(m).suffixes())
              result.append(QStringLiteral("*.") + suffix);
      }
      return result;
  }

  int main(int argc, char* argv[])
  {
      // The reason to use QApplication is that QWidget-based dialogs
      // are the native dialogs on Qt-based platforms like KDE,
      // but they cannot be instantiated if this is a QGuiApplication.
  #ifdef QT_WIDGETS_LIB
      QApplication app(argc, argv);
  #else
      QGuiApplication app(argc, argv);
  #endif
      QQuickWindow::setDefaultAlphaBuffer(true);

      QCoreApplication::setApplicationName(QStringLiteral("Photosurface"));
      QCoreApplication::setOrganizationName(QStringLiteral("QtProject"));
      QCoreApplication::setApplicationVersion(QLatin1String(QT_VERSION_STR));
      QCommandLineParser parser;
      parser.setApplicationDescription(QStringLiteral("Qt Quick Demo - Photo Surface"));
      parser.addHelpOption();
      parser.addVersionOption();
      parser.addPositionalArgument(QStringLiteral("directory"),
                                   QStringLiteral("The image directory or URL to show."));
      parser.process(app);

      QUrl initialUrl;
      if (!parser.positionalArguments().isEmpty()) {
          initialUrl = QUrl::fromUserInput(parser.positionalArguments().first(),
                                           QDir::currentPath(), QUrl::AssumeLocalFile);
          if (!initialUrl.isValid()) {
              qWarning().nospace() << "Invalid argument: \""
                  << parser.positionalArguments().first() << "\": " << initialUrl.errorString();
              return 1;
          }
      }

      const QStringList nameFilters = imageNameFilters();

      QQmlApplicationEngine engine;
      QQmlContext *context = engine.rootContext();

      QUrl picturesLocationUrl = QUrl::fromLocalFile(QDir::homePath());
      const QStringList picturesLocations = QStandardPaths::standardLocations(QStandardPaths::PicturesLocation);
      if (!picturesLocations.isEmpty()) {
          picturesLocationUrl = QUrl::fromLocalFile(picturesLocations.first());
          if (initialUrl.isEmpty()
              && !QDir(picturesLocations.first()).entryInfoList(nameFilters, QDir::Files).isEmpty()) {
              initialUrl = picturesLocationUrl;
          }
      }

      context->setContextProperty(QStringLiteral("contextPicturesLocation"), picturesLocationUrl);
      context->setContextProperty(QStringLiteral("contextInitialUrl"), initialUrl);
      context->setContextProperty(QStringLiteral("contextImageNameFilters"), nameFilters);

      engine.load(QUrl("qrc:///photosurface.qml"));
      if (engine.rootObjects().isEmpty())
          return -1;

      return app.exec();
  }