Add progress indicator for rendering of pages

Hello,

Have you compared the rendering speed with Okular? Evince uses Poppler's glib backend whereas qpdfview and Okular use the Qt backend. Both backends use different rendering devices, glib's is based on Cairo whereas Qt's is using Poppler's internal Splash output device. They have different performance characteristics and sometimes the Cairo backend is faster for specific files.

Also, using the current Poppler 0.22, I can't confirm the several-seconds rendering times you describe for the linked document.

The cache size itself does not change the rendering speed, it just stores previous rendering results to prevent redoing the work later on.

Regards, Adam.

Hi!

No, I didn't compare the rendering speed with Okular, because I don't want to install kde libs.

Ubuntu 12.10 currently uses poppler 0.20.4-0ubuntu1.1. Maybe the new 0.22 version is rendering faster.

Anyway, have a look on this comparison between evince and qpdfview: https://www.wuala.com/sojusnik/performance/?key=9Ut52rg2J39G

And what do you think about implementing a loading indicator?

Kind regards!

Hello again,

Well, it is difficult to decide whether this is a problem in qpdfview or just the usual performance variations of Poppler's Cairo and Splash rendering backends without direct apple-to-apple comparisons... However, from my experiences, I'd say that the speed difference shown in your video is entirely within these variations.

Concerning a progress indicator, I made a preliminary implementation [1] and will discuss it with Alexander Volkov. But I feel that this very close to eye candy which I try to keep to a minimum. Of course it does serve a useful purpose, so I will think about it.

Regards, Adam.

[1] https://code.launchpad.net/~adamreichold/qpdfview/progress-indicator

Hello!

Well, is the aforementioned pdf rendered approximately at the same speed on your pc as it's shown in my video?
Nevertheless, it feels so slow to me in comparison to Evince, although it seems to be a limitation of the Splash rendering backend :/

Cheers!

Since the difference in rendering speed is - with high probability - connected to the different rendering backends, I repurposed this bug report to track the inclusion of a progress indicator for rendering pages.

I added a progress indicator, meaning the program will display the FDo "image-loading" icon while a page is still rendering and the FDo "image-missing" icon if rendering of the page failed. This IMHO less intrusive than a progress bar or spinner and still conveys useful information. I also added fallback SVG icons from the Tango icon theme.

Adam, is the aforementioned pdf rendered approximately at the same speed on your pc as it's shown in my video?

qpdfview is such a great reader, but it's so slow in comparison to evince :/ Even text only pdfs are sometimes rendered very slowly...

As I said earlier, it is rendered faster on my system, but this is quite a useless comparison since I use Poppler 0.22 at the moment and the difference in hardware is unknown. (Not that I have a very brawny machine, but this needs to be taken into account.)

The one only really useful benchmark I see is w.r.t. to other viewers using the Poppler's Qt frontend and hence the Splash renderer on your machine, i.e. trying Okular or maybe PdfViewer (also Qt-only).

Same problem here, hate to say that, but qpdfview has very slow rendering compared to evince.
Didn't try Okular, it has a lot of dependencies.

Hello again,

if you still feel that even with a current version of Poppler, the speed should be improved, you could try testing the branch linked to bug #1150832 adding an experimental plug-in based on MuPDF.

Best regards, Adam.