Support Multiline Indentation on Chrome and Safari

[StevenEWright]

Originally from: antonmedv#100

This PR partially addresses antonmedv#97 by providing opt-in support for multiline indentation in non-Firefox browsers.

By default, the current behavior (and codepaths) are the same as before. To opt-in to the new feature, users must enable a new option (multilineIndentation), as demonstrated in the updated Index.html

  const jar = CodeJar(editor, withLineNumbers(highlight), {multilineIndentation: true, tab: '  '})

I believe it would be possible to support Firefox, and I'm happy to collaborate with someone on this PR if they'd like to see support added for that initially.

[ben519]

Impeccable timing. I just came looking for this feature!

[StevenEWright]

@ben519 I am working on a project where this component is a key feature. I hope to be doing a lot of work on this over time. If you have any thoughts / comments / etc, I'd love to hear.

[ben519]

I'm also working on a project where I would love a few small additional features to CodeJar. I may be willing to sponsor some of your work if it's going to get merged into the main project.

[StevenEWright]

@ben519 No need to sponsor :) But that's a generous thought.

I don't think this work will ever be merged into the main project. My impression is that the main branch is keen to maintain a pretty minimalist set of features. For example, the maintainer pulled first party support for line numbers, has been pulling support for auto-close-brackets, doesn't seem keen to facilitate getting multi-line indentation-with-tab in, doesn't want to support no-wrap, etc.

I can understand the desire for a bare-bones editor, and I see value in that - and I can understand wanting to extern things like line numbers by supporting some composable design - but, in general, I don't think he's going to support sufficient composability to achieve all of the features I need in purely composable ways - and I have an interest in going quite a bit further - by, for example, recycling dom elements while scrolling so that my users don't have problems when they try to delete/cut 100s of lines of text.

So, yeah, my plan is to maintain a branch that pulls in useful features from upstream where it can, but otherwise steams along on its own more full-featured path.

[ben519]

Gotcha. Well, I commend your effort. I'm all about keeping things light, simple, and bug free. Just to give you an idea of what I'm looking for...

1. Everything that comes with a basic text editor should just work. I.e. copy, paste, undo, redo, tab indent (including when a block of text is highlighted), etc.
2. Auto-closing of quotes, brackets, parentheses, etc. is great, but I wish I could choose which characters had this feature. It's annoying when single quotes get "auto closed" because I mostly use them for english contractions like "the dog's bowl".
3. The more I play with CodeJar, the more I realize how important auto-indentation is to my normal coding experience. If you could nail this, that'd be wonderful.

I think I need to mess around with Monaco Editor and CodeMirror. They seem way more bloated than what I need, but the support behind them is a major benefit.

[StevenEWright]

Don't forget Ace.

I evaluated all of them for myself but RTL support is critical for me and I didn't feel it was a sufficient priority for any of those. Even if i was willing to figure out their codebases to contribute I didn't feel it was something they would care enough about preventing from breaking. To wit i believe codemirror supported it in an old version but no longer? I forget.

[StevenEWright]

@ben519 Please see: @kullna/editor