BackTop

Navigation component. This page is the API reference, generated from the source code. Usage guidance and live examples are on the Chinese page.

HeadlessStylesVueReactWeb Components

Anatomy

Parts in bold are required.

data-scope="back-top": root · trigger

API reference

Descriptions of individual props, events and slots are written in Chinese and appear on the Chinese page.

Artifacts

Layer	Value
Custom element	<xh-back-top>
Vue components	XhBackTopRoot XhBackTopTrigger
Composable	useBackTop
State machine	backTopMachine
Skin	@xihan-ui/styles/back-top.css

Props

Prop	Type	Required
visibilityHeight	number
behavior	BackTopBehavior
translations	Partial<BackTopTranslations>
variant	ActionVariant
tone	Tone
size	Size
onVisibilityChange	(details: BackTopVisibilityChangeDetails) => void

Events

Custom elements put the payload in detail; Vue emits an event of the same name.

Event	Payload
visibility-change	BackTopVisibilityChangeDetails

Slots

Only slots with a payload are listed.

Vue component	Slot	Payload
XhBackTopRoot	default	BackTopRootSlotProps

React adapter props

Only the props each component declares itself: DOM attributes inherited from ComponentPropsWithRef are left out, and root props already listed in the Props table are not repeated. The Vue counterpart is the slot table above.

React component	Prop	Type	Required
XhBackTopRoot	target	() => HTMLElement | null
XhBackTopRoot	children	SlotChildren<BackTopRootSlotProps>

State

Public state is written to data-state.

Part	Values
root	'visible' | 'hidden'
trigger	'visible' | 'hidden'

The following names are internal to the state machine.

States: hidden · visible

Events: SCROLL.RESOLVE · TRIGGER.CLICK · PRESS.START · PRESS.END · TRIGGER.RENDERED

Guards: shouldShow · shouldHide

connect API

getXxxProps() returns the host attributes of the matching part.

Member	Type
visible	boolean
scrollToTop	() => void
getRootProps	() => T['element']
getTriggerProps	() => T['button']

Accessibility

Keyboard

Specification: W3C APG. Each row is a stable behavior id that the conformance tests cover; the conditions and effects are described on the Chinese page.

Keys	Behavior
Enter / Space	back-top.kbd.activate
Enter / Space	back-top.kbd.press
Tab / Shift+Tab	back-top.kbd.tab

ARIA

These attributes are produced by connect.

Part	Attribute	Value
trigger	aria-label	translations.trigger

Style reference

Skin

@xihan-ui/styles/back-top.css is written against [data-scope="back-top"][data-part="root"] part selectors; the published build uses the mount class .xh-scope-back-top in place of data-scope (same specificity) and sits in the xihan.components layer. Put overrides in xihan.overrides; the part selectors work as usual.

Data attributes

Produced by connect; valueless attributes are omitted while their condition does not hold.

Part	Attribute	Value
root	data-size	props.size
root	data-state	'visible' | 'hidden'
root	data-tone	props.tone
root	data-variant	props.variant
trigger	data-pressed	'' (present only while the condition holds)
trigger	data-state	'visible' | 'hidden'
trigger	data-xh-action-control	''
trigger	data-xh-action-display	'always'
trigger	data-xh-action-profile	'floating'
trigger	data-xh-action-size	props.size
trigger	data-xh-action-variant	props.variant
trigger	data-xh-ink-surface	'' (present only while the condition holds)
trigger	data-xh-liquid	''
trigger	data-xh-material	'frosted' | undefined

CSS variables

The public override slots, generated from what the standalone skin actually consumes.

Variable	Part	CSS property	State	Default from
--xh-back-top-bg	root trigger	--xh-ink-surface background-color	default disabled focus-visible variant=outline xh-ink-surface	--xh-_action-variant-bg-disabled --xh-_action-variant-bg-focus-visible --xh-_action-variant-bg-rest --xh-_material-bg --xh-_material-bg-focus
--xh-back-top-bg-active	root trigger	background-color	disabled is(:active, [data-pressed]) loading not([data-disabled]) not([data-loading]) pressed variant=outline	--xh-_action-variant-bg-pressed --xh-_material-bg-pressed
--xh-back-top-bg-hover	root trigger	background-color	disabled hover loading not([data-disabled]) not([data-loading]) variant=outline	--xh-_action-variant-bg-hover --xh-_material-bg-hover
--xh-back-top-border	root trigger	border border-color	default disabled focus-visible variant=outline	--xh-_action-variant-border-disabled --xh-_action-variant-border-focus-visible --xh-_action-variant-border-rest --xh-_material-border
--xh-back-top-border-hover	root trigger	border-color	disabled hover is(:active, [data-pressed]) loading not([data-disabled]) not([data-loading]) pressed variant=outline	--xh-_action-variant-border-hover --xh-_action-variant-border-pressed --xh-_material-border
--xh-back-top-fg	root trigger	color	default disabled focus-visible hover is(:active, [data-pressed]) loading not([data-disabled]) not([data-loading]) pressed variant=outline	--xh-_action-variant-fg-focus-visible --xh-_action-variant-fg-hover --xh-_action-variant-fg-pressed --xh-_action-variant-fg-rest --xh-_material-fg
--xh-back-top-icon-size	trigger	--xh-icon-size	default	--xh-_back-top-glyph-size
--xh-back-top-inset-block	root	inset-block-end	default	--xh-space-6
--xh-back-top-inset-inline	root	inset-inline-end	default	--xh-space-6
--xh-back-top-layer	root	z-index	default	--xh-layer-sticky
--xh-back-top-radius	trigger	border-radius	default	--xh-_action-profile-radius
--xh-back-top-shadow	root trigger	box-shadow	default disabled focus-visible hover is(:active, [data-pressed]) is(:hover, [data-loading]) loading not([data-disabled]) not([data-loading]) pressed variant=outline	--xh-_material-shadow none
--xh-back-top-size	trigger	block-size inline-size min-inline-size	default xh-action-profile=floating	--xh-_back-top-size