downloadmanager.cpp Example File | Qt WebKit Examples 5.5

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# downloadmanager.cpp Example File

webkitwidgets/browser/downloadmanager.cpp

    /****************************************************************************
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    #include "downloadmanager.h"

    #include "autosaver.h"
    #include "browserapplication.h"
    #include "networkaccessmanager.h"

    #include <math.h>

    #include <QtCore/QMetaEnum>
    #include <QtCore/QSettings>

    #include <QtGui/QDesktopServices>
    #include <QtWidgets/QFileDialog>
    #include <QtWidgets/QHeaderView>
    #include <QtWidgets/QFileIconProvider>

    #include <QtCore/QDebug>

    #include <QWebSettings>

    /*!
        DownloadItem is a widget that is displayed in the download manager list.
        It moves the data from the QNetworkReply into the QFile as well
        as update the information/progressbar and report errors.
     */
    DownloadItem::DownloadItem(QNetworkReply *reply, bool requestFileName, QWidget *parent)
        : QWidget(parent)
        , m_reply(reply)
        , m_requestFileName(requestFileName)
        , m_bytesReceived(0)
    {
        setupUi(this);
        QPalette p = downloadInfoLabel->palette();
        p.setColor(QPalette::Text, Qt::darkGray);
        downloadInfoLabel->setPalette(p);
        progressBar->setMaximum(0);
        tryAgainButton->hide();
        connect(stopButton, SIGNAL(clicked()), this, SLOT(stop()));
        connect(openButton, SIGNAL(clicked()), this, SLOT(open()));
        connect(tryAgainButton, SIGNAL(clicked()), this, SLOT(tryAgain()));

        init();
    }

    void DownloadItem::init()
    {
        if (!m_reply)
            return;

        // attach to the m_reply
        m_url = m_reply->url();
        m_reply->setParent(this);
        connect(m_reply, SIGNAL(readyRead()), this, SLOT(downloadReadyRead()));
        connect(m_reply, SIGNAL(error(QNetworkReply::NetworkError)),
                this, SLOT(error(QNetworkReply::NetworkError)));
        connect(m_reply, SIGNAL(downloadProgress(qint64,qint64)),
                this, SLOT(downloadProgress(qint64,qint64)));
        connect(m_reply, SIGNAL(metaDataChanged()),
                this, SLOT(metaDataChanged()));
        connect(m_reply, SIGNAL(finished()),
                this, SLOT(finished()));

        // reset info
        downloadInfoLabel->clear();
        progressBar->setValue(0);
        getFileName();

        // start timer for the download estimation
        m_downloadTime.start();

        if (m_reply->error() != QNetworkReply::NoError) {
            error(m_reply->error());
            finished();
        }
    }

    void DownloadItem::getFileName()
    {
        QSettings settings;
        settings.beginGroup(QLatin1String("downloadmanager"));
        QString defaultLocation = QStandardPaths::writableLocation(QStandardPaths::DesktopLocation);
        QString downloadDirectory = settings.value(QLatin1String("downloadDirectory"), defaultLocation).toString();
        if (!downloadDirectory.isEmpty())
            downloadDirectory += QLatin1Char('/');

        QString defaultFileName = saveFileName(downloadDirectory);
        QString fileName = defaultFileName;
        if (m_requestFileName) {
            fileName = QFileDialog::getSaveFileName(this, tr("Save File"), defaultFileName);
            if (fileName.isEmpty()) {
                m_reply->close();
                fileNameLabel->setText(tr("Download canceled: %1").arg(QFileInfo(defaultFileName).fileName()));
                return;
            }
        }
        m_output.setFileName(fileName);
        fileNameLabel->setText(QFileInfo(m_output.fileName()).fileName());
        if (m_requestFileName)
            downloadReadyRead();
    }

    QString DownloadItem::saveFileName(const QString &directory) const
    {
        // Move this function into QNetworkReply to also get file name sent from the server
        QString path = m_url.path();
        QFileInfo info(path);
        QString baseName = info.completeBaseName();
        QString endName = info.suffix();

        if (baseName.isEmpty()) {
            baseName = QLatin1String("unnamed_download");
            qDebug() << "DownloadManager:: downloading unknown file:" << m_url;
        }
        QString name = directory + baseName + QLatin1Char('.') + endName;
        if (QFile::exists(name)) {
            // already exists, don't overwrite
            int i = 1;
            do {
                name = directory + baseName + QLatin1Char('-') + QString::number(i++) + QLatin1Char('.') + endName;
            } while (QFile::exists(name));
        }
        return name;
    }

    void DownloadItem::stop()
    {
        setUpdatesEnabled(false);
        stopButton->setEnabled(false);
        stopButton->hide();
        tryAgainButton->setEnabled(true);
        tryAgainButton->show();
        setUpdatesEnabled(true);
        m_reply->abort();
    }

    void DownloadItem::open()
    {
        QFileInfo info(m_output);
        QUrl url = QUrl::fromLocalFile(info.absolutePath());
        QDesktopServices::openUrl(url);
    }

    void DownloadItem::tryAgain()
    {
        if (!tryAgainButton->isEnabled())
            return;

        tryAgainButton->setEnabled(false);
        tryAgainButton->setVisible(false);
        stopButton->setEnabled(true);
        stopButton->setVisible(true);
        progressBar->setVisible(true);

        QNetworkReply *r = BrowserApplication::networkAccessManager()->get(QNetworkRequest(m_url));
        if (m_reply)
            m_reply->deleteLater();
        if (m_output.exists())
            m_output.remove();
        m_reply = r;
        init();
        emit statusChanged();
    }

    void DownloadItem::downloadReadyRead()
    {
        if (m_requestFileName && m_output.fileName().isEmpty())
            return;
        if (!m_output.isOpen()) {
            // in case someone else has already put a file there
            if (!m_requestFileName)
                getFileName();
            if (!m_output.open(QIODevice::WriteOnly)) {
                downloadInfoLabel->setText(tr("Error opening save file: %1")
                        .arg(m_output.errorString()));
                stopButton->click();
                emit statusChanged();
                return;
            }
            emit statusChanged();
        }
        if (-1 == m_output.write(m_reply->readAll())) {
            downloadInfoLabel->setText(tr("Error saving: %1")
                    .arg(m_output.errorString()));
            stopButton->click();
        }
    }

    void DownloadItem::error(QNetworkReply::NetworkError)
    {
        qDebug() << "DownloadItem::error" << m_reply->errorString() << m_url;
        downloadInfoLabel->setText(tr("Network Error: %1").arg(m_reply->errorString()));
        tryAgainButton->setEnabled(true);
        tryAgainButton->setVisible(true);
    }

    void DownloadItem::metaDataChanged()
    {
        qDebug() << "DownloadItem::metaDataChanged: not handled.";
    }

    void DownloadItem::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
    {
        m_bytesReceived = bytesReceived;
        if (bytesTotal == -1) {
            progressBar->setValue(0);
            progressBar->setMaximum(0);
        } else {
            progressBar->setValue(bytesReceived);
            progressBar->setMaximum(bytesTotal);
        }
        updateInfoLabel();
    }

    void DownloadItem::updateInfoLabel()
    {
        if (m_reply->error() == QNetworkReply::NoError)
            return;

        qint64 bytesTotal = progressBar->maximum();
        bool running = !downloadedSuccessfully();

        // update info label
        double speed = m_bytesReceived * 1000.0 / m_downloadTime.elapsed();
        double timeRemaining = ((double)(bytesTotal - m_bytesReceived)) / speed;
        QString timeRemainingString = tr("seconds");
        if (timeRemaining > 60) {
            timeRemaining = timeRemaining / 60;
            timeRemainingString = tr("minutes");
        }
        timeRemaining = floor(timeRemaining);

        // When downloading the eta should never be 0
        if (timeRemaining == 0)
            timeRemaining = 1;

        QString info;
        if (running) {
            QString remaining;
            if (bytesTotal != 0)
                remaining = tr("- %4 %5 remaining")
                .arg(timeRemaining)
                .arg(timeRemainingString);
            info = tr("%1 of %2 (%3/sec) %4")
                .arg(dataString(m_bytesReceived))
                .arg(bytesTotal == 0 ? tr("?") : dataString(bytesTotal))
                .arg(dataString((int)speed))
                .arg(remaining);
        } else {
            if (m_bytesReceived == bytesTotal)
                info = dataString(m_output.size());
            else
                info = tr("%1 of %2 - Stopped")
                    .arg(dataString(m_bytesReceived))
                    .arg(dataString(bytesTotal));
        }
        downloadInfoLabel->setText(info);
    }

    QString DownloadItem::dataString(int size) const
    {
        QString unit;
        if (size < 1024) {
            unit = tr("bytes");
        } else if (size < 1024*1024) {
            size /= 1024;
            unit = tr("kB");
        } else {
            size /= 1024*1024;
            unit = tr("MB");
        }
        return QString(QLatin1String("%1 %2")).arg(size).arg(unit);
    }

    bool DownloadItem::downloading() const
    {
        return (progressBar->isVisible());
    }

    bool DownloadItem::downloadedSuccessfully() const
    {
        return (stopButton->isHidden() && tryAgainButton->isHidden());
    }

    void DownloadItem::finished()
    {
        progressBar->hide();
        stopButton->setEnabled(false);
        stopButton->hide();
        m_output.close();
        updateInfoLabel();
        emit statusChanged();
    }

    /*!
        DownloadManager is a Dialog that contains a list of DownloadItems

        It is a basic download manager.  It only downloads the file, doesn't do BitTorrent,
        extract zipped files or anything fancy.
      */
    DownloadManager::DownloadManager(QWidget *parent)
        : QDialog(parent)
        , m_autoSaver(new AutoSaver(this))
        , m_manager(BrowserApplication::networkAccessManager())
        , m_iconProvider(0)
        , m_removePolicy(Never)
    {
        setupUi(this);
        downloadsView->setShowGrid(false);
        downloadsView->verticalHeader()->hide();
        downloadsView->horizontalHeader()->hide();
        downloadsView->setAlternatingRowColors(true);
        downloadsView->horizontalHeader()->setStretchLastSection(true);
        m_model = new DownloadModel(this);
        downloadsView->setModel(m_model);
        connect(cleanupButton, SIGNAL(clicked()), this, SLOT(cleanup()));
        load();
    }

    DownloadManager::~DownloadManager()
    {
        m_autoSaver->changeOccurred();
        m_autoSaver->saveIfNeccessary();
        if (m_iconProvider)
            delete m_iconProvider;
    }

    int DownloadManager::activeDownloads() const
    {
        int count = 0;
        for (int i = 0; i < m_downloads.count(); ++i) {
            if (m_downloads.at(i)->stopButton->isEnabled())
                ++count;
        }
        return count;
    }

    void DownloadManager::download(const QNetworkRequest &request, bool requestFileName)
    {
        if (request.url().isEmpty())
            return;
        handleUnsupportedContent(m_manager->get(request), requestFileName);
    }

    void DownloadManager::handleUnsupportedContent(QNetworkReply *reply, bool requestFileName)
    {
        if (!reply || reply->url().isEmpty())
            return;
        QVariant header = reply->header(QNetworkRequest::ContentLengthHeader);
        bool ok;
        int size = header.toInt(&ok);
        if (ok && size == 0)
            return;

        qDebug() << "DownloadManager::handleUnsupportedContent" << reply->url() << "requestFileName" << requestFileName;
        DownloadItem *item = new DownloadItem(reply, requestFileName, this);
        addItem(item);
    }

    void DownloadManager::addItem(DownloadItem *item)
    {
        connect(item, SIGNAL(statusChanged()), this, SLOT(updateRow()));
        int row = m_downloads.count();
        m_model->beginInsertRows(QModelIndex(), row, row);
        m_downloads.append(item);
        m_model->endInsertRows();
        updateItemCount();
        if (row == 0)
            show();
        downloadsView->setIndexWidget(m_model->index(row, 0), item);
        QIcon icon = style()->standardIcon(QStyle::SP_FileIcon);
        item->fileIcon->setPixmap(icon.pixmap(48, 48));
        downloadsView->setRowHeight(row, item->sizeHint().height());
    }

    void DownloadManager::updateRow()
    {
        DownloadItem *item = qobject_cast<DownloadItem*>(sender());
        int row = m_downloads.indexOf(item);
        if (-1 == row)
            return;
        if (!m_iconProvider)
            m_iconProvider = new QFileIconProvider();
        QIcon icon = m_iconProvider->icon(item->m_output.fileName());
        if (icon.isNull())
            icon = style()->standardIcon(QStyle::SP_FileIcon);
        item->fileIcon->setPixmap(icon.pixmap(48, 48));
        downloadsView->setRowHeight(row, item->minimumSizeHint().height());

        bool remove = false;
        QWebSettings *globalSettings = QWebSettings::globalSettings();
        if (!item->downloading()
            && globalSettings->testAttribute(QWebSettings::PrivateBrowsingEnabled))
            remove = true;

        if (item->downloadedSuccessfully()
            && removePolicy() == DownloadManager::SuccessFullDownload) {
            remove = true;
        }
        if (remove)
            m_model->removeRow(row);

        cleanupButton->setEnabled(m_downloads.count() - activeDownloads() > 0);
    }

    DownloadManager::RemovePolicy DownloadManager::removePolicy() const
    {
        return m_removePolicy;
    }

    void DownloadManager::setRemovePolicy(RemovePolicy policy)
    {
        if (policy == m_removePolicy)
            return;
        m_removePolicy = policy;
        m_autoSaver->changeOccurred();
    }

    void DownloadManager::save() const
    {
        QSettings settings;
        settings.beginGroup(QLatin1String("downloadmanager"));
        QMetaEnum removePolicyEnum = staticMetaObject.enumerator(staticMetaObject.indexOfEnumerator("RemovePolicy"));
        settings.setValue(QLatin1String("removeDownloadsPolicy"), QLatin1String(removePolicyEnum.valueToKey(m_removePolicy)));
        settings.setValue(QLatin1String("size"), size());
        if (m_removePolicy == Exit)
            return;

        for (int i = 0; i < m_downloads.count(); ++i) {
            QString key = QString(QLatin1String("download_%1_")).arg(i);
            settings.setValue(key + QLatin1String("url"), m_downloads[i]->m_url);
            settings.setValue(key + QLatin1String("location"), QFileInfo(m_downloads[i]->m_output).filePath());
            settings.setValue(key + QLatin1String("done"), m_downloads[i]->downloadedSuccessfully());
        }
        int i = m_downloads.count();
        QString key = QString(QLatin1String("download_%1_")).arg(i);
        while (settings.contains(key + QLatin1String("url"))) {
            settings.remove(key + QLatin1String("url"));
            settings.remove(key + QLatin1String("location"));
            settings.remove(key + QLatin1String("done"));
            key = QString(QLatin1String("download_%1_")).arg(++i);
        }
    }

    void DownloadManager::load()
    {
        QSettings settings;
        settings.beginGroup(QLatin1String("downloadmanager"));
        QSize size = settings.value(QLatin1String("size")).toSize();
        if (size.isValid())
            resize(size);
        QByteArray value = settings.value(QLatin1String("removeDownloadsPolicy"), QLatin1String("Never")).toByteArray();
        QMetaEnum removePolicyEnum = staticMetaObject.enumerator(staticMetaObject.indexOfEnumerator("RemovePolicy"));
        m_removePolicy = removePolicyEnum.keyToValue(value) == -1 ?
                            Never :
                            static_cast<RemovePolicy>(removePolicyEnum.keyToValue(value));

        int i = 0;
        QString key = QString(QLatin1String("download_%1_")).arg(i);
        while (settings.contains(key + QLatin1String("url"))) {
            QUrl url = settings.value(key + QLatin1String("url")).toUrl();
            QString fileName = settings.value(key + QLatin1String("location")).toString();
            bool done = settings.value(key + QLatin1String("done"), true).toBool();
            if (!url.isEmpty() && !fileName.isEmpty()) {
                DownloadItem *item = new DownloadItem(0, this);
                item->m_output.setFileName(fileName);
                item->fileNameLabel->setText(QFileInfo(item->m_output.fileName()).fileName());
                item->m_url = url;
                item->stopButton->setVisible(false);
                item->stopButton->setEnabled(false);
                item->tryAgainButton->setVisible(!done);
                item->tryAgainButton->setEnabled(!done);
                item->progressBar->setVisible(!done);
                addItem(item);
            }
            key = QString(QLatin1String("download_%1_")).arg(++i);
        }
        cleanupButton->setEnabled(m_downloads.count() - activeDownloads() > 0);
    }

    void DownloadManager::cleanup()
    {
        if (m_downloads.isEmpty())
            return;
        m_model->removeRows(0, m_downloads.count());
        updateItemCount();
        if (m_downloads.isEmpty() && m_iconProvider) {
            delete m_iconProvider;
            m_iconProvider = 0;
        }
        m_autoSaver->changeOccurred();
    }

    void DownloadManager::updateItemCount()
    {
        int count = m_downloads.count();
        itemCount->setText(count == 1 ? tr("1 Download") : tr("%1 Downloads").arg(count));
    }

    DownloadModel::DownloadModel(DownloadManager *downloadManager, QObject *parent)
        : QAbstractListModel(parent)
        , m_downloadManager(downloadManager)
    {
    }

    QVariant DownloadModel::data(const QModelIndex &index, int role) const
    {
        if (index.row() < 0 || index.row() >= rowCount(index.parent()))
            return QVariant();
        if (role == Qt::ToolTipRole)
            if (!m_downloadManager->m_downloads.at(index.row())->downloadedSuccessfully())
                return m_downloadManager->m_downloads.at(index.row())->downloadInfoLabel->text();
        return QVariant();
    }

    int DownloadModel::rowCount(const QModelIndex &parent) const
    {
        return (parent.isValid()) ? 0 : m_downloadManager->m_downloads.count();
    }

    bool DownloadModel::removeRows(int row, int count, const QModelIndex &parent)
    {
        if (parent.isValid())
            return false;

        int lastRow = row + count - 1;
        for (int i = lastRow; i >= row; --i) {
            if (m_downloadManager->m_downloads.at(i)->downloadedSuccessfully()
                || m_downloadManager->m_downloads.at(i)->tryAgainButton->isEnabled()) {
                beginRemoveRows(parent, i, i);
                m_downloadManager->m_downloads.takeAt(i)->deleteLater();
                endRemoveRows();
            }
        }
        m_downloadManager->m_autoSaver->changeOccurred();
        return true;
    }