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// Copyright (C) 2025 Jarek Kobus
// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "imagescaling.h"
#include "downloaddialog.h"
#include <QThreadFunction>
#include <QNetworkReplyWrapper>
#include <QTaskTree>
using namespace QtTaskTree;
Images::Images(QWidget *parent)
: QWidget(parent)
, cancelButton(new QPushButton(tr("Cancel")))
, imagesLayout(new QGridLayout)
, statusBar(new QStatusBar)
{
resize(800, 600);
auto addUrlsButton = new QPushButton(tr("Add URLs"));
connect(addUrlsButton, &QPushButton::clicked, this, &Images::process);
cancelButton->setEnabled(false);
connect(cancelButton, &QPushButton::clicked, this, [this] { taskTreeRunner.cancel(); });
QHBoxLayout *buttonLayout = new QHBoxLayout;
buttonLayout->addWidget(addUrlsButton);
buttonLayout->addWidget(cancelButton);
buttonLayout->addStretch();
auto mainLayout = new QVBoxLayout;
mainLayout->addLayout(buttonLayout);
mainLayout->addLayout(imagesLayout);
mainLayout->addStretch();
mainLayout->addWidget(statusBar);
setLayout(mainLayout);
}
//! [6]
static void scale(QPromise<QImage> &promise, const QByteArray &data)
{
const auto image = QImage::fromData(data);
if (image.isNull())
promise.future().cancel();
else
promise.addResult(image.scaled(100, 100, Qt::KeepAspectRatio));
}
//! [6]
void Images::process()
{
//! [0]
DownloadDialog dialog(this);
if (dialog.exec() != QDialog::Accepted)
return;
const QList<QUrl> urls = dialog.getUrls();
initLayout(urls.size());
//! [0]
//! [1]
const ListIterator iterator(urls);
const Storage<QByteArray> storage;
//! [1]
//! [3]
const auto onRootSetup = [this] {
statusBar->showMessage(tr("Downloading and Scaling..."));
cancelButton->setEnabled(true);
};
const auto onRootDone = [this](DoneWith result) {
const QString message = result == DoneWith::Cancel ? tr("Canceled.") : tr("Finished.");
statusBar->showMessage(message);
cancelButton->setEnabled(false);
};
//! [3]
//! [4]
const auto onDownloadSetup = [this, iterator](QNetworkReplyWrapper &task) {
task.setNetworkAccessManager(&qnam);
task.setRequest(QNetworkRequest(*iterator));
};
const auto onDownloadDone = [this, storage, iterator](const QNetworkReplyWrapper &task,
DoneWith result) {
const int it = iterator.iteration();
if (result == DoneWith::Success)
*storage = task.reply()->readAll();
else if (result == DoneWith::Error)
labels[it]->setText(tr("Download\nError.\nCode: %1.").arg(task.reply()->error()));
else
labels[it]->setText(tr("Canceled."));
};
//! [4]
//! [5]
const auto onScaleSetup = [storage](QThreadFunction<QImage> &task) {
task.setThreadFunctionData(&scale, *storage);
};
const auto onScaleDone = [this, iterator](const QThreadFunction<QImage> &task,
DoneWith result) {
const int it = iterator.iteration();
if (result == DoneWith::Success)
labels[it]->setPixmap(QPixmap::fromImage(task.result()));
else if (result == DoneWith::Error)
labels[it]->setText(tr("Image\nData\nError."));
else
labels[it]->setText(tr("Canceled."));
};
//! [5]
//! [2]
const Group recipe = For (iterator) >> Do {
finishAllAndSuccess,
parallel,
onGroupSetup(onRootSetup),
Group {
storage,
QNetworkReplyWrapperTask(onDownloadSetup, onDownloadDone),
QThreadFunctionTask<QImage>(onScaleSetup, onScaleDone)
},
onGroupDone(onRootDone)
};
taskTreeRunner.start(recipe);
//! [2]
}
void Images::initLayout(qsizetype count)
{
// Clean old images
QLayoutItem *child;
while ((child = imagesLayout->takeAt(0)) != nullptr) {
child->widget()->setParent(nullptr);
delete child->widget();
delete child;
}
labels.clear();
// Init the images layout for the new images
const auto dim = int(qSqrt(qreal(count))) + 1;
for (int i = 0; i < dim; ++i) {
for (int j = 0; j < dim; ++j) {
QLabel *imageLabel = new QLabel;
imageLabel->setFixedSize(100, 100);
imageLabel->setAlignment(Qt::AlignCenter);
imagesLayout->addWidget(imageLabel, i, j);
labels.append(imageLabel);
}
}
}