* [RFC] Proof-of-concept commit for submenu support
This is a Request For Comments to seek directional guidance towards
implementing the submenu slot of menu-item.
Includes:
- SubmenuController to manage event listeners on menu-item.
- Example usage in menu-item documentation.
- Trivial tests to check rendering.
Outstanding questions include:
- Accessibility concerns. E.g. where to handle 'ArrowRight',
'ArrowLeft'?
- Should selection of menu-item denoting submenu be possible or
customizable?
- How to parameterize contained popup?
- Implementation concerns:
- Use of ref / id
- delegation of some rendering to the controller
- What to test
Related to [#620](https://github.com/shoelace-style/shoelace/issues/620).
* Update submenu-controller.ts
Removed extraneous `console.log()`.
* PoC working of ArrowRight to focus on submenu.
* Revert "PoC working of ArrowRight to focus on submenu."
(Didn't mean to publish this.)
This reverts commit be04e9a221.
* [WIP] Submenu WIP continues.
- Submenus now close on change-of-focus, not a timeout.
- Keyboard navigation support added.
- Skidding fix for better alignment.
- Submenu documentation moved to Menu page.
- Tests for accessibility, right and left arrow keys.
* Cleanup: Removed dead code and dead code comments.
* style: Eslint warnings and errors fixed. npm run verify now passes.
* fix: 2 changes to menu / submenu on-click behavior:
1. Close submenu on click explicitly, so this occurs even if the menu is
not inside of an sl-dropdown.
2. In menu, ignore clicks that do not explicitly target a menu-item.
Clicks that were on (e.g. a menu-border) were emitting select events.
* fix: Prevent menu's extraneous Enter / space key propagation.
Menu's handleKeyDown calls item.click (to emit the selection).
Propagating the keyboard event on Enter / space would the cause re-entry
into a submenu, so prevent the needless propagation.
* Submenu tweaks ...
- 100 ms delay when opening submenus on mouseover
- Shadows added
- Distance added to popup to have submenus overlap menu slightly.
* polish up submenu stuff
* stay highlighted when submenu is open
* update changelog
* resolve feedback
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Co-authored-by: Bryce Moore <bryce.moore@gmail.com>
