HELP: svg file in Sigil for epub on Kobo

[KevinH]

Yes the IDPF use the word "obsolete" to describe epub2, but "deprecated" is more correct since it is still used by older readers.

https://idpf.org/epub/201

[philm]

Originally Posted by RbnJrg

Readium, Bibi and EpubJS.

Nnoe of them work on Ubuntu 22:

ImportError: cannot import name 'QtWebEngineCore' from 'PyQt5' (/usr/lib/python3/dist-packages/PyQt5/__init__.py)

Despite installing QTWebEngineCore (only avail package is python3-pyside2.qtwebenginecore)

[KevinH]

You are missing pieces. You need to install pyqt5.

Here is a link I found by a websearch that explains how to get the qtwebengine piece of pyqt5. And something similar should work on the main pyqt5 itself.

https://installati.one/ubuntu/22.04/...5.qtwebengine/

There are probably better links but that was the first I found.

Update:

Try the following:

sudo apt-get install python3-pyqt5
sudo apt-get install python3-pyqt5.qtwebengine

Both macOS and Windows builds of Sigil come with these installed. I truly have no idea why various Linux distributions treat these packages as "optional" when full plugin support is part of Sigil, has been for a long time, and will continue to be.

[philm]

Thank you @KevinH
Weird because synaptic said it was installed and apt-install still installed it. Maybe I needed a force re-install.
Never mind, they are working now but not displaying my epub, and Foliate too.
I'll check format and content tomorrow.

[philm]

Okay,
So far, I found that:
- <img> doesn't work in Sigil readers (Bibi, EPUBJS, Readium), but embedding it in <svg> works. Very surprising
- tables and SVG are not implemented in SumatraPDF, others?
- height in <svg> looks like it means "visible height of the image relative to its width". A 1920x1080 at 100% for width and height will be a white square with the image in the center, while height="56%" (1080/1920) is enough to fully display it. It's not like HTML.

Is there any other mine I should be aware of?

[RbnJrg]

Originally Posted by philm

Okay,
So far, I found that:
- <img> doesn't work in Sigil readers (Bibi, EPUBJS, Readium), but embedding it in <svg> works. Very surprising

You must be doing something wrong. Watch the newEpub3.epub I attach where I employ the <img> tag to display the svg image. In the first page you can see the image not centered vertically and in the second page you'll see the image vertically center to mimic a svg wrapper. And the epub is perfectly displayed on Readium, Bibi and EpubJS (in fact, is correctly displayed everywhere if the ereader supports epub3).

- tables and SVG are not implemented in SumatraPDF, others?

SumatraPDF? But you had said us that you were working under Linux and Sumatra is a Windows pdf reader. And Sumatra is not the best option to display epub.

- height in <svg> looks like it means "visible height of the image relative to its width". A 1920x1080 at 100% for width and height will be a white square with the image in the center, while height="56%" (1080/1920) is enough to fully display it. It's not like HTML.

Well, well, well. This is not a place to explain in deep how the "viewbox" property works. If you want to learn a bit about svg, you should read the following page:

https://jenkov.com/tutorials/svg/index.html

And regarding the viewbox property, read:

https://jenkov.com/tutorials/svg/svg...-view-box.html

[philm]

Thanks for following up, your doc and links RbnJrg!

SumatraPDF works under Linux with Wine, it's even a snap package: https://snapcraft.io/sumatrapdf
It's the only one I found that automatically reload the epub file when I save in Sigil so it can sit there while I work on Sigil.

I forgot to say, I'm working on epub 2 now, just to check what is working for old e-readers.
I expect my result to work in epub3

[RbnJrg]

Originally Posted by philm

I forgot to say, I'm working on epub 2 now, just to check what is working for old e-readers.

It also must work under epub2. Open the epub2 I attach in Readium, Bibi and EpubJS; the svg should display ok also in your linux.