Example: update imagescaling example

Updated the example to align with the Qt6 Example-Guideline.

https://wiki.qt.io/Qt6/Example-Guideline

Task-number: QTBUG-111165
Change-Id: Ibd9e7ce0d4dee90f6a693b81516d2f5b86345b1d
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit b5e9d418959a9d427c14468886470791527e157f)
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

examples/qtconcurrent/imagescaling/doc/src/qtconcurrent-imagescaling.qdoc

@@ -3,15 +3,17 @@
 
 /*!
     \example imagescaling
-    \title Image Scaling Example
-    \brief Demonstrates how to asynchronously download and scale images.
+    \meta tags {widgets, threads, network}
+    \title Image Scaling
     \ingroup qtconcurrentexamples
-    \image imagescaling_example.png
+    \brief Demonstrates how to asynchronously download and scale images.
 
     This example shows how to use the QFuture and QPromise classes to download a
     collection of images from the network and scale them, without blocking the UI.
 
-    The application consists of the the following steps:
+    \image imagescaling.webp
+
+    The application consists of the following steps:
 
     \list 1
     \li Download images form the list of URLs specified by the user.
@@ -148,4 +150,6 @@
 
     The rest of the code is straightforward, you can check the example project for
     more details.
+
+    \include examples-run.qdocinc
 */

examples/qtconcurrent/imagescaling/imagescaling.cpp

@@ -4,14 +4,12 @@
 #include "downloaddialog.h"
 
 #include <QNetworkReply>
-
-#include <qmath.h>
+#include <QtMath>
 
 #include <functional>
 
 Images::Images(QWidget *parent) : QWidget(parent), downloadDialog(new DownloadDialog(this))
 {
-    setWindowTitle(tr("Image downloading and scaling example"));
     resize(800, 600);
 
     addUrlsButton = new QPushButton(tr("Add URLs"));
@@ -90,7 +88,7 @@ void Images::process()
                     // Abort all pending requests
                     abortDownload();
                 })
-                .onFailed([this](const std::exception& ex) {
+                .onFailed([this](const std::exception &ex) {
                     updateStatus(tr(ex.what()));
                 });
 //! [6]
@@ -117,7 +115,7 @@ QFuture<QByteArray> Images::download(const QList<QUrl> &urls)
 //! [9]
 
 //! [10]
-    for (auto url : urls) {
+    for (const auto &url : urls) {
         QSharedPointer<QNetworkReply> reply(qnam.get(QNetworkRequest(url)));
         replies.push_back(reply);
 //! [10]
@@ -142,10 +140,10 @@ QFuture<QByteArray> Images::download(const QList<QUrl> &urls)
                 promise->finish();
             }
 //! [12]
-        }).onFailed([=] (QNetworkReply::NetworkError error) {
+        }).onFailed([promise] (QNetworkReply::NetworkError error) {
             promise->setException(std::make_exception_ptr(error));
             promise->finish();
-        }).onFailed([=] {
+        }).onFailed([promise] {
             const auto ex = std::make_exception_ptr(
                         std::runtime_error("Unknown error occurred while downloading."));
             promise->setException(ex);
@@ -164,7 +162,7 @@ QList<QImage> Images::scaled() const
 {
     QList<QImage> scaled;
     const auto data = downloadFuture.results();
-    for (auto imgData : data) {
+    for (const auto &imgData : data) {
         QImage image;
         image.loadFromData(imgData);
         if (image.isNull())

examples/qtconcurrent/imagescaling/main.cpp

@@ -1,15 +1,16 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-#include <QtWidgets>
-#include <QtConcurrent>
-
 #include "imagescaling.h"
+#include <QApplication>
 
 int main(int argc, char *argv[])
 {
     QApplication app(argc,argv);
+    app.setOrganizationName("QtProject");
+    app.setApplicationName(QObject::tr("Image Downloading and Scaling"));
 
     Images imageView;
+    imageView.setWindowTitle(QObject::tr("Image Downloading and Scaling"));
     imageView.show();
 
     return app.exec();