[Development] Assistant WebKit/WebEngine support

[André Pönitz]

On Mon, Jun 24, 2019 at 04:37:16PM +0300, Konstantin Tokarev wrote:
> > I have two more numbers to add: Compressed (7z) the download size would
> > be around ~44 MB. I measured on Windows with a Qt Creator built with
> > WebEngine support and surfed a little through the docs. The memory
> > consumption of the web engine process weighed in between 14-20 MB of RAM.
> >
> > So it looks like this AFAICS:
> >
> >      * We would be adding 145 MB of additional disk usage
> >
> >      * We would add ~44 MB to the download size of Qt Creator
> >
> >      * We would eat ~14-20 MB of additional RAM (not quite fair though,
> > as we'd have to subtract the QTextDocument memory usage for a diff).
> 
> For comparison, numbers for QtWebKit are: 84 MB of disk space (of which
> 26 MB is taken by ICU data), and 20 MB when compressed to 7z archive.
> I didn't measure RAM consumption, but I'm sure it won't take more than
> you've measured.
> 
> This is full build with all features enabled; it's possible to make reduced
> build without multimedia support, JavaScript JIT and other features not needed
> for help browser.

I actually tried that a while ago (i.e. clone Qt Webkit and throw out
everything that's not needed to display Qt's help) when the shift to
WebEngine was looming.

It worked up to a certain degree nicely in the build system by
de-selecting options, than quite a bit more by actually removing code.
Getting rid of all of JS was not obviously possible.

The result was ok-ish size-wise (and for me definitely preferable over
WebEngine) but the question is where to put to cut. In some setups
("Want to see DevDays videos") even cutting multimedia plugins won't be
accepted by everyone. I.e. the "need" for a "full browser" is likely
to always exist, and that's currently served by "use external help".

Andre'