Square a button group and the choice drawn as one

Plan step 22, actions.md § Missing (Square-by-default button groups): M3
lists "Default shape | Round, square" as a button-group configuration and
neither `<x-button-group>` nor `<x-group>` had a `shape` prop, so a group
of square buttons still drew round outer corners.

`shape="square"` passes the square corner scale to every child through
`data-shape` and two new variables in groups.css: `--group-outer` is what
the two ends of a group round to (half the height when round, the corner
its inner edges take when square — M3's square table, 4/8/8/16/20dp), and
`--group-square`/`--group-square-pressed` give a standard group's buttons
the scale `<x-button shape="square">` draws. The selected rules keep
`--group-full`, so a selected button in a square group rounds: M3 has a
toggle inside a group swap shape on selection either way.

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 06:40:14 +02:00
co-authored by Claude Opus 5
parent 88c46001fb
commit 5d0e9bc12f
6 changed files with 96 additions and 11 deletions
@@ -280,7 +280,7 @@ Clusters: `<x-menu-separator />` draws M3's line, `<x-menu-group gap>` M3 Expres
### `<x-button-group>`
A row of `<x-button>`s: `<x-button-group label="View" size="md">…</x-button-group>`. `connected` sets them 2px apart with small inner corners (a selected toggle rounds fully). Pass the `size` of the buttons inside.
A row of `<x-button>`s: `<x-button-group label="View" size="md">…</x-button-group>`. `connected` sets them 2px apart with small inner corners (a selected toggle rounds fully). Pass the `size` of the buttons inside. `shape="square"` is M3's square group and covers every button in it, so do not write `shape` on each one: a connected group's ends square to the corner its inner edges take, a standard group's buttons take the square corner scale, and a selected button still rounds — M3 has the toggle morph the other way.
### `<x-group>`
@@ -294,7 +294,7 @@ A choice between a few options as a connected button group of native radios (che
]" hint="Recipients lose access after that" />
```
Props: `label`, `hint`, `hint-class` (classes for the hint, as on the fields; a colour there paints it), `name` (required with `x-model`), `options`, `option-value` (`id`), `option-label` (`name`), `option-icon` (`icon`), `size`, `variant` (`tonal`, `filled`, `outlined`), `multiple`, `inline` (intrinsic width instead of sharing the row). A validation error for the bound property replaces the hint.
Props: `label`, `hint`, `hint-class` (classes for the hint, as on the fields; a colour there paints it), `name` (required with `x-model`), `options`, `option-value` (`id`), `option-label` (`name`), `option-icon` (`icon`), `size`, `variant` (`tonal`, `filled`, `outlined`), `shape` (`round`, `square`), `multiple`, `inline` (intrinsic width instead of sharing the row). A validation error for the bound property replaces the hint.
### `<x-split-button>`