This is because the button is implemented as a checkbox and pressing "Enter" with a focused checkbox generally doesn't toggle it, however, pressing "Space" does. Jamie, do you know if this is the intended behaviour for checkboxes ? If so, should this bug be fixed ?

(In reply to Tim Nguyen :ntim from comment #1)

This is because the button is implemented as a checkbox

That's how it's implemented, but is that how it looks?

and pressing "Enter" with a focused checkbox generally doesn't toggle it, however, pressing "Space" does.

That's true.

Jamie, do you know if this is the intended behaviour for checkboxes?

Yes.

If so, should this bug be fixed ?

As above, I'm curious as to whether this "looks" like a checkbox. Also, I'm bothered by the fact that this checkbox changes its name when checked/unchecked. When you press Show password, the checkbox gets "checked", but the label also changes to "Hide password". Semantically, that's confusing; "Hide password" being checked might suggest the password is hidden, when in fact it is shown and "unchecking" it will show the password. I'd prefer it either didn't change the label or was a button instead of a checkbox.

It seems that this issue behaves differently on "Edit" and "Create New Login" mode.

• If the "Show/Hide password" button is focused and the "Enter" key is press while the "Edit" or "Create New Login" mode is open, it saves the changes made.

Attached a screen recording with this behavior.

That is an expected behaviour on the web… Enter submits forms

Mass removing [skyline] and [passwords:management] from about:logins bugs which are no longer useful.

UX notes/recommendation:
Hide/show password as a checkbox element is correct, and when in focus, as expected - spacebar reveals (or shows/hides) password. "Enter" does not change the state of the checkbox. As noted above by Jamie, the label should not change to "Hide password" when the checkbox changes state. The label should remain "Show password" and changes from "unchecked" to "checked".

In this use case, "enter" should not submit form elements when visual focus is on show/hide password checkbox. "Enter" should submit form when user has "save changes" button in focus.

OK, so to be clear, then the only thing to change in this bug is to remove the title changing with the checkbox click, but leave the current spacebar/enter key functionality as is.

(In reply to David Durst [:ddurst] from comment #7)

OK, so to be clear, then the only thing to change in this bug is to remove the title changing with the checkbox click, but leave the current spacebar/enter key functionality as is.

Correct. Thanks!

Jamie - just verifying... If the show/hide icon is in (visual) focus, and not the "Save Changes" button or the password form itself, does the user still expect the enter key to submit/save the form fields?

(In reply to katieC from comment #9)

Jamie - just verifying... If the show/hide icon is in (visual) focus, and not the "Save Changes" button or the password form itself, does the user still expect the enter key to submit/save the form fields?

Various UI tends to be inconsistent here. However, standard HTML forms in Firefox submit the form when you press enter even if a checkbox is focused. So, I would go with that.

(In reply to James Teh [:Jamie] from comment #10)

Various UI tends to be inconsistent here. However, standard HTML forms in Firefox submit the form when you press enter even if a checkbox is focused. So, I would go with that.

Thank you!

https://hg.mozilla.org/mozilla-central/rev/56535429a7fb

Verified on Nightly 73.0a1 (2019-12-29). The label now remains as "Show password" in both checked and unchecked states.