|  | Home · All Classes · Main Classes · Grouped Classes · Modules · Functions |

# main.cpp Example File
qtconcurrent/progressdialog/main.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2007-2008 Trolltech ASA. All rights reserved.
     **
     ** This file is part of the example classes of the Qt Toolkit.
     **
     ** This file may be used under the terms of the GNU General Public
     ** License versions 2.0 or 3.0 as published by the Free Software
     ** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
     ** included in the packaging of this file.  Alternatively you may (at
     ** your option) use any later version of the GNU General Public
     ** License if such license has been publicly approved by Trolltech ASA
     ** (or its successors, if any) and the KDE Free Qt Foundation.
     **
     ** Please review the following information to ensure GNU General
     ** Public Licensing requirements will be met:
     ** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
     ** you are unsure which license is appropriate for your use, please
     ** review the following information:
     ** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
     ** or contact the sales department at sales@trolltech.com.
     **
     ** In addition, as a special exception, Trolltech, as the sole
     ** copyright holder for Qt Designer, grants users of the Qt/Eclipse
     ** Integration plug-in the right for the Qt/Eclipse Integration to
     ** link to functionality provided by Qt Designer and its related
     ** libraries.
     **
     ** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
     ** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
     ** granted herein.
     **
     ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
     ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     **
     ****************************************************************************/

     #include <QtGui>

     #ifndef QT_NO_CONCURRENT

     using namespace QtConcurrent;

     const int iterations = 20;

     void spin(int &iteration)
     {
         const int work = 1000 * 1000 * 40;
         volatile int v = 0;
         for (int j = 0; j < work; ++j)
             ++v;

         qDebug() << "iteration" << iteration << "in thread" << QThread::currentThreadId();
     }

     int main(int argc, char **argv)
     {
         QApplication app(argc, argv);

         // Prepare the vector.
         QVector<int> vector;
         for (int i = 0; i < iterations; ++i)
             vector.append(i);

         // Create a progress dialog.
         QProgressDialog dialog;
         dialog.setLabelText(QString("Progressing using %1 thread(s)...").arg(QThread::idealThreadCount()));

         // Create a QFutureWatcher and conncect signals and slots.
         QFutureWatcher<void> futureWatcher;
         QObject::connect(&futureWatcher, SIGNAL(finished()), &dialog, SLOT(reset()));
         QObject::connect(&dialog, SIGNAL(canceled()), &futureWatcher, SLOT(cancel()));
         QObject::connect(&futureWatcher, SIGNAL(progressRangeChanged(int, int)), &dialog, SLOT(setRange(int, int)));
         QObject::connect(&futureWatcher, SIGNAL(progressValueChanged(int)), &dialog, SLOT(setValue(int)));

         // Start the computation.
         futureWatcher.setFuture(QtConcurrent::map(vector, spin));

         // Display the dialog and start the event loop.
         dialog.exec();

         futureWatcher.waitForFinished();

         // Query the future to check if was canceled.
         qDebug() << "Canceled?" << futureWatcher.future().isCanceled();
     }

     #else

     int main()
     {
             qDebug() << "Qt Concurrent is not yet supported on this platform";
     }

     #endif