page x of y using QPrinter - c++

Question

im generating a pdf file from html code using qt:
QTextDocument *document = new QTextDocument();
document->setHtml(htmlContent);
QPrinter printer(QPrinter::HighResolution);
printer.setPageSize(QPrinter::A4);
printer.setOutputFormat(QPrinter::PdfFormat);
printer.setOutputFileName("filename.pdf");
document->print(printer);
Is it possible to have the page information "Page X of Y" instead of only the page number? If yes, how?

Answer 1

The solution I propose is based on this code. I have added the necessary support for HighResolution
static const int textMargins = 12; // in millimeters
static const int borderMargins = 10; // in millimeters
static double mmToPixels(QPrinter& printer, int mm)
{
return mm * 0.039370147 * printer.resolution();
}
static void paintPage(int pageNumber, int pageCount,
QPainter* painter, QTextDocument* doc,
const QRectF& textRect, qreal footerHeight)
{
painter->save();
// textPageRect is the rectangle in the coordinate system of the QTextDocument, in pixels,
// and starting at (0,0) for the first page. Second page is at y=doc->pageSize().height().
const QRectF textPageRect(0, pageNumber * doc->pageSize().height(), doc->pageSize().width(), doc->pageSize().height());
// Clip the drawing so that the text of the other pages doesn't appear in the margins
painter->setClipRect(textRect);
// Translate so that 0,0 is now the page corner
painter->translate(0, -textPageRect.top());
// Translate so that 0,0 is the text rect corner
painter->translate(textRect.left(), textRect.top());
doc->drawContents(painter);
painter->restore();
QRectF footerRect = textRect;
footerRect.setTop(textRect.bottom());
footerRect.setHeight(footerHeight);
painter->drawText(footerRect, Qt::AlignVCenter | Qt::AlignRight, QObject::tr("Page %1 of %2").arg(pageNumber+1).arg(pageCount));
}
static void printDocument(QPrinter& printer, QTextDocument* doc)
{
QPainter painter( &printer );
doc->documentLayout()->setPaintDevice(&printer);
doc->setPageSize(printer.pageRect().size());
QSizeF pageSize = printer.pageRect().size(); // page size in pixels
// Calculate the rectangle where to lay out the text
const double tm = mmToPixels(printer, textMargins);
const qreal footerHeight = painter.fontMetrics().height();
const QRectF textRect(tm, tm, pageSize.width() - 2 * tm, pageSize.height() - 2 * tm - footerHeight);
doc->setPageSize(textRect.size());
const int pageCount = doc->pageCount();
bool firstPage = true;
for (int pageIndex = 0; pageIndex < pageCount; ++pageIndex) {
if (!firstPage)
printer.newPage();
paintPage(pageIndex, pageCount, &painter, doc, textRect, footerHeight );
firstPage = false;
}
}
Example:
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QTextDocument *document = new QTextDocument();
QTextCursor cursor(document);
QTextBlockFormat blockFormat;
for(int i=0; i < 10; i++){
cursor.insertBlock(blockFormat);
cursor.insertHtml(QString("<h1>This is the %1 page</h1>").arg(i+1));
blockFormat.setPageBreakPolicy(QTextFormat::PageBreak_AlwaysBefore);
}
QPrinter printer(QPrinter::HighResolution);
printer.setPageSize(QPrinter::A4);
printer.setOutputFormat(QPrinter::PdfFormat);
printer.setOutputFileName("filename.pdf");;
printDocument(printer, document);
return app.exec();
}

Answer 2

The above Is a good solution but will break your QTextDocument object if you work with it after the print. I have a QTextDocument that is a member of a dialog and when the calling function that provided the Printer (paintDevice) loses scope it crashes the document.
I suggest getting a poiner of the current paintDevice at the start of the function then restoring it at the end.
static void printDocument(QPrinter& printer, QTextDocument* doc)
{
QPaintDevice * oldDevice=doc->documentLayout()->paintDevice();
doc->documentLayout()->setPaintDevice(&printer);
doc->documentLayout()->setPaintDevice(oldDevice);
}