qt5base-lts/examples/qtconcurrent/progressdialog/main.cpp
Jani Heikkinen 2b75c156b6 Updated BSD licensed file headers
Change-Id: I6441ff931dbd33b698d762e6f6784898f3f60fe7
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
2015-02-15 07:41:17 +00:00

89 lines
3.4 KiB
C++

/****************************************************************************
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** Copyright (C) 2015 The Qt Company Ltd.
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** This file is part of the examples of the Qt Toolkit.
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#include <QtWidgets>
#include <QtConcurrent>
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 connect 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();
}