On 2013-03-25, Andras Becsi <abe...@webkit.org> wrote:
On 25 March 2013 11:28, Olivier Tilloy <oliv...@tilloy.net
<mailto:oliv...@tilloy.net>> wrote:
Hi all,
I have been observing that the rendering of web pages in a QML
browser seems to happen in one go at the very end of the loading
process, as opposed to other webkit browsers (such as chromium).
In my tests, I deleted the cache and I intentionally slowed down the
network interface to better observe when rendering starts to happen.
I’ve mostly experimented with http://nytimes.com, which is a rather
heavy page. I’m running those tests on an x86 desktop machine, but
the same results are observed on mobile hardware (armhf).
With the QML MiniBrowser compiled from webkit trunk against QtWebKit
5.0, nothing is rendered until the page is fully loaded (i.e. the
webview remains completely blank until the progress bar reaches
completion).
Just quickly ran a test with MiniBrowser on my desktop and for me with a
clean cache even heavy pages like nytimes.com <http://nytimes.com> start
to render when the progress bar is at about 50% completion. Although
this probably varies depending on network and HW speed.
This is comparably similar behaviour as you would experience with Safari
on Mac.
Thanks for the heads-up! So this means my build of QtWebKit somehow is
to blame.
I’m using libqt5webkit5-qmlwebkitplugin
5.0.0-0ubuntu1~quantal1~test5~withdebug~gstabs~patches (from
https://launchpad.net/~canonical-qt5-edgers/+archive/qt5-proper) in
Ubuntu 12.10, which according to the source package is based off trunk
subversion revision 136242.
I’ll test a full build from trunk to see if that makes any difference.
With chromium (25.0.1364.160-0ubuntu0.12.10.__1), rendering is
clearly progressive, with elements of the page being displayed
before loading is complete (and of course, some re-layout happening).
With Chromium the perceived page load / rendering speed is much faster
because the browser uses a variety of speculative optimization
techniques to speed up page loading. Among others these are resource
pre-fetching and page pre-rendering, which are implemented in the
browser [1] and depend on mouse-hover and usage heuristics.
Good to know. I was comparing to chromium because that’s what I had at
hand, but I’d be happy even without speculative optimization techniques,
if I can get pages to start rendering at ~ 50% loading completion, as
you’re observing.
Is this a known issue/feature? Are there some build options that I
can experiment with to tweak this?
As far as I know we have only access to DNS-prefetching with WebKit2
QtWebKit, which is enabled by default.
Thanks for the info!
Olivier
_______________________________________________
webkit-qt mailing list
webkit-qt@lists.webkit.org
https://lists.webkit.org/mailman/listinfo/webkit-qt
