Print/save QTextDocument to Image

[apaczenko1993]

Hello all
Fast question, does anybody know how save QTextDcument as a PNG file? I know that I can print QTextDcument as a pdf file but i need a PNG Image file. BR Michał

[Christian Ehrlicher]

Use QTextDocument::render() and render it into a QImage.

[apaczenko1993]

Maybe you have some examples how to use it??

[SGaist]

Hi,

QImage image;
QPainter painter(&image);
myDocument.drawContents(&painter);
image.save("myDocumentImage.png");

[edit: Fixed code SGaist]

[apaczenko1993]

Hi, there is no draw function in QTextDocument class :(

[J.Hilk]

@apaczenko1993 its's most definitely there:
https://doc.qt.io/qt-6/qabstracttextdocumentlayout.html#draw

but it seems to require a PaintContext object, as. ti doesn't have a default argument

[JonB]

@J-Hilk , @SGaist
You refer to QAbstractTextDocumentLayout. However, the OP is using QTextDocument, that does not inherit from QAbstractTextDocumentLayout and has no such method. Doesn't he need to go via QAbstractTextDocumentLayout *QTextDocument::documentLayout() const?

[SGaist]

@JonB Wrong method, I was thinking about QTextDocument::drawContents. Code updated.

[J.Hilk]

@JonB I actually got to that documentation entry via QTextDocument, I swear, but I can't reproduce it now 🤷‍♂️

I only end up with drawContext, @SGaist mentioned

[JonB]

@J-Hilk said in Print/save QTextDocument to Image:

I swear, but I can't reproduce it now 🤷‍♂️

An hour has gone by now ;-)

[apaczenko1993]

Ok, now i can print document into png file but the resolution is very low

QImage image (doc->size().width(), doc->size().height(), QImage::Format_ARGB32_Premultiplied);

    image.fill(Qt::transparent);
    QPainter painter(&image);
    doc->drawContents(&painter);
    painter.end();
    image.save("Test.png");

How can I set higher resolution of this picture? At this moment the resolution of document is 997x566

[ChrisW67]

What page size have you set on the QTextDocument?

[apaczenko1993]

Okey, after setting pageSize and scaling in Qpainter the document looks very well :) thanks for help