First steps with QWebEngine

Needing to kill some time this evening while my wife worked on her website, I sat down and began the process of converting Cobro from QWebView, QWebPage, QWebSettings to use their modern but more verbose counterparts, QWebEngineView, QWebEnginePage and QWebEngineSettings. Things look good but as usual there are some issues.

Thanks to my splendidly modular and well-organized coding style, there is really only one object affected in the whole program, a QWebView derived class. I changed its parent class from QWebView to QWebEngineView, and then began going through all the self-initializing lines I had used to set up the QWebView.

Many of them had direct equivalents. For example, self.page() returns the underlying QWebEnginePage just as it previously returned the QWebPage. One still uses self.settings().setAttribute(something, True/False) for setting properties. However, I quickly discovered that several of the settable properties of QWebSettings are not available in QWebEngineSettings.

In particular, there is no JavaEnabled, no PluginsEnabled, and no PrivateBrowsingEnabled. I put a query about these three on the qt forum. It seems strange they would go to some trouble to make the new API compatible with the old, and yet leave out settings, and fairly significant settings at that.

Also my app implements a custom context menu. In it, I use the following to check to see if the thing that was right-clicked upon is a URL. Call self.page().currentFrame() to access the QWebFrame in which the right click occurred. Ask that for hitTestContent(QPoint) to find out what was under the point of the mouse event. If it is a URL, then I can access the text of that URL, and offer the user to open it in the default browser. This is very useful; Cobro is not a full-function browser, and if there is something on a comic page besides the comic, it is handy to be able to jump to a real browser.

Unfortunately it does not appear that QWebEnginePage offers access to the current frame. And there is no QWebEngineFrame class. So although QWebEnginePage specifically documents that you can implement a custom context menu, it is not clear how one can find out what was under the right-click. I also posted a query about this in the qt forum.

However, I just commented out all the parts that I couldn't immediately translate, and ran the app, and up it came. And displayed a comic very nicely. The progress bar signals worked, the titleChanged signal worked. So that was a useful couple of hours.