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/**************************************************************************** ** ** 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. In ** addition, as a special exception, Trolltech gives you certain ** additional rights. These rights are described in the Trolltech GPL ** Exception version 1.2, which can be found at ** http://www.trolltech.com/products/qt/gplexception/ and in the file ** GPL_EXCEPTION.txt in this package. ** ** 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 "imagescaling.h" #include "math.h" #ifndef QT_NO_CONCURRENT const int imageSize = 100; QImage scale(const QString &imageFileName) { QImage image(imageFileName); return image.scaled(QSize(imageSize, imageSize), Qt::IgnoreAspectRatio, Qt::SmoothTransformation); } Images::Images(QWidget *parent) : QWidget(parent) { setWindowTitle(tr("Image loading and scaling example")); resize(800, 600); imageScaling = new QFutureWatcher<QImage>(this); connect(imageScaling, SIGNAL(resultReadyAt(int)), SLOT(showImage(int))); connect(imageScaling, SIGNAL(finished()), SLOT(finished())); openButton = new QPushButton(tr("Open Images")); connect(openButton, SIGNAL(clicked()), SLOT(open())); cancelButton = new QPushButton(tr("Cancel")); cancelButton->setEnabled(false); connect(cancelButton, SIGNAL(clicked()), imageScaling, SLOT(cancel())); QHBoxLayout *buttonLayout = new QHBoxLayout(); buttonLayout->addWidget(openButton); buttonLayout->addWidget(cancelButton); buttonLayout->addStretch(); imagesLayout = new QGridLayout(); mainLayout = new QVBoxLayout(); mainLayout->addLayout(buttonLayout); mainLayout->addLayout(imagesLayout); mainLayout->addStretch(); setLayout(mainLayout); } Images::~Images() { imageScaling->cancel(); imageScaling->waitForFinished(); } void Images::open() { // Cancel and wait if we are already loading images. if (imageScaling->isRunning()) { imageScaling->cancel(); imageScaling->waitForFinished(); } // Show a file open dialog at QDesktopServices::PicturesLocation. QStringList files = QFileDialog::getOpenFileNames(this, tr("Select Images"), QDesktopServices::storageLocation(QDesktopServices::PicturesLocation), "*.jpg *.png"); if (files.count() == 0) return; // Do a simple layout. qDeleteAll(labels); labels.clear(); int dim = sqrt(qreal(files.count())) + 1; for (int i = 0; i < dim; ++i) { for (int j = 0; j < dim; ++j) { QLabel *imageLabel = new QLabel; imageLabel->setFixedSize(imageSize,imageSize); imagesLayout->addWidget(imageLabel,i,j); labels.append(imageLabel); } } // Use mapped to run the thread safe scale function on the files. imageScaling->setFuture(QtConcurrent::mapped(files, scale)); openButton->setEnabled(false); cancelButton->setEnabled(true); } void Images::showImage(int num) { labels[num]->setPixmap(QPixmap::fromImage(imageScaling->resultAt(num))); } void Images::finished() { openButton->setEnabled(true); cancelButton->setEnabled(false); } #endif // QT_NO_CONCURRENT
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