Spell checking support, installation and usage!

[mjeveritt]

Inspired by #6446 I thought perhaps we'd kick off a discussion topic/thread here rather than clutter the code side, to discuss usability and installation/etc !
There's also #6703 for Linux.

To repost from the original PR:

This is a minimal implementation of spell checking. Dictionaries must be saved as index.aff and index.dic in Dictionaries/ (next to Settings/). You can find dictionaries here (this collects some from various sources).

Features

• Toggle checking for all inputs in the settings
• Toggle checking for one input via context menu
• Apply suggestions via context menu (even when spellchecking is disabled)
• Works with undo/redo
• Emotes are ignored

Missing Features (might be cool to have this in the future)

• Currently, it's bring-your-own-dictionary. It would be cool if Chatterino could install dictionaries.
• Chatterino could try to access system dictionaries
• You can't switch the language per split right now.
• Custom dictionaries would be great (and "Add to dictionary").
• The spellchecker should be able to reload.

One thing I dislike is that QSyntaxHighlighter is synchronous, meaning it reruns every time a character is typed. Technically, you could hack around that by ignoring its requests to highlight a block and manually call rehighlight (at some timer tick, for example).

Closes #16.

[mjeveritt]

For some reason this doesn't seem to work on the two computers I've installed it on (both Ubuntu 22 LTS) . What is/should the troubleshooting process be?!
I don't see anything in the Settings/plugins(?) menu (as was mentioned) .. and nothing salient on the command-line when run from there.

Also, I tried putting the dictionary directly in my Chatterino/Settings/Dictionary folder, then realised perhaps it needed a sub-directory for the appropriate language, so created one for en-GB .. is this correct?!

[Nerixyz]

The Ubuntu builds don't have the spell checker enabled (it's a build option off-by-default). I suppose we could enable it for 24.04?

[mjeveritt]

oh, could you gate it with a run-time option perhaps?
What would it take for me to run a manual build?!

[pajlada]

The intention is to make this a run-time option instead yeah, but during initial development it helps for us to provide the feature without forcing users to update their build setup.
For now, you could build your own build, or make a PR with a CI update to build the 24.04 .deb file with spell checking (might require an update to the Chatterino/docker repo too)

[mjeveritt]

That's ok .. I've taken a quick look at the Docker container setup, and will see how far I can get this weekend perhaps! there are a few things that I need to port/set-up/update in this arena, so I'm sure I can refresh myself what's needed !

[jupjohn]

With spell checking being the third entry in the 2.5.5 changelog (as of beta 1,) I think it's worth adding an entry in the wiki on how to bring-your-own-dictionary. I imagine there will be at least one "how do I add spell checking" question in the discord, so might as well beat them to it.