Components: introduce Combobox expandOnFocus property

[retrofox]

What?

This property introduces the expandOnFocus property to the Combobox control component.

Why?

Sometimes, auto-expanding the combo box dropdown is not a desired behavior and could even be considered intrusive.
For instance, AriaKit combobox never auto-expands the dropdown in the focus event.

Screen.Recording.2024-05-16.at.09.25.26.mov

The dropdown opens only when the user types in the input field or clicks on it.

Note: it doesn't change the current behavior to ensure backward compatibilities, which we would consider it.

How?

• It adds the onClick property to the <TokenInput /> component, since it's mandatory to differetiate the onFocus and the onClick event in the <ComboboxControl /> component context
• When focusing the element, it sets isExpanded as true only when the expandOnFocus property is true as well.

Testing Instructions

1. Run storybook
2. Compare the ComboboxControl stories
3. Confirm that Not Expand On Focus does not auto-expand the dropdown when the user focuses on the input element. It's required to type or click on it to open the dropdown:

Screen.Recording.2024-05-16.at.09.21.47.mov

Testing Instructions for Keyboard

Screenshots or screencast

[github-actions]

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Co-authored-by: retrofox <retrofox@git.wordpress.org>
Co-authored-by: mirka <0mirka00@git.wordpress.org>

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[mirka]

Interesting! The APG doesn't suggest a standard expansion logic, and the possible conditions it suggests include some quite particular custom logic. So my understanding is that, ideally, a consumer should be able to control the expansion behavior with much more precision, rather than just blunt conditions like "is focused" or "was clicked". This should be easy to support once we rewrite a v2 with Ariakit.

That said, the enhancement in this PR is small enough, so I don't see why not 👍