Link underlining and descenders in PDF output

[davenz]

Hi all,

I want to change some aspects of PDF output for better quality. I've attached a screenshot that shows the problems.

descenders.png (41.37 KiB) Viewed 1398 times

1. The two highlighted areas show some strange underline formatting that surrounds the automatic numbering for tables and figures.


2. The default underline styling for links overwrites the glyph descenders (which looks messy and will be a problem for non-English languages.) I added this to my CSS for print output but it doesn't change the output:

Code: Select all

a {	
text-decoration-skip-ink: all;
}

(The font family is IBM Plex.)


Any clues about where to look to fix these two problems? I'm using Oxygen XML Editor 22.1.

Thanks,
Dave

[julien_lacour]

Hello Dave,

I tried to reproduce on my side using <oXygen/> XML Editor 22.1, build 2020100710 and I didn't succeed.
Here is my generated output. You will see the underlined text is ok on my side.

flowers.zip

(236.81 KiB) Downloaded 231 times

Could you indicate which template you are using for your transformation?
You could try to debug your CSS to see if somehow there is no CSS interfering with your customization or the default CSS style-sheets.

Regards,
Julien

[julien_lacour]

Hello Dave,

I forgot to ask you on which platform you are using Oxygen (Windows/Linux)?
Could you also indicate which PDF Reader you are using? (if it's not Acrobat Reader)

Regards,
Julien

[davenz]

Hi Julien,

Thanks for your reply and example. I'm using Oxygen XML Editor on Windows 10 and the latest version of Acrobat Reader DC.

The formatting that surrounds the table and figure text in your example is indeed fine. I'll dig into my stylesheets and see what could be causing this.

For the font underlining, I see in your example that the underline also overwrites the glyph descenders—you can see here that it overwrites the descender of the parentheses, p, and g:

descenders-2.png (24.23 KiB) Viewed 1350 times

Any clue how to fix this?

Thanks,
Dave

[julien_lacour]

Hello Dave,

Unfortunately this behavior is controlled by another CSS property called 'text-decoration-skip-ink' which is currently not supported by Apache FOP processor used inside Oxygen PDF Chemistry.
By default internet browsers have this property set to auto which means that underlined content will automatically skip glyphs descenders when underlining text (see specification: https://developer.mozilla.org/en-US/doc ... n-skip-ink).

I added a new feature request for analyzing if it is possible to reproduce this behavior on PDF outputs.
I will let you know as soon as we will have an answer to this problem.

Regards,
Julien

[davenz]

Hi Julien,

Thanks for looking into this -- good to know that the behavior is caused by something else upstream.

Cheers,
Dave