[Okular-devel] Are CSS files in OEBPS folder of ePub ignored at all by Okular?

[insight.am at libero.it]

Hello,
I performed some tests on ePub format with Okular and it seems that the css 
files inside OEBPS folder are ignored, that is, they are not loaded.
I do not know if it is a bug or if the ePub generator lacks the functionality 
(although I was not able to find the code for that in Okular or libepub) so I 
do not want to bother anyone, I am just informing you.
I unzipped an ePub file, edited the css file with strange rules (for example 
background:green) and recompressed it, but Okular ignores the rules, while it 
obeys them if they are in the source code:
mTextDocument->setDefaultStyleSheet("div {background: green;}");
(converter.cpp)
When an ePub is unzipped and an html section is opened with a browser, the css 
is loaded because the browser is able to access the folder, as happens for 
images. When an html file is extracted from the zip (epub) the css is not 
automatically loaded because the application should mount the zip like fusezip 
does, but I do not even know if QTextDocument would act like a browser; 
however, I think Okular just extracts the resources from the zip. 
I see that images are loaded as resources so css files can be loaded too, 
merged, and passed to setDefaultStyleSheet(). Warning: this makes sense if css 
files are intended to be the same for all sections (if I am not wrong nothing 
prevents some sections to have different css files, that could be conflicting 
if merged). However, I think usually there is one css file only or, when more, 
they are intended to be global. 
A reset css file on the top of them (like Eric Meyer's one or similar)  could 
be a good idea too. And then also other smart css rules could be added to 
obtain the best results in pagination, although the max-width and max-height 
rules I tested to avoid image overflowing seem not to be working (but other css 
rules do have effect, like  background:green).
I think css is very important because ePubs can yield poor renderings or 
strange results if css is ignored and it is what I experienced with some ebooks 
of mine with Okular.
Best Regards
Angelo