livewire-material/resources/views/components/bottom-sheet.blade.php

{{-- An M3 bottom sheet: secondary content or actions anchored to the bottom of the screen.

     Modal by default: over a scrim, the page inert and still, dismissed by the scrim, Escape, or a
     downward drag on its handle (or anywhere on the sheet when its content is scrolled to the top).
     `standard` makes it part of the page instead — no scrim, nothing inert, and it stays until closed.
     The open state works as for `<x-drawer>`: `wire:model` (a flag or an id, written back `false` or
     `null` on close) or `open` in the surrounding Alpine scope; `close()` is in scope inside it.

     SheetBottomTokens (androidx Compose Material 3, Apache-2.0): surface-container-low, extra-large
     top corners, elevation 1, a 32×4px drag handle in on-surface-variant; 640px wide at most, centred
     on a wide screen; it rises on emphasized decelerate. `title` and `actions` as on a dialog.

     `height` is where it opens, and M3 caps a modal sheet's initial position at half the screen —
     "if content exceeds that, it can be pulled to full screen and scrolled internally" — so the
     default is `50dvh`, under a ceiling of the screen less M3's 72dp top margin. Content scrolls
     inside.

     `heights` gives the sheet M3's **preset heights**: a list of stops — `heights="25dvh,50dvh,90dvh"`,
     `:heights="[25, 50, 90]"` (a bare number is read as `dvh`) or a JSON list — and the sheet then
     takes the height of its current stop rather than sizing itself to its content. `snap` is the
     shorthand for the library's three, `25dvh`, `50dvh` and `90dvh`. It opens at the stop that equals
     `height`, or at the first one; fewer than two stops is no stops at all, since a single height is
     what `height` already says.

     With stops the drag handle is M3's height control, which is the accessibility rule behind them:
     "the drag handle can be dragged **or selected** to cycle through preset heights", "any drag-only
     action needs a single-pointer alternative", "Tab focuses the drag handle; Space/Enter toggles
     between available heights", and "selecting the drag handle toggles preset heights **or closes the
     sheet**". So activating the handle — a click, Enter or Space, since it is a button — moves to the
     next stop and announces it in a live region, and from the last stop it closes the sheet, which is
     also what a handle with no stops does. A drag runs the sheet's height with the pointer and
     settles on the nearest stop on release, or closes it below the smallest one or on a downward
     flick (docs/reference/m3/components-actions-communication-containment.md § Bottom sheets →
     Behaviour, Accessibility).

     The handle's wrapper is the drag target and M3's 48dp hit area: the button's own visual bar is
     32×4px, and `md-touch-target` (foundation/interaction.css) extends it, while the wrapper's own
     22px top/bottom padding (`SheetDefaults.kt`'s `DragHandleVerticalPadding`) gives the row its
     M3-specified height regardless — 4 + 22 + 22 = 48px (C-01). The button renders the shared
     `md-focus-ring` and `md-touch-target` classes rather than a hand-rolled ring: unlike the
     datepicker's day, its own visible bar is not a smaller indicator drawn inside a bigger box the
     classes cannot reach — the box the classes draw is the button's whole hit area.

     The root renders `data-md-bottom-sheet` (data-md-open, data-md-standard); the parts are
     `data-md-bottom-sheet-scrim`, `-panel` (data-md-preset while stops exist), `-handle` (the drag
     target), `-grip` (the 32×4px bar), `-announce`, `-body`, `-title`, `-actions` — drawn by
     resources/css/components/bottom-sheet.css. `<x-menu sheet-at-compact>` renders this component
     for its compact presentation. --}}

@props([
    'title' => null,
    'standard' => false,
    'height' => '50dvh',
    'heights' => null,
    'snap' => false,
])

@php
    $model = $attributes->wire('model')->value() ?: null;
    $id = $attributes->get('id') ?? 'material-bottom-sheet-'.substr(md5($model.'|'.$title), 0, 10);

    // A list, a JSON list or a comma-separated one; a bare number is a percentage of the screen,
    // which is how M3 talks about a sheet's position ("capped at 50% of screen height").
    $stops = match (true) {
        is_array($heights) => $heights,
        is_string($heights) && str_starts_with(trim($heights), '[') => json_decode($heights, true) ?: [],
        filled($heights) => explode(',', (string) $heights),
        (bool) $snap => ['25dvh', '50dvh', '90dvh'],
        default => [],
    };

    $stops = array_values(array_filter(array_map(
        fn ($stop): string => is_numeric($stop) ? ((float) $stop).'dvh' : trim((string) $stop),
        $stops,
    ), 'filled'));

    // M3 asks for a non-drag way to change height "if multiple preset heights exist"; one stop is
    // not multiple, and `height` already says where a single-height sheet opens.
    $stops = count($stops) > 1 ? $stops : [];
    $start = (int) (array_search($height, $stops, true) ?: 0);

    $presets = \Illuminate\Support\Js::from([
        'stops' => $stops,
        'start' => $start,
        'labels' => [
            'change' => __('Change the sheet height'),
            'close' => __('Close'),
            'announce' => array_map(
                fn (int $index): string => __('Height :position of :count', ['position' => $index + 1, 'count' => count($stops)]),
                array_keys($stops),
            ),
        ],
    ]);
@endphp

<div
    x-data="{
        ...materialBottomSheet({{ $standard ? 'true' : 'false' }}, {{ $presets }}),
        @if ($model !== null) open: @entangle($attributes->wire('model')).live, @endif
    }"
    x-on:keydown.window.escape="if (open && ! standard) close()"
    x-bind:data-md-open="open ? '' : null"
    data-md-bottom-sheet
    @if ($standard) data-md-standard @endif
>
    @unless ($standard)
        <div data-md-bottom-sheet-scrim x-cloak x-show="open" x-on:click="close()" aria-hidden="true"></div>
    @endunless

    @if ($stops !== [])
        {{-- A stop is a CSS length, and only the browser can say what `25dvh` is in pixels; this
             measures one when a drag has to find the nearest. --}}
        <div x-ref="probe" data-md-bottom-sheet-probe aria-hidden="true"></div>
    @endif

    <section
        x-cloak
        x-show="open"
        x-ref="sheet"
        @unless ($standard) x-trap.inert.noscroll="open" @endunless
        x-bind:style="sheetStyle"
        x-on:pointerdown="dragStart($event)"
        id="{{ $id }}"
        role="dialog"
        @unless ($standard) aria-modal="true" @endunless
        @if (filled($title)) aria-labelledby="{{ $id }}-title" @endif
        data-md-bottom-sheet-panel
        @if ($stops !== []) data-md-preset @endif
        @if ($stops === [])
            style="--sheet-max-height: min({{ $height }}, calc(100dvh - 72px))"
        @else
            style="--sheet-stop: {{ $stops[$start] }}; --sheet-max-height: min(var(--sheet-stop), calc(100dvh - 72px))"
        @endif
        {{ $attributes->whereDoesntStartWith('wire:model')->except(['id']) }}
    >
        <div data-md-bottom-sheet-handle>
            <button
                type="button"
                class="md-focus-ring md-touch-target"
                data-md-bottom-sheet-grip
                aria-label="{{ $stops === [] ? __('Close') : __('Change the sheet height') }}"
                @if ($stops !== []) x-bind:aria-label="handleLabel" @endif
                x-on:click="activate()"
            ></button>
        </div>

        @if ($stops !== [])
            <span data-md-bottom-sheet-announce class="md-visually-hidden" aria-live="polite" x-text="announcement"></span>
        @endif

        <div x-ref="body" data-md-bottom-sheet-body>
            @if (filled($title))
                <h2 id="{{ $id }}-title" data-md-bottom-sheet-title>{{ $title }}</h2>
            @endif

            {{ $slot }}
        </div>

        @isset($actions)
            <div data-md-bottom-sheet-actions>{{ $actions }}</div>
        @endisset
    </section>
</div>