Qt 5.7 | Qt WebEngine | WebEngine Demo Browser Example | downloadmanager.cpp Example File

Qt 5.7.1 Reference Documentation

# downloadmanager.cpp Example File

webenginewidgets/demobrowser/downloadmanager.cpp

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      #include "downloadmanager.h"

      #include "autosaver.h"
      #include "browserapplication.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 <QWebEngineSettings>
      #include <QWebEngineDownloadItem>

      /*!
          DownloadWidget is a widget that is displayed in the download manager list.
          It moves the data from the QWebEngineDownloadItem into the QFile as well
          as update the information/progressbar and report errors.
       */

      DownloadWidget::DownloadWidget(QWebEngineDownloadItem *download, QWidget *parent)
          : QWidget(parent)
          , m_bytesReceived(0)
          , m_download(download)
      {
          setupUi(this);
          QPalette p = downloadInfoLabel->palette();
          p.setColor(QPalette::Text, Qt::darkGray);
          downloadInfoLabel->setPalette(p);
          progressBar->setMaximum(0);
          connect(stopButton, SIGNAL(clicked()), this, SLOT(stop()));
          connect(openButton, SIGNAL(clicked()), this, SLOT(open()));

          if (download) {
              m_file.setFile(download->path());
              m_url = download->url();
          }

          init();
      }

      void DownloadWidget::init()
      {
          if (m_download) {
              connect(m_download.data(), SIGNAL(downloadProgress(qint64,qint64)),
                      this, SLOT(downloadProgress(qint64,qint64)));
              connect(m_download.data(), SIGNAL(finished()),
                      this, SLOT(finished()));
          }

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

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

      bool DownloadWidget::getFileName(bool promptForFileName)
      {
          QSettings settings;
          settings.beginGroup(QLatin1String("downloadmanager"));
          QString defaultLocation = QStandardPaths::writableLocation(QStandardPaths::DesktopLocation);
          if (m_file.absoluteDir().exists())
              defaultLocation = m_file.absolutePath();
          QString downloadDirectory = settings.value(QLatin1String("downloadDirectory"), defaultLocation).toString();
          if (!downloadDirectory.isEmpty())
              downloadDirectory += QLatin1Char('/');

          QString defaultFileName = QFileInfo(downloadDirectory, m_file.fileName()).absoluteFilePath();
          QString fileName = defaultFileName;
          if (promptForFileName) {
              fileName = QFileDialog::getSaveFileName(this, tr("Save File"), defaultFileName);
              if (fileName.isEmpty()) {
                  if (m_download)
                      m_download->cancel();
                  fileNameLabel->setText(tr("Download canceled: %1").arg(QFileInfo(defaultFileName).fileName()));
                  return false;
              }
          }
          m_file.setFile(fileName);

          if (m_download && m_download->state() == QWebEngineDownloadItem::DownloadRequested)
              m_download->setPath(m_file.absoluteFilePath());

          fileNameLabel->setText(m_file.fileName());
          return true;
      }

      void DownloadWidget::stop()
      {
          setUpdatesEnabled(false);
          stopButton->setEnabled(false);
          stopButton->hide();
          setUpdatesEnabled(true);
          if (m_download)
              m_download->cancel();

          emit statusChanged();
      }

      void DownloadWidget::open()
      {
          QUrl url = QUrl::fromLocalFile(m_file.absoluteFilePath());
          QDesktopServices::openUrl(url);
      }

      void DownloadWidget::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 DownloadWidget::updateInfoLabel()
      {
          qint64 bytesTotal = progressBar->maximum();

          // 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 (!downloadedSuccessfully()) {
              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 = tr("%1 of %2 - Stopped")
                      .arg(dataString(m_bytesReceived))
                      .arg(dataString(bytesTotal));
              } else
                  info = dataString(m_bytesReceived);
          }
          downloadInfoLabel->setText(info);
      }

      QString DownloadWidget::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 DownloadWidget::downloading() const
      {
          return (progressBar->isVisible());
      }

      bool DownloadWidget::downloadedSuccessfully() const
      {
          bool completed = m_download
                  && m_download->isFinished()
                  && m_download->state() == QWebEngineDownloadItem::DownloadCompleted;
          return completed || !stopButton->isVisible();
      }

      void DownloadWidget::finished()
      {
          if (m_download) {
              QWebEngineDownloadItem::DownloadState state = m_download->state();
              QString message;
              bool interrupted = false;

              switch (state) {
              case QWebEngineDownloadItem::DownloadRequested: // Fall-through.
              case QWebEngineDownloadItem::DownloadInProgress:
                  Q_UNREACHABLE();
                  break;
              case QWebEngineDownloadItem::DownloadCompleted:
                  break;
              case QWebEngineDownloadItem::DownloadCancelled:
                  message = QStringLiteral("Download cancelled");
                  interrupted = true;
                  break;
              case QWebEngineDownloadItem::DownloadInterrupted:
                  message = QStringLiteral("Download interrupted");
                  interrupted = true;
                  break;
              }

              if (interrupted) {
                  downloadInfoLabel->setText(message);
                  return;
              }
          }

          progressBar->hide();
          stopButton->setEnabled(false);
          stopButton->hide();
          updateInfoLabel();
          emit statusChanged();
      }

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

          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_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(QWebEngineDownloadItem *download)
      {
          DownloadWidget *widget = new DownloadWidget(download, this);
          addItem(widget);
      }

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

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

          bool remove = false;
          if (!widget->downloading()
              && BrowserApplication::instance()->privateBrowsing())
              remove = true;

          if (widget->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"), m_downloads[i]->m_file.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 (done && !url.isEmpty() && !fileName.isEmpty()) {
                  DownloadWidget *widget = new DownloadWidget(0, this);
                  widget->m_file.setFile(fileName);
                  widget->fileNameLabel->setText(widget->m_file.fileName());
                  widget->m_url = url;
                  widget->stopButton->setVisible(false);
                  widget->stopButton->setEnabled(false);
                  widget->progressBar->hide();
                  addItem(widget);
              }
              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()) {
                  beginRemoveRows(parent, i, i);
                  m_downloadManager->m_downloads.takeAt(i)->deleteLater();
                  endRemoveRows();
              }
          }
          m_downloadManager->m_autoSaver->changeOccurred();
          return true;
      }