svelte-kit-vice/web/routes/uix/components/heading/+page.svelte

<script lang="ts">
	import {
		Heading,
		type HeadingLevel,
		type HeadingStyle,
		type HeadingSize,
		type HeadingFamily,
		type HeadingWeight,
		type HeadingColor,
		type HeadingAlign
	} from '$uix/eidos/components/heading';
	import { compileMorfo } from '$uix/morfo';
	import { headingMorfo } from '@/uix/morfo/components/heading';

	type Tab = 'live' | 'api' | 'morfo' | 'sema' | 'recipe' | 'a11y';
	type TraceEntry = { event: string; family: string; intent?: string; at: number };
	let tab = $state<Tab>('live');
	let trace = $state<TraceEntry[]>([]);
	let stageRef = $state<HTMLElement | null>(null);

	// ── Live state ────────────────────────────────────────────────────────
	let level = $state<HeadingLevel>(2);
	let headingStyle = $state<HeadingStyle | ''>('');
	let size = $state<HeadingSize | ''>('');
	let family = $state<HeadingFamily | ''>('');
	let weight = $state<HeadingWeight | ''>('');
	let color = $state<HeadingColor | ''>('');
	let align = $state<HeadingAlign | ''>('');
	let italic = $state(false);
	let underline = $state(false);
	let truncate = $state(false);
	let clamp = $state<number>(0);
	let content = $state('Designed for the eidos visual layer.');

	const levelOptions: HeadingLevel[] = [1, 2, 3, 4, 5, 6];
	const styleOptions = ['', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'] as const;
	const sizes: HeadingSize[] = ['xxs', 'xs', 'sm', 'md', 'lg', 'xl', 'xxl', 'xxxl'];
	const families: HeadingFamily[] = ['primary', 'secondary', 'mono', 'display'];
	const weights: HeadingWeight[] = ['regular', 'medium', 'semibold', 'bold'];
	const colors: HeadingColor[] = ['primary', 'secondary', 'muted', 'disabled', 'on-solid'];
	const alignOptions = ['', 'start', 'center', 'end', 'justify'] as const;

	// ── Compiled morfo ────────────────────────────────────────────────────
	const compiled = compileMorfo(headingMorfo);
	const partsList = $derived([...compiled.parts.byKebab.values()]);
	const events = $derived([...compiled.actions.byName.values()]);

	$effect(() => {
		const el = stageRef;
		if (!el) return;
		const obs = new MutationObserver((mutations) => {
			for (const m of mutations) {
				if (m.attributeName !== 'data-event') continue;
				const target = m.target as Element;
				const ev = target.getAttribute('data-event');
				if (!ev) continue;
				trace = [
					{
						event: ev,
						family: target.getAttribute('data-event-family') ?? '—',
						intent: target.getAttribute('data-event-intent') ?? undefined,
						at: Date.now()
					},
					...trace
				].slice(0, 6);
			}
		});
		obs.observe(el, { attributes: true, subtree: true, attributeFilter: ['data-event'] });
		return () => obs.disconnect();
	});

	// ── Code snippets ─────────────────────────────────────────────────────
	const somaSnippet = $derived(
		[
			'<!-- Heading is eidos-native — no soma layer. -->',
			'<!-- Equivalent semantic markup: -->',
			'',
			`<h${level}`,
			'  data-heading',
			`  data-style="${headingStyle || `h${level}`}"`,
			headingStyle && headingStyle !== `h${level}` && '  <!-- semantic and visual decoupled -->',
			'>',
			`  ${content}`,
			`</h${level}>`
		]
			.filter(Boolean)
			.join('\n')
	);

	const eidosSnippet = $derived(
		[
			"<script lang='ts'>",
			"  import { Heading } from '$uix/eidos/components/heading';",
			'</' + 'script>',
			'',
			'<Heading',
			level !== 2 && `  level={${level}}`,
			headingStyle && `  style="${headingStyle}"`,
			size && `  size="${size}"`,
			family && `  family="${family}"`,
			weight && `  weight="${weight}"`,
			color && `  color="${color}"`,
			align && `  align="${align}"`,
			italic && '  italic',
			underline && '  underline',
			truncate && '  truncate',
			clamp > 0 && `  clamp={${clamp}}`,
			'>',
			'  ' + content,
			'</Heading>'
		]
			.filter(Boolean)
			.join('\n')
	);
</script>

<div data-uix-canvas-inner>
	<header>
		<div data-uix-eyebrow>Typography · Heading</div>
		<h1 data-uix-page-title>Heading</h1>
		<p data-uix-page-lede>
			Semantic heading typography primitive. <code>level</code> chooses the HTML tag
			(<code>h1</code>..<code>h6</code>) and <code>style</code> chooses the visual treatment — by
			default they mirror each other but can be decoupled
			(<code>{`<Heading level={3} style="h1">`}</code>) for visual-h1-with-semantic-h3 cases.
			Single part. Eidos-native: no soma backing, no semantic events.
		</p>
		<div data-uix-page-meta>
			<span data-uix-meta-pill>
				<span data-uix-meta-key>parts</span>{compiled.parts.order.length}
			</span>
			<span data-uix-meta-pill>
				<span data-uix-meta-key>events</span>0
			</span>
			<span data-uix-meta-pill>
				<span data-uix-meta-key>levels</span>6
			</span>
			<span data-uix-meta-pill>
				<span data-uix-meta-key>styles</span>6
			</span>
			<span data-uix-meta-pill>
				<span data-uix-meta-key>scope</span>eidos
			</span>
		</div>
	</header>

	<div data-uix-stage>
		<div data-uix-stage-area bind:this={stageRef}>
			<div
				style="max-inline-size: 38rem; padding: var(--space-3); border: 1px dashed var(--color-neutral-border); border-radius: var(--radius-md);"
			>
				<Heading
					{level}
					style={headingStyle || undefined}
					size={size || undefined}
					family={family || undefined}
					weight={weight || undefined}
					color={color || undefined}
					align={align || undefined}
					{italic}
					{underline}
					{truncate}
					clamp={clamp > 0 ? clamp : undefined}
				>
					{content}
				</Heading>
			</div>
		</div>
		<div data-uix-stage-trace>
			<span data-uix-stage-trace-key>trace</span>
			<span>{trace.length === 0 ? 'no semantic events' : `${trace.length} event(s)`}</span>
			<span style="color: var(--uix-text-faint)">·</span>
			<span data-uix-stage-trace-key>level</span>
			<span>h{level}</span>
			<span style="margin-inline-start: auto;">
				<span data-uix-stage-trace-key>style</span> {headingStyle || `h${level}`} ·
				<span data-uix-stage-trace-key>size</span> {size || 'inherit'}
			</span>
		</div>
	</div>

	<div data-uix-tabs role="tablist">
		<button data-uix-tab data-active={tab === 'live'} onclick={() => (tab = 'live')}>Live</button>
		<button data-uix-tab data-active={tab === 'api'} onclick={() => (tab = 'api')}>
			API <span data-uix-tab-count>11</span>
		</button>
		<button data-uix-tab data-active={tab === 'morfo'} onclick={() => (tab = 'morfo')}>
			<span data-uix-layer-badge="morfo">morfo</span>
			<span data-uix-tab-count>{partsList.length}p · 0e</span>
		</button>
		<button data-uix-tab data-active={tab === 'sema'} onclick={() => (tab = 'sema')}>
			<span data-uix-layer-badge="sema">sema</span>
			<span data-uix-tab-count>{events.length}</span>
		</button>
		<button data-uix-tab data-active={tab === 'recipe'} onclick={() => (tab = 'recipe')}
			>Recipe</button
		>
		<button data-uix-tab data-active={tab === 'a11y'} onclick={() => (tab = 'a11y')}>A11y</button>
	</div>

	{#if tab === 'live'}
		<section data-uix-section>
			<h2 data-uix-section-title>Controls</h2>
			<p data-uix-section-desc>
				Heading is eidos-native — no <span data-uix-layer-badge="soma">soma</span> split. The
				<code>level</code> prop drives semantics; <code>style</code> drives visual weight (defaults
				to mirror level). Per-axis overrides write inline
				<code>--_heading-*</code> CSS variables.
			</p>

			<div data-uix-subsection-head>
				<span data-uix-layer-badge="eidos">eidos</span> props · semantic + visual
			</div>
			<div data-uix-controls>
				<label data-uix-control>
					<span data-uix-control-label
						>level <span data-uix-control-hint>HTML tag</span></span
					>
					<span data-uix-chips role="radiogroup">
						{#each levelOptions as opt}
							<button
								data-uix-chip
								data-active={level === opt}
								onclick={() => (level = opt)}>h{opt}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label
						>style <span data-uix-control-hint>visual scale, default mirrors level</span></span
					>
					<span data-uix-chips role="radiogroup">
						{#each styleOptions as opt}
							<button
								data-uix-chip
								data-active={headingStyle === opt}
								onclick={() => (headingStyle = opt)}>{opt || 'auto'}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>size override</span>
					<span data-uix-chips role="radiogroup">
						<button
							data-uix-chip
							data-active={size === ''}
							onclick={() => (size = '')}>inherit</button
						>
						{#each sizes as opt}
							<button
								data-uix-chip
								data-active={size === opt}
								onclick={() => (size = opt)}>{opt}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>family override</span>
					<span data-uix-chips role="radiogroup">
						<button
							data-uix-chip
							data-active={family === ''}
							onclick={() => (family = '')}>inherit</button
						>
						{#each families as opt}
							<button
								data-uix-chip
								data-active={family === opt}
								onclick={() => (family = opt)}>{opt}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>weight override</span>
					<span data-uix-chips role="radiogroup">
						<button
							data-uix-chip
							data-active={weight === ''}
							onclick={() => (weight = '')}>inherit</button
						>
						{#each weights as opt}
							<button
								data-uix-chip
								data-active={weight === opt}
								onclick={() => (weight = opt)}>{opt}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label
						>color override <span data-uix-control-hint>content-role slot</span></span
					>
					<span data-uix-chips role="radiogroup">
						<button
							data-uix-chip
							data-active={color === ''}
							onclick={() => (color = '')}>inherit</button
						>
						{#each colors as opt}
							<button
								data-uix-chip
								data-active={color === opt}
								onclick={() => (color = opt)}>{opt}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>align</span>
					<span data-uix-chips role="radiogroup">
						{#each alignOptions as opt}
							<button
								data-uix-chip
								data-active={align === opt}
								onclick={() => (align = opt)}>{opt || 'inherit'}</button
							>
						{/each}
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>italic</span>
					<span data-uix-switch>
						<input type="checkbox" bind:checked={italic} />
						<span data-uix-switch-label>{italic ? 'on' : 'off'}</span>
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label>underline</span>
					<span data-uix-switch>
						<input type="checkbox" bind:checked={underline} />
						<span data-uix-switch-label>{underline ? 'on' : 'off'}</span>
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label
						>truncate <span data-uix-control-hint>single-line ellipsis</span></span
					>
					<span data-uix-switch>
						<input type="checkbox" bind:checked={truncate} />
						<span data-uix-switch-label>{truncate ? 'on' : 'off'}</span>
					</span>
				</label>
				<label data-uix-control>
					<span data-uix-control-label
						>clamp <span data-uix-control-hint>multi-line cap (0 = off)</span></span
					>
					<input
						type="number"
						min="0"
						max="10"
						step="1"
						bind:value={clamp}
						style="inline-size: 6rem;"
					/>
				</label>
				<label data-uix-control style="grid-column: span 2;">
					<span data-uix-control-label>content</span>
					<textarea bind:value={content} rows="2" style="inline-size: 100%; font: inherit;"
					></textarea>
				</label>
			</div>

			<div data-uix-code>
				<div data-uix-code-head>
					<span data-uix-layer-badge="soma">soma</span>
					<span>n/a · heading is eidos-native — equivalent markup shown</span>
					<span data-uix-code-lang>svelte</span>
				</div>
				<pre><code>{somaSnippet}</code></pre>
			</div>

			<div data-uix-code style="margin-top: var(--uix-space-3);">
				<div data-uix-code-head>
					<span data-uix-layer-badge="eidos">eidos</span>
					<span>visual · level + style + per-axis overrides</span>
					<span data-uix-code-lang>svelte</span>
				</div>
				<pre><code>{eidosSnippet}</code></pre>
			</div>
		</section>
	{/if}

	{#if tab === 'api'}
		<section data-uix-section>
			<h2 data-uix-section-title>API reference</h2>
			<p data-uix-section-desc>
				<code>level</code> renders <code>{`<h{level}>`}</code>; <code>style</code> selects the
				<code>{`--style-h{n}-*`}</code> token set (defaults to mirror level). Per-axis props
				override individual fields without breaking the named-style cascade.
			</p>

			<div data-uix-subsection-head>Semantic + visual</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Prop</th><th>Type</th><th>Default</th><th>Notes</th></tr></thead>
					<tbody>
						<tr
							><td class="name">level</td><td class="type">1 | 2 | 3 | 4 | 5 | 6</td><td
								class="default">2</td
							><td>Renders <code>{`<h{level}>`}</code>. Drives semantic hierarchy.</td></tr
						>
						<tr
							><td class="name">style</td><td class="type">'h1' | 'h2' | 'h3' | 'h4' | 'h5' | 'h6'</td
							><td class="default">mirrors level</td><td
								>Visual treatment. Decouples from level when set explicitly.</td
							></tr
						>
					</tbody>
				</table>
			</div>

			<div data-uix-subsection-head>Per-axis overrides</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Prop</th><th>Type</th><th>Notes</th></tr></thead>
					<tbody>
						<tr
							><td class="name">size</td><td class="type"
								>'xxs' | 'xs' | 'sm' | 'md' | 'lg' | 'xl' | 'xxl' | 'xxxl'</td
							><td>Resolves to <code>{`var(--font-size-{key})`}</code>.</td></tr
						>
						<tr
							><td class="name">family</td><td class="type"
								>'primary' | 'secondary' | 'mono' | 'display'</td
							><td>Resolves to <code>{`var(--font-family-{key})`}</code>.</td></tr
						>
						<tr
							><td class="name">weight</td><td class="type"
								>'regular' | 'medium' | 'semibold' | 'bold'</td
							><td>Resolves to <code>{`var(--font-weight-{key})`}</code>.</td></tr
						>
						<tr
							><td class="name">color</td><td class="type"
								>'primary' | 'secondary' | 'muted' | 'disabled' | 'on-solid'</td
							><td>Resolves to <code>{`var(--color-content-{key})`}</code>.</td></tr
						>
						<tr
							><td class="name">align</td><td class="type"
								>'start' | 'center' | 'end' | 'justify'</td
							><td>Maps to <code>text-align</code>.</td></tr
						>
					</tbody>
				</table>
			</div>

			<div data-uix-subsection-head>Shorthand booleans + truncation</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Prop</th><th>Type</th><th>Notes</th></tr></thead>
					<tbody>
						<tr><td class="name">italic</td><td class="type">boolean</td><td><code>font-style: italic</code>.</td></tr>
						<tr><td class="name">underline</td><td class="type">boolean</td><td><code>text-decoration: underline</code>.</td></tr>
						<tr><td class="name">truncate</td><td class="type">boolean</td><td>Single-line ellipsis. Requires container width.</td></tr>
						<tr><td class="name">clamp</td><td class="type">number</td><td>Multi-line cap via <code>-webkit-line-clamp</code>.</td></tr>
					</tbody>
				</table>
			</div>

			<div data-uix-subsection-head>Element + escape hatch</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Prop</th><th>Type</th><th>Notes</th></tr></thead>
					<tbody>
						<tr><td class="name">as</td><td class="type">string</td><td>Override the rendered tag. Defaults to <code>{`h{level}`}</code>.</td></tr>
						<tr><td class="name">tagStyle</td><td class="type">string</td><td>Extra inline CSS. Appended after the recipe's vars.</td></tr>
					</tbody>
				</table>
			</div>

			<div data-uix-subsection-head>Reference comparison</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Library</th><th>Closest equivalent</th><th>Difference</th></tr></thead>
					<tbody>
						<tr><td class="name">radix-themes</td><td><code>&lt;Heading&gt;</code></td><td>Radix conflates semantic + visual into <code>as</code> + numeric size; UIX keeps them as separate props.</td></tr>
						<tr><td class="name">chakra-ui</td><td><code>&lt;Heading&gt;</code></td><td>Chakra ties visual via <code>fontSize</code> only; UIX adds named foundation styles.</td></tr>
						<tr><td class="name">mantine</td><td><code>&lt;Title order={`{1..6}`}&gt;</code></td><td>Mantine's <code>order</code> drives both; UIX splits via level/style.</td></tr>
						<tr><td class="name">mui Typography</td><td><code>&lt;Typography variant="h1"&gt;</code></td><td>MUI <code>variant</code> ≈ UIX <code>style</code>; consumer composes <code>component="h3"</code> for the semantic split.</td></tr>
					</tbody>
				</table>
			</div>
		</section>
	{/if}

	{#if tab === 'morfo'}
		<section data-uix-section>
			<h2 data-uix-section-title>Morfo contract</h2>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Field</th><th>Value</th></tr></thead>
					<tbody>
						<tr><td class="name">name</td><td>{headingMorfo.name}</td></tr>
						<tr><td class="name">kebab</td><td><code>{headingMorfo.kebab}</code></td></tr>
						<tr><td class="name">scope</td><td>{headingMorfo.scope.join(', ')}</td></tr>
						<tr><td class="name">parts</td><td>{partsList.length}</td></tr>
						<tr><td class="name">events</td><td>0</td></tr>
					</tbody>
				</table>
			</div>

			<div data-uix-subsection-head>Parts</div>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead
						><tr
							><th>kebab</th><th>marker</th><th>element</th><th>archetype</th><th>optional</th
							></tr
						></thead
					>
					<tbody>
						{#each partsList as part}
							<tr>
								<td class="name">{part.kebab}</td>
								<td><code data-uix-part-marker>[{part.marker}]</code></td>
								<td class="type">&lt;{part.defaultElement}&gt;</td>
								<td class="type">{part.archetype}</td>
								<td class="default">{part.optional ? 'yes' : 'no'}</td>
							</tr>
						{/each}
					</tbody>
				</table>
			</div>

			<p data-uix-section-desc style="margin-top: var(--uix-space-4);">
				The Provider stamps <code>data-heading</code> on the rendered
				<code>{`<h{level}>`}</code>
				tag (or the override from <code>as</code>) plus <code>data-level</code>,
				<code>data-style</code> and the boolean modifier attrs (<code>data-italic</code>,
				<code>data-underline</code>, <code>data-truncate</code>, <code>data-clamp</code>). The
				recipe selects the named-style fallback chain via <code>data-style</code>; per-axis
				overrides come through inline <code>--_heading-*</code> CSS variables.
			</p>
		</section>
	{/if}

	{#if tab === 'sema'}
		<section data-uix-section>
			<h2 data-uix-section-title>
				<span data-uix-layer-badge="sema">sema</span> · events
			</h2>
			<p data-uix-section-desc>
				Heading declares no semantic events. As a passive typography primitive, the headline does
				not commit, emerge, or react — it just renders its visual treatment. Components that
				animate headings on appearance (dialog title, collapsible reveal, toast title) compose
				Heading inside the interactive primitive that owns the relevant sema verb.
			</p>
		</section>
	{/if}

	{#if tab === 'recipe'}
		<section data-uix-section>
			<h2 data-uix-section-title>Eidos recipe</h2>
			<p data-uix-section-desc>
				Recipe lives in <code>src/uix/eidos/components/heading/heading.css</code>. The selector
				<code>[data-heading]</code> applies the default h2 cascade; matching <code>data-style</code>
				swaps to the corresponding <code>{`--style-h{n}-*`}</code> tokens. Per-axis overrides come
				from <code>--_heading-*</code> custom properties written inline by the wrapper.
			</p>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Selector</th><th>Owner</th><th>Purpose</th></tr></thead>
					<tbody>
						<tr><td class="name"><code>[data-heading]</code></td><td><span data-uix-tag data-kind="morfo">morfo</span></td><td>Provider marker. Default h2-style applied.</td></tr>
						<tr><td class="name"><code>{`[data-heading][data-style='h1'..'h6']`}</code></td><td><span data-uix-tag data-kind="eidos">eidos</span></td><td>Swap to the named style's token set.</td></tr>
						<tr><td class="name"><code>{`[data-heading][data-italic|data-underline|data-truncate|data-clamp]`}</code></td><td><span data-uix-tag data-kind="eidos">eidos</span></td><td>Visual modifier flags from boolean props.</td></tr>
					</tbody>
				</table>
			</div>
		</section>
	{/if}

	{#if tab === 'a11y'}
		<section data-uix-section>
			<h2 data-uix-section-title>Accessibility</h2>
			<div data-uix-table-wrap>
				<table data-uix-table>
					<thead><tr><th>Concern</th><th>Contract</th></tr></thead>
					<tbody>
						<tr><td class="name">Role</td><td>Native HTML heading semantics from <code>{`<h{level}>`}</code>. AT announce the heading and its level automatically.</td></tr>
						<tr><td class="name">Heading hierarchy</td><td>Consumer responsibility — pass <code>level</code> per outline depth. Don't skip levels (h2 then h4).</td></tr>
						<tr><td class="name">Visual ≠ semantic</td><td>Decoupling via <code>{`level={3} style="h1"`}</code> is safe for AT — they read the level, not the visual style.</td></tr>
						<tr><td class="name">Truncation + AT</td><td>CSS-only — full text remains in DOM. AT read the full heading.</td></tr>
						<tr><td class="name">Color contrast</td><td>Content-role colors meet WCAG AA. Free colors via <code>tagStyle</code> bypass that guarantee.</td></tr>
					</tbody>
				</table>
			</div>
		</section>
	{/if}
</div>