I can't figure out how to post a topic without using a mouse.
My suggestion would be to support tabbing out of the textbox.
(I see that turning off visual editing seems to work.)
There is a request since a while to have a shortcut to post (basically Ctrl+Enter).
Some work will be done on Structured Discussion front end soon, and that shortcut may be part of it. The project definition is a work in progress.
I suspect the claim that it's not possible to "tab" out of the text box. I post this comment by tabbing to the "Reply" button and hitting the "Enter" key.
I missed the initial response.
@Trizek (WMF), this task is one solution, but as @Kaartic says, a more general solution is to "tab" out of the textbox. This is impossible to do when the textbox is in "visual editing" mode.
Though I didn't imply that "tab" would be a general solution, it really might be ;-) (Yeah, I forgot about the "visual editor" when I commented, sorry.)
That's likely because VisualEditor uses the "Tab" key for other functionality. Indeed, on an average editor the tab key should tab text, not jump from one menu / button to another.
A better idea is probably to add general keyboard accelerators see (https://www.mediawiki.org/w/index.php?title=Topic:U3waidy55yn309t9&action=history). Operating systems have used these for years (decades ?), and they are pretty straight forward. Tabbing on the other hand can be rather tedious if the interface has too many items / options.
I don't think VE uses Tab for anything except when you're editing a table. It seems they are wantedly suppressing the "Tab" presses inside the editor to avoid losing focus of the editor.
https://gerrit.wikimedia.org/r/#/c/255452/
Though their rationale might have worked at that time, it doesn't seem to with the usage of VisualEditor in StructedDiscussions (aka Flow).
VE does use the tab key to do what the tab key was actually designed for (indenting) and navigating. For example, the bullets below were indented (and can be unindented) an extra time using TAB:
It also uses tabs for navigating tables, and to create new rows. It would be even more unexpected if someone clicks tabs and it suddenly jumps to another interface item rather than the next table cell. Which happens in the "pre-formatting" dialog.
It just so happens that html formats indents differently, but it would be quite reasonable to expect the tab key to also work inside the pre tag input for example.
Oh, it also uses it in various code editors (graph, map, <syntaxhighlight>, etc).
If I am useing the tab key in the source editor on flow ("2017 wikitext editor"), I can't get out. It would be nice to have the tab key used to navigate normaly when useing a flow page. But if the whole page is edited (as in an article, this is not needed, and it's more comfortable to use the tab key for indent/oudent, tabing in tables ore other things like that but in a single textbox it should work to tab out to help people useing screenreaders or on computers without mouse.