source: trunk/examples/qtconcurrent/imagescaling/imagescaling.cpp@ 886

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#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()));
   
    pauseButton = new QPushButton(tr("Pause/Resume"));
    pauseButton->setEnabled(false);
    connect(pauseButton, SIGNAL(clicked()), imageScaling, SLOT(togglePaused()));
   
    QHBoxLayout *buttonLayout = new QHBoxLayout();
    buttonLayout->addWidget(openButton);
    buttonLayout->addWidget(cancelButton);
    buttonLayout->addWidget(pauseButton);
    buttonLayout->addStretch();

    imagesLayout = new QGridLayout();

    mainLayout = new QVBoxLayout();
    mainLayout->addLayout(buttonLayout);
    mainLayout->addLayout(imagesLayout);
    mainLayout->addStretch();
    setLayout(mainLayout);
}

Images::~Images()
{
    imageScaling->cancel();
    imageScaling->waitForFinished();
}