QPixmap: How to render?

[A Former User]

Hello,

i want to render a qt chart to a pixmap which i want to insert into a qtextdedit.

    QPixmap renderedPix;
    m_chartView->render(&renderedPix, QRectF(), QRect(), Qt::IgnoreAspectRatio);

    QPixmap renderedPix;
    m_chartView->render(&renderedPix);

Both code examples won't work.
And: How can i insert this rendered Pixmap into QTextEdit?

Thank you,
Henrik

[jsulm]

What does not work? How did you check?

To insert image see documentation (http://doc.qt.io/qt-5.7/qtextedit.html):

void TextEdit::insertFromMimeData( const QMimeData *source )
{
    if (source->hasImage())
    {
        QImage image = qvariant_cast<QImage>(source->imageData());
        QTextCursor cursor = this->textCursor();
        QTextDocument *document = this->document();
        document->addResource(QTextDocument::ImageResource, QUrl("image"), image);
        cursor.insertImage("image");
    }
}

[raven-worx]

@HenrikSt. said:

Both code examples won't work.

you need to create the pixmap with a given size. Currently you are creating a null-pixmap.

And: How can i insert this rendered Pixmap into QTextEdit?

QUrl url("mydata://image1");
QTextDocument *document = textEdit->document();
document->addResource(QTextDocument::ImageResource, url, QVariant::fromValue<QPixmap>(pix));

QTextCursor cursor = textEdit->textCursor();
QTextImageFormat imageFormat;
imageFormat.setWidth( image.width() );
imageFormat.setHeight( image.height() );
imageFormat.setName( url.toString() );
cursor.insertImage(imageFormat);

// or alternatively:
QTextDocumentFragment fragment = QTextDocumentFragment::fromHtml("<img src='mydata://image1'>");
cursor.insertFragment(fragment);

[jsulm]

@HenrikSt. Maybe you should resize the QPixmap like in the example in the documentation (http://doc.qt.io/qt-5/qwidget.html#render):

QPixmap pixmap(m_chartView->size());
m_chartView->render(&pixmap);

[A Former User]

@raven-worx
Thanks for your answer.

How can create a pixmap with a given size?
Can you make an example?

Thanks :)

[Joel Bodenmann]

The QPixmap class has a constructor that takes a QSize parameter and therefore allows you to create a pixmap of a given size. That is what @jsulm is doing in the first line of his last code example. Documentation.