Cannot edit existing link in URLInput

[afercia]

When inserting a link or a "@" username mention, clicking on a link or moving the caret on a link makes an inline "popup" appear. The popup contains controls to edit the link, remove the link, additional settings (e.g. open in a new window):

Although the popup is "inline" and it is possible to press Tab and move focus to it, there are a few missing features compared to the similar link inline toolbar in the Classic Editor:

• Alt+F8 should move focus to the popup
• Escape should move focus back from the popup to the link, to the previous caret position or selection
• pressing Tab and arrow keys should loop through the popup controls
• tabbing should be constrained within the popup

Also, to match the current functionality in the Classic Editor, Cmd/Ctrl + K should switch the popup to edit mode. Currently, it is only possible to click the two edit buttons, with different results:

• clicking the Edit button within the modal, will switch to edit mode populating the input field with the current link URL
• clicking the Edit button in the top fixed toolbar, will switch to edit mode but the input field is empty

Also, when editing an username "mention", what should happen? Should the popup appear in edit mode and give users the ability to manually edit the link to the user page or present again the list of username suggestions?

Current behavior:

[JeroenSormani]

It may be an new issue / working before, but I believe also a accessibility case would be that the word that was selected to be linked is no longer highlighted;

The 'Hello' word is selected here to be linked.
(The positioning error is reported at #6183)

[afercia]

Some time has passed since Nov 6 2017, when this issue was created and some things have changed. for example, mentions don't insert a link any longer.

However, it would be greatly beneficial to review again all the "insert link" popups, check the interaction consistency, and the points mentioned above.

[designsimply]

Agree about needing to re-check the interaction consistency. Added a Needs Testing label for that purpose.

Note: a separate issue has been filed at #6156 for the issue @JeroenSormani mentioned where the link text does not appear to be selected when you are adding a link.

[afercia]

Many components use now a standardised URLInput component, for example in the paragraph block. Here's how it looks like:

Pressing the ellipsis button gives access to the "open in a new window" option. The biggest issue with the current implementation (it uses a "popover") is that it's impossible to edit an existing link using only the keyboard. See #8266

Some of the most evident inconsistencies with other components:

The Button component uses a custom implementation of the URL input field and it misses the option "open in a new window". Also, the design is different:

The Verse block is the only block with an editable area that doesn't have a link button. This is intentional, see bd676b5#r126746200 and while I can understand the reasoning it seems to me a limitation:

Well, to be honest, I'm not sure about the whole purpose of the Verse block but this is another issue.

Related issues: #8265 and #1838

[tofumatt]

This will be fixed by #10983. 🎉