Add vertical justification

[TonioGela]

First of all thanks, I've installed all the betas of Kobalt on my clara 2e and I'm loving so much every single feature.
I know this request/idea might appear strange, but I think it might be worth a try.

In general when we set the text as justified and we also set the horizontal margin to be i.e. 12 pixel we do expect that:

1. words will begin rendering 12px from the left border
2. the remaining space will be filled with enough words to fit the line leaving at least 12 px free for the right margin plus the minimum space that is required to space the words
3. if there's more than 12 px left because the next word in the line will render to more than 12 px in width then the (remaining free space minus 12 px) will be distributed between the word gaps and the last word on that line will get render so that it will touch the right margin.

Well, something that bugs me is that step 3 vertically never happens and despite the first line will be at exactly 12 px from the top, most of the times the last row will be more than 12 px from the bottom, usually between 12px and (12px + row height + row separator height)

I get this is a super niche feature, but it will make Kobalt the only text reader that I know of practically perfect. I don't know anything about how this or other text renderer are built, but I'd love to help out. For what is worth, what I have in mind is a vertical version of the justify-content: space-between; CSS rule.

[nicoverbruggen]

This is a difficult one but I'm going to task an agent to look into it. It's a similar request to #52.

[TonioGela]

That works greatly! Thanks immensely, my inner OCD beast is now quiet. I felt like donating from that dev builds page 😇

Vertical.Justification.mp4

[nicoverbruggen]

Wow, thanks! Great to see it's working as expected 😄

[TonioGela]

I guess we'll see it stable in rev5, right? In any case I'll keep this build installed till you'll merge to stable.

[nicoverbruggen]

Yes, this should land in beta 5 next weekend.

[MushyDots]

If you're on 4.x, you can find a test build here: https://kobalt-dev.nicoverbruggen.be/test-builds/669922a67d1b244bc27fc5d66a8b5f7b91693dbd45082fcf (if you're not, let me know)

Let me know if that works how you'd expect it to.

I just tried this build out. I love it! I agree with @TonioGela; it really tickles my brain just right.

[Oakwine]

TonioGela, I'm here from the closed #52. Turning on widow and orphan control exacerbates this spacing issue, so you might want to turn that off if blank space on the bottom of the page bothers you.

[Oakwine]

How would this work with embedded graphics? Would this left-side page get stretched out?

[nicoverbruggen]

I'd need to take a look. For the centering option the text needs to occupy >90% of the pixels of the area text would normally fill, but I'm not sure what happens with the line height. Love to see landscape in use, btw.

[nicoverbruggen]

OK, so here's the thing: the implementation on develop currently rejects image-containing lines from adjustment. If any content on a page is unsuitable, it disables adjustment for the whole page. So, this should not change.