Keyboard shortcut to open the sticker picker

[andybalaam]

Inspired by the desire to reduce the pain of element-hq/element-web#20887 this adds a keyboard shortcut to open the sticker picker.

Notes for reviewer:

1. It was difficult to find a suitable key combination. I went for Ctrl-comma Ctrl-semicolon in the end, but suggestions welcome. (Ctrl-S=save, Ctrl-T=new tab, Ctrl-I=Italic, Ctrl-C=copy, Ctrl-K=search, Ctrl-E=toggle webcam, Ctrl-R=refresh)

2. I followed the pattern of KeyBindingAction.SelectPrevSendHistory in my code, so this shortcut only works when the composer is focussed. Ideally it would work from more places, but my brain is not working brilliantly today and I feared running out of time before I made this work. Suggestions of how to do it better would be welcome, or we might decide needing to focus in the composer is right and fine?

---

This PR currently has no changelog labels, so will not be included in changelogs.

A reviewer can add one of: T-Deprecation, T-Enhancement, T-Defect, T-Task to indicate what type of change this is, or add Type: [enhancement/defect/task] to the description and I'll add them for you.

Preview: https://pr7985--matrix-react-sdk.netlify.app
⚠️ Do you trust the author of this PR? Maybe this build will steal your keys or give you malware. Exercise caution. Use test accounts.

[t3chguy]

Given how scarce remaining handy shortcuts are (and how awful destroying someone's muscle memory is by changing them later), things have to pass by product

[andybalaam]

So, relevant Product person: any suggestions for keyboard shortcuts to open the sticker picker? See above: Ctrl+S, T, I, C, K, E, R are all gone, as is Ctrl+comma, which was my first attempt.

[andybalaam]

Ctrl+; (semicolon) appears to be free (CMD+; on Mac).

[t3chguy]

Ctrl+; (semicolon) appears to be free (CMD+; on Mac).

Worth also checking other messengers e.g slack, discord so we don't conflict with a different behaviour users may expect.

[jakewb-b]

Do we have a list of shortcuts anywhere? I feel like that would be useful.

If semi-colon is free then I'm happy using that. I agree that now we've hidden some often-used items in the composer, adding shortcuts for them is a worthwhile use of the remaining handy key combos.

[SimonBrandner]

Do we have a list of shortcuts anywhere? I feel like that would be useful.

Yes, press Ctrl + /

[t3chguy]

Do we have a list of shortcuts anywhere? I feel like that would be useful.

Yes, press Ctrl + /

Or Settings > Keyboard which is far more discoverable

[SimonBrandner]

Thanks!

[andybalaam]

Confirmed that Ctrl-; does nothing in Slack or Discord.

[andybalaam]

@jakewb-b if you are happy to go ahead, please could you tick the review?

[t3chguy]

LGTM otherwise

[HarHarLinks]

How will this work on a German QWERTZ keyboard? We need to press Shift+, to write ;.

Similarly, Ctrl+/ does already not work because / is actually Shift+7.

[andybalaam]

@HarHarLinks does Ctrl+Shift+; work? You can try this now at https://develop.element.io

[HarHarLinks]

@andybalaam It Ctrl+Shift+, does not work. Which I expected since Ctrl+Shift+7 has not been working for a long time either. I seem to remember however that it used to work at some point. Issue: element-hq/element-web#21067

[andybalaam]

@HarHarLinks I'm really sorry - that is very frustrating. I think the existing issue element-hq/element-web#21067 is the right place to deal with this.