[Development] Making QWebEngineView work inside a QGraphicsView

[Dimitar Asenov]

Hi all,

Now that QWebKit is no longer included with Qt, I need a new way of 
using a web renderer inside a QGraphicsView. Previously I used 
QGraphicsWebView but the official porting guide pretty much says that 
QGraphicsWebView will have no WebEngine-based equivalent:
http://doc.qt.io/qt-5/qtwebenginewidgets-qtwebkitportingguide.html

So I tried using QGraphicsProxyWidget as a way to get QWebEngineView in 
a QGraphicsView, expecting a total failure (the porting doc made it 
sound highly unlikely that this might work). To my surprise the 
QWebEngineView was correctly rendered inside the QGraphicsView and even 
transformations like scaling seem to work. The one problem seems to be 
that the QGraphicsView is not repainted when the image displayed by the 
proxied QWebEngineView changes. For example if I click on a link, 
nothing changes on the screen (it appears frozen). However, if I update 
the QGraphicsView (e.g. by scrolling/resizing it) the new content of the 
QWebEngineView is again displayed.

So this setup is almost working properly. Does anyone have an idea of a 
way to get the QGraphicsProxyWidget to automatically repaint itself when 
the content of the QWebEngineView changes?

Cheers,
Dimitar