printhandler.cpp Example File

webenginewidgets/printme/printhandler.cpp

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  #include "printhandler.h"
  #include <QEventLoop>
  #include <QPrintDialog>
  #include <QPrinter>
  #include <QPainter>
  #include <QPrintPreviewDialog>
  #include <QWebEnginePage>

  PrintHandler::PrintHandler(QObject *parent)
      : QObject(parent)
  {

  }

  void PrintHandler::setPage(QWebEnginePage *page)
  {
      Q_ASSERT(!m_page);
      m_page = page;
      connect(m_page, &QWebEnginePage::printRequested, this, &PrintHandler::printPreview);
  }

  void PrintHandler::print()
  {
      QPrinter printer(QPrinter::HighResolution);
      QPrintDialog dialog(&printer, m_page->view());
      if (dialog.exec() != QDialog::Accepted)
          return;
      printDocument(&printer);
  }

  void PrintHandler::printDocument(QPrinter *printer)
  {
      QEventLoop loop;
      bool result;
      auto printPreview = [&](bool success) { result = success; loop.quit(); };
      m_page->print(printer, std::move(printPreview));
      loop.exec();
      if (!result) {
          QPainter painter;
          if (painter.begin(printer)) {
              QFont font = painter.font();
              font.setPixelSize(20);
              painter.setFont(font);
              painter.drawText(QPointF(10,25),
                               QStringLiteral("Could not generate print preview."));

              painter.end();
          }
      }
  }

  void PrintHandler::printPreview()
  {
      if (!m_page)
          return;
      if (m_inPrintPreview)
          return;
      m_inPrintPreview = true;
      QPrinter printer;
      printer.setResolution(300);
      QPrintPreviewDialog preview(&printer, m_page->view());
      connect(&preview, &QPrintPreviewDialog::paintRequested,
              this, &PrintHandler::printDocument);
      preview.exec();
      m_inPrintPreview = false;
  }