MobileRead Forums - View Single Post - Qt 5.6 removing QtWebKit and Calibre's plans?

kovidgoyal · 01-27-2016, 10:38 PM

Qt is going to keep WebKit around for the lifetime of Qt 5.x. They may or may not stop releasing it in 5.6 (I have seen conflicting info on that on the Qt and KDE mailing lists). But they will make a source code release of it available.

Qt (and indeed all calibre dependencies) is built from source in calibre in any case, so I plan to keep using it for the lifetime of Qt 5. Once Qt 6 arrives, I will takeover maintenance of Qt WebKit myself (just as I already maintain a fork of python 2.7 that builds with Visual Studio 2015).

In the long term I will of course gradually phase out Qt WebKit from calibre in favor of a mix of QWebEngine and the Chromium Embedded Framework. The problem is that in calibre Qt WebKit is used in far more sophisticated ways that WebEngine cannot replace. For example, as an automated headless browser and to render HTML to PDF.

I have a good deal of experience with QWebEngine (having written my own browser using it https://github.com/kovidgoyal/vise) and once a few outstanding bugs are fixed, it should be fairly easy to port the preview panel and viewer in calibre to web engine. I imagine the same is true for Sigil's preview panel (although I am not sure about your Book View mode, since I dont know the details of how it operates).

I suggest you continue using WebKit in the short to medium term and start thinking about porting Sigil to WebEngine after a few more releases in the Qt 5.x line (I'd say Qt 5.7), when WebEngine is more mature -- note that currently Qt has not even ported their own Qt Assistant application to WebEngine. I have to say I have been less than impressed with Qt's project management.

01-27-2016, 10:38 PM	#2
kovidgoyal creator of calibre Posts: 45,382 Karma: 27756918 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Qt is going to keep WebKit around for the lifetime of Qt 5.x. They may or may not stop releasing it in 5.6 (I have seen conflicting info on that on the Qt and KDE mailing lists). But they will make a source code release of it available. Qt (and indeed all calibre dependencies) is built from source in calibre in any case, so I plan to keep using it for the lifetime of Qt 5. Once Qt 6 arrives, I will takeover maintenance of Qt WebKit myself (just as I already maintain a fork of python 2.7 that builds with Visual Studio 2015). In the long term I will of course gradually phase out Qt WebKit from calibre in favor of a mix of QWebEngine and the Chromium Embedded Framework. The problem is that in calibre Qt WebKit is used in far more sophisticated ways that WebEngine cannot replace. For example, as an automated headless browser and to render HTML to PDF. I have a good deal of experience with QWebEngine (having written my own browser using it https://github.com/kovidgoyal/vise) and once a few outstanding bugs are fixed, it should be fairly easy to port the preview panel and viewer in calibre to web engine. I imagine the same is true for Sigil's preview panel (although I am not sure about your Book View mode, since I dont know the details of how it operates). I suggest you continue using WebKit in the short to medium term and start thinking about porting Sigil to WebEngine after a few more releases in the Qt 5.x line (I'd say Qt 5.7), when WebEngine is more mature -- note that currently Qt has not even ported their own Qt Assistant application to WebEngine. I have to say I have been less than impressed with Qt's project management. Last edited by kovidgoyal; 01-27-2016 at 10:46 PM.