[Qt-interest] Paint QWebView to a QImage

[Gilles Valette]

Message de Richard Hosking <richard at hovis.net>:

> Many thanks for the advice.  The repaintRequested approach seems to
> be the ideal method for me.
>
> I have implemented this, but I am getting Painter errors:-
>
> "A paint device can only be painted by one painter at a time"
>
> ...when painting to the QImage upon each repaintRequested call.
> I suspect some concurrency issues here on my part!
>
> I have attached my very stripped down test code which highlights
> my issue.  What do I need to do to make this work?  Do I need to
> 'queue' the paint events myself so they do not overlap?
>
> Richard.

Hi,

A QImage has its own QPaintEngine. This code does not cause any error  
and writes "repaint" and "end repaint" several times to the console:

void QImageWebRendererTest::repaintRequested(const QRect &dirtyRect)
{
     qDebug("repaint");
     QPainter* imagePainter = p_qimage->paintEngine()->painter();
     //imagePainter->begin(p_qimage);
     p_qwebpage->mainFrame()->render(imagePainter, dirtyRect);
     //imagePainter->end();
     qDebug("end repaint");
}

Hope this helps,

Gilles