Block autoformat could work in all kind of blocks

[Reinmar]

📝 Provide a description of the improvement

So, right now when you're in at the beginning of a heading 2 and type ### it is not going to change it to a heading 3. It's only possible to turn a paragraph into other types of blocks.

This means that you can't easily toggle between block types. Also, if you made a mistake, you need to get back to a paragraph (e.g. by undoing) and only then you can use autoformatting.

One example of an application where you can always switch between block types is Notion and I use this quite a lot. Especially when I'm changing heading levels (cause I'm reorganizing a document).

Another aspect is that currently you can only apply autoformatting to an empty block. We'd also like to apply formatting for blocks that have some content in it, as long as your cursor is at the beginning of the line.

Related issue:

• It should be possible to convert a heading into a list item and vice versa

cc @jodator @panr @oleq

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[jodator]

One example of an application where you can always switch between block types is Notion and I use this quite a lot. Especially when I'm changing heading levels (cause I'm reorganizing a document).

After using this app for some time I feel that this is the expected way of doing things. IIRC I just used this app this way (might be a hint from a tutorial). It feels natural. Even so, then when testing our implementation of block autoformat it felt weird in that regard.

ps.: This change shouldn't be a time consuming one.

[Reinmar]

We did a quick review of the block autoformat code and there are a couple of things that might be worth at least considering when working on this:

• Reading model element names from the schema.
• Naming.
• isTyping.
• Not limitting this to paragraph with just one child (e.g. inline widgets, soft breaks, etc.).
• Check if autoformat could use TextWatcher (refactor) #2400

[Reinmar]

One thing I noticed in Notion is that `1. ` will work in a paragraph but not in a heading. While `# ` will work everywhere. That even makes some sense, so we should be careful to not "overdo" here.

[mlewand]

Cleaned up the issue a bit (extracted #7517).

Also we need more elaboration on that:

• Reading model element names from the schema.
• Naming.
• isTyping.

Related issue:

• It should be possible to convert a heading into a list item and vice versa

[Reinmar]

• Reading model element names from the schema.

It's about https://github.com/ckeditor/ckeditor5/blob/b80c677/packages/ckeditor5-autoformat/src/autoformat.js#L120-L139. It'd be cleaner if we read the heading* element names from the schema. But it's a completely minor issue.

Naming

It's most likely about https://github.com/ckeditor/ckeditor5/blob/b80c677/packages/ckeditor5-autoformat/src/autoformat.js#L126. It's not a command value. Since we planned to review this code, it might be a good moment to clean up such issues. But it's again a minor issue.

isTyping

It's about using the isInput property (it was renamed from isTyping -> isInput) to check whether a current change should be treated as typing. That property was added quite recently so the autoformat feature which was implemented very early is using some other heuristic (probably, worse).

[mlewand]

We had a quick discussion regarding these changes today, and we made several minor adjustments.

One thing I noticed in Notion is that `1. ` will work in a paragraph but not in a heading. While `# ` will work everywhere. That even makes some sense, so we should be careful to not "overdo" here.

Wile mentioned Notion doesn't allow turning a list to a header, we decided to simplify things and not impose such limitations for now. Which means there is not going to be any map telling what block can be turned into what.

While doing this issue we could also do some refactoring here and there (e.g. #7366, there are also some misused variable names in the code).

However for now the refactoring should be limited, so we're not going to utilize text watcher / perform a full rewrite.

[Reinmar]

I noticed that you can't turn a heading into a list by typing `1. `. You can, however, by typung `* `. That makes a lot of sense. I was just trying to number the headings (as steps) and I was positively surprised that Notion devs predicted this case. It makes a lot of sense to me. (edit: extracted to #7569)