examples/qtconcurrent/progressdialog/main.cpp
changeset 0 1918ee327afb
child 3 41300fa6a67c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/qtconcurrent/progressdialog/main.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,100 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#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
+