downloadwidget.cpp Example File

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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"));
      }
  }