Overriding Ebook Stylesheet

[Archuleta]

I've recently purchased a Kobo Glo HD after using the desktop Kobo app for a while to read some purchased ebooks. The desktop app appears to ignore a lot of book-specific formatting in order to display pages nicely within the window, but I was surprised to find that the Glo HD does not do this. Instead, my purchased ebooks have different default margins and line-spacing which cannot be changed (the sliders are disabled for Japanese books), and some English books ignore my font and justification selections. I'm disappointed by all this, because I thought that it would render the books like the desktop app does, and seeing as the sole purpose of the device is to render ebook pages, I had thought that it would do a better job. Reading through other forum posts, I believe that the formatting can be changed manually by DeDRMing books, importing them into Calibre, manually adjusting the files, and then sideloading the files onto the device. However, this adds a bunch of extra steps between buying a book and being able to read it, and moreover I can't get Calibre to work properly with vertical Japanese text. Instead of going through all of this, is it possible to put a single stylesheet on the device that will override book-specific styles or something like that?

Thanks for your help!

[anavin]

I don't know how to do it without dedrm. On the other hand, I know there are some solutions for dedrm / sideload books:

1. There's a feature in calibre's Kobo driver that you can put a file called kobo_extra.css in the device's root directory and calibre would embed its content during sending to the device, see here.

2. About the vertical text, it's only supported by the Access engine which would only work on something called "kepub." With a plugin called "KoboTouchExtended", calibre can convert your books to kepub on the fly when sending them to your device.

3. And about margin/linespace of Japanese books, you can edit the books' locale (or just the locale in the onboard database, KoboReader.sqlite) to anything not Japanese to unlock the scrollbars, see here.

[GeoffR]

There are separate device stylesheets for ePub and KePub books, but they are dynamic, created in memory from fragments with values that depend on which options you have selected on the device.

Currently the only way to change the device stylesheets is by patching the firmware. In earlier firmware versions there was a user stylesheet named kepub-book.css that was used for KePub books, but that feature was removed some time back (somewhere around firmware 3.2.0 I think.)

If you have a book where you can't change the font face, then I think that must be an ePub book. From what I know there is no way the publisher can prevent the font being changed in a KePub book. If you sideload the book in KePub format instead then I think you will get something a bit closer to what you see in the Kobo app.

[frostschutz]

I can't get Calibre to work properly with vertical Japanese text.

it doesn't have to be calibre, other epub editors of your choice would work too... (regardless whether they are able to display a preview, its the source code that matters... viewing it can be done on the reader itself)

for [vertical] japanese text, kepub is your only option anyhow. (if it worked in regular epub that would be news to me). so far I opted to edit the css in the book directly (e.g. to make furigana grey instead of black so I try to read kanji first). actually I also had to edit the HTML since the kobo does not handle furigana too well in the first place (prevents dictionary lookups, which could work better for japanese... oh well).

for more external stylesheet stuff you might have to switch to the alternate readers (koreader, coolreader), not sure if they have japanese support