Notes: Some scenarios where positions can be lost

[t-hamano]

Description

Related to #72836

While reviewing #73046, I noticed that note positions get lost in more and more scenarios, so we need some kind of fundamental solution approach.

Step-by-step reproduction instructions

Below are the issues I discovered.

Block transformation

• Transform a block with notes into another block.

transform-block.mp4

Hidden block

• Hide a block with notes.
• Deselect the block and select the block again.

hidden-block.mp4

Detach pattern

• Create a synced pattern from a block with notes.
• Disconnect the pattern.

disconnect-pattern.mp4

[Vrishabhsk]

Hi @t-hamano 👋

• I was able to only replicate the issue in the hidden block scenario.
• Raised a PR for the fix : Fix : Note position #76344

Let me know your thoughts on this. Thanks

[Mamaduka]

I was re-testing this with #77433 and can confirm that it fixes 2 out of 3 issues. The "hidden blocks" issue remains, but it would require a different approach; we can't fix the position of the block element, which isn't rendered in the canvas.

The fix from #76344 won't work. The notes can be and are positioned offscreen with a negative y. It's when working on large content with many notes. @Vrishabhsk, I think we can close that PR.

@t-hamano, do you mind updating the title/description after #77433 is merged? Then we can try to find a solution for the hidden blocks.

[Mamaduka]

Here's a short description regarding why notes for Hidden Blocks are "broken".

Why?

A floating note requires a block element to calculate its relative position in the sidebar; when the block is hidden, its element isn't rendered. Threads that do not contain a block element are excluded from the calculations and end up misaligned.

What's the desired resolution, considering the listed limitations?

cc @ramonjd

[ramonjd]

What's the desired resolution, considering the listed limitations?

I've been banging on about this for a while, and I'm still convinced of this single proposition:

hidden blocks should be visible in the editor, with a visual/accessible indication that they are hidden. It should be then possible to toggle them all on/off to "preview" the effect.

There hasn't been consensus on this view, which is fine, but the more we run into UX cul-de-sacs such as this one, the more, I feel, it makes sense.

See:

• Enhance Block Visibility: Introduce 'Show Hidden Blocks as Ghost' fea… #74150
• Hidden blocks should still be visible in the editor #73838