Open a submenu from a menu item

Plan step 22, actions.md § Missing (Submenus): M3's Expressive vertical
menu specifies submenus and the Left/Right keys that open and close them,
and the library had neither.

`<x-menu-item submenu>` puts its slot in a second popover on the item's
end, flipping to the start where there is no room. `materialSubmenu`
reuses the menu button pattern one level in: the item is its own trigger,
so the anchor move and the button lookup are overridden away; Right,
Enter and Space open it, Left and Escape close it and return the focus,
and a fine pointer resting on the item opens it after a moment. `items()`
now stops at the popover it belongs to, so the arrows never walk between
a menu and an open submenu. The menu publishes its container as custom
properties so a vibrant menu's submenus are vibrant too.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
This commit is contained in:
Andreas Reinhold / reini
2026-09-14 06:31:56 +02:00
co-authored by Claude Opus 5
parent d74fa250ee
commit 25091ebf21
7 changed files with 462 additions and 205 deletions
@@ -261,7 +261,18 @@ M3's plain tooltip, standalone around any trigger: `<x-tooltip text="Copy link"
</x-menu>
```
`<x-menu>`: `trigger` slot (its first button or link becomes the menu button, and the menu hangs on that button — a `position: fixed` trigger such as `<x-button fab>` carries it along, and a menu with no room flips to the other side, end or both), `label`, `position` (`bottom-start` default, `bottom-end`, `top-start`, `top-end`), `vibrant`. `<x-menu-item>`: `label`, `icon`, `icon-class` (classes for the leading icon; a colour there paints it, a selected item's too, but not a disabled one's — `icon-class="text-sport-run"`), `icon-right`, `description`, `shortcut`, `link`, `external`, `selected` (makes it a `menuitemcheckbox`, ticked at its end unless it has an `icon-right`), `current` (for a menu of places: marks the page you are on with `aria-current="page"` in secondary-container, never a checked choice), `badge` (`true` for a dot, or a count, at the end of the row), `disabled`, `keep-open`. Choosing an item closes the menu unless `keep-open`; a second press on the menu button closes it too. An open menu stays open while the Livewire component around it renders, a `keep-open` item's own `wire:click` included. Keyboard: arrows, Home, End, a letter, Escape (focus returns to the trigger), Tab; a `disabled` item keeps its place in that order, as M3 asks, but cannot be activated. A menu longer than the window scrolls.
`<x-menu>`: `trigger` slot (its first button or link becomes the menu button, and the menu hangs on that button — a `position: fixed` trigger such as `<x-button fab>` carries it along, and a menu with no room flips to the other side, end or both), `label`, `position` (`bottom-start` default, `bottom-end`, `top-start`, `top-end`), `vibrant`. `<x-menu-item>`: `label`, `icon`, `icon-class` (classes for the leading icon; a colour there paints it, a selected item's too, but not a disabled one's — `icon-class="text-sport-run"`), `icon-right`, `description`, `shortcut`, `link`, `external`, `selected` (makes it a `menuitemcheckbox`, ticked at its end unless it has an `icon-right`), `current` (for a menu of places: marks the page you are on with `aria-current="page"` in secondary-container, never a checked choice), `badge` (`true` for a dot, or a count, at the end of the row), `disabled`, `keep-open`, `submenu`. Choosing an item closes the menu unless `keep-open`; a second press on the menu button closes it too. An open menu stays open while the Livewire component around it renders, a `keep-open` item's own `wire:click` included. Keyboard: arrows, Home, End, a letter, Escape (focus returns to the trigger), Tab; a `disabled` item keeps its place in that order, as M3 asks, but cannot be activated. A menu longer than the window scrolls.
`submenu` makes an item a menu of its own — the slot holds the nested `<x-menu-item>`s instead of a label, and they open beside it, on its end, flipping to its start where the window has no room:
```blade
<x-menu-item label="Export as" icon="download" submenu>
<x-menu-item label="ZIP" icon="folder_zip" wire:click="exportZip" />
<x-menu-item label="PDF" icon="picture_as_pdf" wire:click="exportPdf" />
</x-menu-item>
```
The item says so with `aria-haspopup="menu"`, `aria-expanded` and a chevron; Right, Enter or Space open it on its first item, Left or Escape close it and come back, and on a fine pointer resting on the item opens it. Choosing anything inside closes the whole menu. Arrows stay inside the list they are in. M3 calls submenus a large-screen pattern — on a phone give the menu `sheet-at-compact`, or keep the list flat.
### `<x-button-group>`