Qt 5.11 | Qt WebEngine | WebEngine Widgets Simple Browser Example | downloadwidget.cpp Example File

Qt 5.11.3 Reference Documentation

# downloadwidget.cpp Example File

webenginewidgets/simplebrowser/downloadwidget.cpp

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      #include "downloadwidget.h"

      #include <QFileInfo>
      #include <QUrl>
      #include <QWebEngineDownloadItem>

      DownloadWidget::DownloadWidget(QWebEngineDownloadItem *download, QWidget *parent)
          : QFrame(parent)
          , m_download(download)
          , m_timeAdded(QTime::currentTime())
      {
          setupUi(this);
          m_dstName->setText(QFileInfo(m_download->path()).fileName());
          m_srcUrl->setText(m_download->url().toDisplayString());

          connect(m_cancelButton, &QPushButton::clicked,
                  [this](bool) {
              if (m_download->state() == QWebEngineDownloadItem::DownloadInProgress)
                  m_download->cancel();
              else
                  emit removeClicked(this);
          });

          connect(m_download, &QWebEngineDownloadItem::downloadProgress,
                  this, &DownloadWidget::updateWidget);

          connect(m_download, &QWebEngineDownloadItem::stateChanged,
                  this, &DownloadWidget::updateWidget);

          updateWidget();
      }

      inline QString DownloadWidget::withUnit(qreal bytes)
      {
          if (bytes < (1 << 10))
              return tr("%L1 B").arg(bytes);
          else if (bytes < (1 << 20))
              return tr("%L1 KiB").arg(bytes / (1 << 10), 0, 'f', 2);
          else if (bytes < (1 << 30))
              return tr("%L1 MiB").arg(bytes / (1 << 20), 0, 'f', 2);
          else
              return tr("%L1 GiB").arg(bytes / (1 << 30), 0, 'f', 2);
      }

      void DownloadWidget::updateWidget()
      {
          qreal totalBytes = m_download->totalBytes();
          qreal receivedBytes = m_download->receivedBytes();
          qreal bytesPerSecond = receivedBytes / m_timeAdded.elapsed() * 1000;

          auto state = m_download->state();
          switch (state) {
          case QWebEngineDownloadItem::DownloadRequested:
              Q_UNREACHABLE();
              break;
          case QWebEngineDownloadItem::DownloadInProgress:
              if (totalBytes >= 0) {
                  m_progressBar->setValue(qRound(100 * receivedBytes / totalBytes));
                  m_progressBar->setDisabled(false);
                  m_progressBar->setFormat(
                      tr("%p% - %1 of %2 downloaded - %3/s")
                      .arg(withUnit(receivedBytes))
                      .arg(withUnit(totalBytes))
                      .arg(withUnit(bytesPerSecond)));
              } else {
                  m_progressBar->setValue(0);
                  m_progressBar->setDisabled(false);
                  m_progressBar->setFormat(
                      tr("unknown size - %1 downloaded - %2/s")
                      .arg(withUnit(receivedBytes))
                      .arg(withUnit(bytesPerSecond)));
              }
              break;
          case QWebEngineDownloadItem::DownloadCompleted:
              m_progressBar->setValue(100);
              m_progressBar->setDisabled(true);
              m_progressBar->setFormat(
                  tr("completed - %1 downloaded - %2/s")
                  .arg(withUnit(receivedBytes))
                  .arg(withUnit(bytesPerSecond)));
              break;
          case QWebEngineDownloadItem::DownloadCancelled:
              m_progressBar->setValue(0);
              m_progressBar->setDisabled(true);
              m_progressBar->setFormat(
                  tr("cancelled - %1 downloaded - %2/s")
                  .arg(withUnit(receivedBytes))
                  .arg(withUnit(bytesPerSecond)));
              break;
          case QWebEngineDownloadItem::DownloadInterrupted:
              m_progressBar->setValue(0);
              m_progressBar->setDisabled(true);
              m_progressBar->setFormat(
                  tr("interrupted: %1")
                  .arg(m_download->interruptReasonString()));
              break;
          }

          if (state == QWebEngineDownloadItem::DownloadInProgress) {
              static QIcon cancelIcon(QStringLiteral(":process-stop.png"));
              m_cancelButton->setIcon(cancelIcon);
              m_cancelButton->setToolTip(tr("Stop downloading"));
          } else {
              static QIcon removeIcon(QStringLiteral(":edit-clear.png"));
              m_cancelButton->setIcon(removeIcon);
              m_cancelButton->setToolTip(tr("Remove from list"));
          }
      }