Block Editor: LinkControl: Add Submit button as action

[aduth]

Extracted from #19462
Related: #19570

This pull request seeks to add a new "Submit" button to be shown alongside instead of the existing "Reset" button in the new LinkControl component used by the Navigation and Buttons blocks.

Before	After

Original Before/After

Before	After

Rationale

It only really occurs to me now, but I'm not really sure what benefits this brings.

If I had to guess:

• It could make it visually clearer that this is a form to be submitted, whereas otherwise it relies on the user having knowledge that pressing Enter is an equally effective means to submit the form.
• According to the original commit 90f7b5d from Try the link control in the link format #19462, "When clicking Change on an existing link you should be able to modify and then resubmit the link without having to repeat your search over again.". It's not really clear to me what impact there is on this behavior in whether or not a Submit button is present, though this could have been more relevant prior to changes in the form submission behavior as in Block Editor: Handle LinkControl submission via form handler #19651 (cc @getdave).

Even if we decide not to move forward with adding a submit button, and depending on some decision out of #19570 as to whether the "Reset" button should be removed as well, the proposed changes could still be valuable in providing a more reliable computation of offsets for absolute positioning of the spinner and reset buttons.

Testing Instructions:

Verify that when editing a link in a Navigation or Buttons block, you should see a Submit button shown an activated as long as the input contains a valid link.

Check as well that issues raised in #19462 with the original implementation have been addressed:

• Try the link control in the link format #19462 (comment)
• Try the link control in the link format #19462 (comment)
• Navigation loader is over the return icon #19544

[shaunandrews]

It only really occurs to me now, but I'm not really sure what benefits this brings.

I couldn't have said it better myself. The only thing that comes to mind is that a visual submit button might be more obvious and accessible than using the return key to trigger the action.

I will say, having two actions within the input is probably too much. If we decide to add a submit button, then perhaps we should remove the reset button to keep the number of actions to one.

[aduth]

The only thing that comes to mind is that a visual submit button might be more obvious and accessible than using the return key to trigger the action.

Yeah, personally, I would prefer that anything which behaves like a form (takes a submission) would have some explicit Submit button somewhere. I also recognize that it's somewhat at odds with the otherwise minimalistic aesthetic of the field.

I will say, having two actions within the input is probably too much.

I mentioned in passing in the original comment, but #19570 could be very much relevant to this conversation. That is, f we decide that the "Reset" button should be removed, could it be reasonable then to keep the "Submit" button (i.e. swap out Reset for Submit).

[aduth]

The issue I opened at #20007 has relevance, since it explores what might be necessary to reintroduce a "Link Settings" button/toggle to the editing state of this component. That would be a third option, in addition to the existing "Submit" and "Reset" considerations. What I propose there is to remove "Reset" altogether, and go with "Submit" and "Settings". That's still two actions, but it is consistent with how this UI has existed up 'til now (the previous Gutenberg link UI and the link UI in the Classic Editor).

At the very least, to keep this moving, I might still like to implement replacing "Reset" with just "Submit", but including all of the CSS refactoring which should make it simpler to adjust these buttons in the future (adding, removing, or substituting).

[aduth]

I've rebased the branch to resolve conflicts, and per my previous comment, to change the purpose of the pull request to replace the "Reset" button with the Submit button. I've also altered the implementation slightly to further consolidate the dimensions calculations as based on the number of actions present (anticipating that this could potentially change in the future).

[getdave]

I agree with adding a button to allow submission.

I think "RESET" is probably an edge case and not a primary action.

Therefore, if we need to remove one to save space and reduce UI clutter (and potential choice paralysis) then I vote to remove Reset.

[aduth]

Noting that this was cherry-picked to be absorbed into the efforts at #20052, though this one could still be landed separately as more targeted to the specific change.

[aduth]

Closing, since #20052 included the changes proposed here.