import{type PropertyValues,type TemplateResult}from'lit';import{LyraElement}from'../../../internal/lyra-element.js';import type{LyraAppearance,LyraSize,LyraVariant}from'../../../internal/variants.js';import{type FormOwnerValue}from'../../../internal/direct-form-associated.js';import{type LyraFormValidator}from'../form-validator.js';
/** Alias of the library's one semantic-tone vocabulary, kept as an exported name so existing
*  imports of `ButtonVariant` keep resolving while `internal/variants.ts` holds the only
*  definition. */
export type ButtonVariant=LyraVariant|'default'|'primary'|'text';
/** The shared appearance vocabulary (`accent`/`filled`/`outlined`/`filled-outlined`/`plain`) plus
*  this component's two own tiers, `link` and `quiet`. */
export type ButtonAppearance=LyraAppearance|'link'|'quiet';export type ButtonType='button'|'submit'|'reset';
/** Native `formenctype` vocabulary, applied to the submission this button triggers. */
export type ButtonFormEnctype='application/x-www-form-urlencoded'|'multipart/form-data'|'text/plain';
/** Native `formmethod` vocabulary. `'dialog'` closes an ancestor `<dialog>` instead of submitting. */
export type ButtonFormMethod='get'|'post'|'dialog';export interface LyraButtonEventMap{focus:FocusEvent;blur:FocusEvent;'lr-invalid':CustomEvent<null>;}
/**
* `<lr-button>` — a generic action-button primitive. Renders an internal native
* `<button part="base">`. `type="submit"`/`type="reset"`
* are handled by this component itself via the host's associated form — a shadow-internal
* native `<button type="submit">` does not participate in an ancestor light-DOM form's submission
* on its own, since form-submitter semantics don't cross the shadow boundary.
* Submit and reset remain default actions of the composed native `click`: any listener on that
* click path can call `preventDefault()` to veto them, while stopping propagation alone does not.
* Form-level `submit`/`reset` cancellation remains a separate, later veto point.
*
* A submit button that carries `name`/`value` or any of the `form*` submission overrides
* (`formaction`/`formenctype`/`formmethod`/`formnovalidate`/`formtarget`) submits through a
* transient native `<button type="submit">` inserted directly after the host, used as
* `requestSubmit()`'s submitter and removed again in the same synchronous step. That is what makes
* the name/value pair reach the submitted `FormData` and the overrides reach the real submission:
* `requestSubmit()` can only take a submitter the form actually owns, and a custom element is never
* one. While that submitter exists it *is* the form's submitter, so `SubmitEvent.submitter` is the
* transient native button rather than this host. With none of those properties set, submission
* stays a plain `requestSubmit()` with a `null` submitter.
*
* When `href` is set to a safe link URL (`http:`/`https:`/`blob:`/`mailto:`/relative — see
* `safeLinkHref`, or `safeDownloadHref` which drops `mailto:` when `download` is set) the root
* renders as a real `<a part="base" href=…>` instead — for a link styled
* as a button (e.g. a CTA). Native navigation is then the anchor's own activation, so the
* submit/reset click handler and `type` (submit/reset) have no effect in that mode. When the
* button is disabled (its own `disabled` or an ancestor `<fieldset disabled>`) the anchor renders
* with `aria-disabled="true"` and **no `href`** — an href-less anchor is not focusable or
* navigable, so a disabled link button genuinely cannot be activated (unlike a bare
* `aria-disabled` on a still-navigable link). It also dims to `--lr-opacity-disabled` with a
* `not-allowed` cursor and drops its hover/press feedback, exactly as the native `<button>` path
* does — an `<a>` can never match the `:disabled` pseudo-class, so that arm of the disabled
* styling is keyed off `aria-disabled` instead. An unsafe/unparseable `href` falls back to the
* native `<button>`.
*
* `accessibleLabel` (attribute `aria-label`) is forwarded reactively to the internal button/anchor
* as a literal string (for an icon-only button with no visible label). Host `aria-describedby`
* IDREFs are resolved through `ariaDescribedByElements`; external `aria-labelledby` is not copied
* across the shadow boundary.
* Description targets follow same-ID replacement, removal, reinsertion, reconnection and document
* adoption, including transitions between the native button and anchor.
* Host `aria-haspopup` and `aria-expanded` values are likewise forwarded to the internal semantic
* control. `aria-pressed` (`true`, `false`, `mixed`) supports button toggles; `aria-current`
* (`page`, `step`, `location`, `date`, `time`, `true`, `false`) supports current navigation.
* These states follow attribute changes, removal and button/link replacement without changing
* the native role. Empty or unsupported state tokens are omitted from the internal control.
* When host `aria-controls` names elements in the host's own root, the controls
* relationship is resolved onto the internal control through the reflected element-reference API
* so it remains valid across this component's shadow boundary. Assigning that relationship
* intentionally clears the serialized `aria-controls` value; read `ariaControlsElements` in a
* supporting browser. Browsers without that API retain the forwarded string attribute as a
* best-effort fallback.
* Circle and automatically detected icon-only buttons keep the shared
* `--lr-icon-button-size` minimum target in every `size` tier; the tier still scales their glyph
* and chrome, but cannot collapse the clickable box below that floor.
* In a constrained row the default-slot label ellipsizes (set `wrap` for a multi-line label
* instead), while each `start`/`end` adornment is capped at 40% of the control so unbroken
* consumer content cannot force the button wider.
* The label does **not** grow to fill a stretched button: icon and label centre together under
* `--lr-button-justify`. A `with-caret` button, and one with an `end`/`suffix` adornment, keep the
* old growing label so that trailing affordance stays pinned to the trailing content edge;
* `--lr-button-label-grow` overrides both directions.
*
* @customElement lr-button
* @event focus - Native focus relayed once from the internal button or anchor.
* @event blur - Native blur relayed once from the internal button or anchor.
* @event lr-invalid - The button failed a validity check. Cancelable; preventing it also prevents
*   the native `invalid` event's default validation UI.
* @slot - Default slot: the button's label content.
* @slot start - Leading icon/content, rendered before the label.
* @slot prefix - Shoelace alias for `start`, rendered through the same wrapper.
* @slot end - Trailing icon/content, rendered after the label.
* @slot suffix - Shoelace alias for `end`, rendered through the same wrapper.
* @attr form - ID of an external form owner. The `form` property still reads as the resolved form.
* @attr aria-pressed - Toggle state forwarded reactively to the internal control: true, false or mixed.
* @attr aria-current - Current-item state forwarded reactively to the internal control: page, step, location, date, time, true or false.
* @attr rel - Independently settable author relationship tokens (no default). `opener` is always
*   stripped, and any `target` force-adds the non-removable `noopener noreferrer` guard.
* @csspart base - Compatibility name for the internal control; use `button`.
* @csspart button - The internal native `<button>` (or an `<a>` for a safe link). It is the same
*   node as `base`. Circle and icon-only states retain the shared minimum icon-button target.
* @csspart label - The default-slot label wrapper.
* @csspart start - The `start` slot wrapper.
* @csspart prefix - Shoelace alias for `start`; both names are on the same wrapper.
* @csspart end - The `end` slot wrapper.
* @csspart suffix - Shoelace alias for `end`; both names are on the same wrapper.
* @csspart caret - The decorative dropdown chevron, present only while `withCaret` is `true`.
* @csspart spinner - The loading spinner, present only while `loading` is `true`.
* @cssprop [--lr-button-width=100%] - Inline size of the internal button. The host
* defaults it to `100%` so the native button follows the host's own width; override to
* `auto` (or any other value) for a compact inline composition.
* @cssprop [--lr-button-hover-base=var(--lr-color-surface)] - The colour the hover and press
* mixes move away from. Each painted appearance re-points it at its own fill
* (`--lr-button-fill` for `filled`/`filled-outlined`, `--lr-button-accent-fill` for `accent`); the
* chrome-less tiers (`outlined`, `plain`, `quiet`, `link`) paint nothing, so they mix from the page
* surface. Set it alongside `--lr-button-outlined-fill` when you tint an outlined button.
* @cssprop [--lr-button-hover-background=color-mix(in oklab, var(--lr-button-hover-base), var(--lr-color-mix-partner) var(--lr-color-mix-hover))] -
* Background of a non-disabled button while hovered. Replaced the pre-8.0.0
* `--lr-button-hover-brightness` multiplier: a `filter` multiplies every channel, so it moved a
* mid-toned fill but did nothing at all to a pure white or pure black one, and it dimmed the label
* and icons along with the box.
* @cssprop [--lr-button-active-background=color-mix(in oklab, var(--lr-button-hover-base), var(--lr-color-mix-partner) var(--lr-color-mix-active))] -
* Background while a non-disabled button is pressed — the same mix at the stronger
* `--lr-color-mix-active` share, so the pressed state reads as more than the hover.
* `appearance="link"` moves its text colour by these two shares instead of taking a background.
* @cssprop --lr-button-hover-color - Text color of a non-disabled button while hovered.
* **Undeclared by default**, so it falls back to whatever colour the active `appearance` already
* paints at rest — every appearance's current hover text colour is unchanged until this is set.
* `appearance="link"` ignores it: its own hover rule sets a higher-specificity colour mix instead.
* @cssprop --lr-button-hover-border - Border color of a non-disabled button while hovered.
* **Undeclared by default**, so it falls back to whatever border colour the active `appearance`
* already paints at rest — every appearance's current hover border is unchanged until this is set.
* `appearance="link"` renders with no border (`border: 0`) at every state, so this has no visible
* effect there.
* @cssprop [--lr-button-active-scale=0.9875] - `transform: scale()` factor applied while a
* non-disabled button is pressed.
* @cssprop [--lr-button-spinner-duration=var(--lr-transition-ambient)] - Timing of the `loading` spinner.
* @cssprop [--lr-button-accent=var(--lr-color-fill-loud)] - Text/glyph color for the chrome-less
* appearances (`outlined`, `plain`, `link`), i.e. the active `variant`'s loud fill used as a
* foreground. `variant="neutral"` is the one exception: its loud fill is a mid grey picked to carry
* light text, so borrowing it as text on the page surface would wash out every plain and link
* button — neutral keeps `--lr-color-text`.
* @cssprop [--lr-button-fill=var(--lr-color-fill-quiet)] - Background of `appearance="filled"`:
* the active `variant`'s quiet tint, i.e. a secondary-action fill that is visibly a fill rather
* than the page surface. Follows `variant` through the shared semantic grid.
* @cssprop [--lr-button-on-fill=var(--lr-color-on-quiet)] - Text color on top of
* `--lr-button-fill`, the grid's guaranteed-legible foreground for that tint.
* @cssprop [--lr-button-accent-fill=var(--lr-color-fill-loud)] - Background of
* `appearance="accent"` (and its border color): the active `variant`'s loud fill, the one primary
* action in a view.
* @cssprop [--lr-button-accent-on-fill=var(--lr-color-on-loud)] - Text color on top of
* `--lr-button-accent-fill`, the grid's guaranteed-legible foreground for that fill.
* @cssprop [--lr-button-border=var(--lr-color-border-normal)] - Border color of the internal
* button, from the active `variant`'s row of the shared semantic grid.
* @cssprop [--lr-button-outlined-border=var(--lr-color-border-strong)] - Border color of
* `appearance="outlined"` and `appearance="filled-outlined"`, which overrides `--lr-button-border`.
* @cssprop [--lr-button-outlined-fill=transparent] - Background of `appearance="outlined"`.
* Transparent by default; set it to tint the button (e.g. a faint surface wash behind the outline)
* without a `::part(base)` rule. Like `--lr-button-quiet-*`, it is deliberately *not* swapped per
* `variant`. The hover and press mixes read `--lr-button-hover-base`, which this tier leaves on the
* page surface, so set both together when you tint an outlined button.
* @cssprop [--lr-button-quiet-border=var(--lr-color-border)] - Border color of
* `appearance="quiet"`.
* @cssprop [--lr-button-quiet-text=var(--lr-color-text-quiet)] - Text color of
* `appearance="quiet"`.
* @cssprop [--lr-button-size-2xs=var(--lr-form-control-height-2xs)] - `min-block-size` at
* `size="2xs"`. Since 8.0.0 the whole scale comes from the shared form-control ladder
* (`internal/sizes.styles.ts`), so ordinary single-row controls share the same minimum-height
* floor. A composed control can still grow to preserve an action's hit target or fit its content.
* @cssprop [--lr-button-size-xs=var(--lr-form-control-height-xs)] - `min-block-size` at `size="xs"`.
* @cssprop [--lr-button-size-s=var(--lr-form-control-height-s)] - `min-block-size` at `size="s"`
* (and at the `size="small"` spelling).
* @cssprop [--lr-button-size-m=var(--lr-form-control-height-m)] - `min-block-size` at `size="m"`
* (and at `size="medium"`), the default tier.
* @cssprop [--lr-button-size-l=var(--lr-form-control-height-l)] - `min-block-size` at `size="l"`
* (and at `size="large"`).
* @cssprop [--lr-button-size-xl=var(--lr-form-control-height-xl)] - `min-block-size` at `size="xl"`.
* @cssprop [--lr-button-padding-block=var(--lr-form-control-padding-block)] - Block padding of the
* internal button, taken from the active `size` tier of the shared ladder. Override it to retune a
* tier without a `::part(base)` rule; `appearance="link"` ignores it (it renders with zero padding).
* @cssprop [--lr-button-padding-inline=var(--lr-form-control-padding-inline)] - Inline padding of
* the internal button, from the active `size` tier. `appearance="link"` ignores it.
* @cssprop [--lr-button-font-size=var(--lr-form-control-font-size)] - Font size of the internal
* button, from the active `size` tier. `appearance="link"` ignores it and inherits the ambient font
* instead.
* @cssprop [--lr-button-min-height=var(--lr-form-control-height)] - The active tier's
* `min-block-size` floor, resolved through that tier's own `--lr-button-size-*` token, and used as
* the fallback when `--lr-button-height` is unset.
* @cssprop --lr-button-height - Exact height of the internal button. **Undeclared by default** — so
* the button keeps the active tier's `min-block-size` floor and an `auto` height, exactly as
* before. Set it (e.g. to pin the button to a fixed toolbar row) to both floor *and* cap the
* height. Never declare it as `auto`: a declared value wins over the `var()` fallback arm and would
* make every tier's floor dead code. `appearance="link"` ignores it.
* @cssprop [--lr-button-gap=var(--lr-form-control-gap)] - Gap between the icon/label and any
* slotted content in the internal button. Constant across the ladder's tiers. Override it to retune
* without a `::part(base)` rule.
* @cssprop [--lr-button-justify=center] - `justify-content` of the internal button's row. With the
* label no longer growing by default, this is what positions the whole icon+label pair inside a
* stretched control: `flex-start` packs it against the leading edge, `space-between` pushes the
* adornments apart.
* @cssprop [--lr-button-label-grow=0] - `flex-grow` of `[part="label"]`. `0` (the default) lets the
* label shrink-wrap its text so `--lr-button-justify` positions the real content; `1` restores the
* pre-16.0.0 behaviour where the label absorbed every spare pixel of a stretched button. It also
* overrides the automatic grow a `with-caret`/`end`-adornment button applies, so `0` opts those
* rows out of pinning their trailing affordance.
* @cssprop [--lr-button-radius=var(--lr-form-control-radius)] - Corner radius of the internal
* button, from the active `size` tier of the shared ladder (the two tightest tiers take a smaller
* radius, since a 6px corner on a 20px-tall control reads as a lozenge). `appearance="link"`
* ignores it (it renders with zero radius). `pill` changes the private default to
* `--lr-radius-pill`; an inherited or direct `--lr-button-radius` still wins.
* @cssprop [--lr-button-caret-size=var(--lr-size-0-75em)] - Font size of the `with-caret` chevron,
* i.e. its rendered glyph box. Relative to the button's own font size, so it follows every `size`
* tier without a per-tier rule.
* @cssprop --lr-button-shadow - Box shadow of the internal button. **Undeclared by default**, so
* `box-shadow` falls back to `none` — byte-identical to before this property existed. Set it (e.g.
* an elevated/floating action button) without a `::part(base)` rule. `appearance="link"` always
* renders with no shadow regardless of this token — a zero-chrome inline link has no box to elevate.
* @cssstate disabled - The button is disabled directly, by a fieldset, or by `loading`.
* @cssstate icon-button - The default slot contains one icon-like element and no visible text. A
* visually hidden label (`<lr-visually-hidden>`, `hidden`/`display: none`/`visibility: hidden`, or
* the standard absolutely-positioned `clip-path: inset(50%)` algorithm) does not count as content,
* so the recommended icon-plus-screen-reader-name shape still gets the square treatment.
* @cssstate link - A safe `href` currently renders the native anchor mode.
* @cssstate loading - The button is showing its loading spinner.
* @status stable
* @since 4.0.0
*/
export declare class LyraButton extends LyraElement<LyraButtonEventMap>{
/** Public WA-compatible intrinsic validator catalog. */
static get validators():LyraFormValidator<LyraButton>[];static styles:import("lit").CSSResultGroup[];static formAssociated:boolean;static properties:{disabled:{type:BooleanConstructor;reflect:boolean;noAccessor:boolean;};name:{reflect:boolean;noAccessor:boolean;converter:import("lit").ComplexAttributeConverter<string,unknown>;};customError:{attribute:string;reflect:boolean;noAccessor:boolean;};};private _fieldsetDisabled;private _disabled;private _name;private _value;private _required;private _variant;private readonly localDescriptionIds;private externalDescriptionLease?;private internals;private validityController;
/** Consumer validity retained while a non-action mode is barred from validation. */
private customValidityMessage;private reflectingCustomError;
/** Consumer-supplied validation message reflected through `custom-error`.
* @default null */
customError:string|null;get disabled():boolean;set disabled(next:boolean);
/** Submitted as a `name`/`value` pair with the form data, but only while this button is the
*  submitter (`type="submit"`, in `<button>` mode). Unnamed (the default), the button contributes
*  nothing — exactly like a native `<button>` with no `name`. See the class doc comment for how
*  the pair reaches the submitted `FormData`.
*
*  Reflected synchronously on assignment (rather than on Lit's async update cycle) because a
*  rename must be visible to a `form.requestSubmit()` in the same tick — including this
*  component's own, when a consumer renames the button from the click handler that submits. */
get name():string;set name(next:string|null);
/** Whether the button is disabled explicitly or by an ancestor fieldset. */
get effectiveDisabled():boolean;
/** Browser-resolved form owner; assigning an ID, form element, or `null` updates `form`. */
get form():HTMLFormElement|null;set form(owner:FormOwnerValue);getForm():HTMLFormElement|null;get labels():NodeList;get validity():ValidityState;get validationMessage():string;get willValidate():boolean;constructor();
/** Accessible name forwarded to the internal native button or anchor. Bound to the host's
*  `aria-label` content attribute so changing or removing that attribute after mount keeps the
*  actual focused control synchronized. */
accessibleLabel:string|null;private triggerHasPopup;private triggerExpanded;private triggerPressed;private triggerCurrent;private triggerControls;private triggerDescribedBy;
/** Semantic tone, from the library's one `variant` vocabulary — the same five values every other
*  `variant` in the library takes. Selects which row of the semantic colour grid every fill,
*  border and foreground token below resolves against. Shoelace's `default`/`primary` spellings
*  normalize to `neutral`/`brand`; its `text` spelling normalizes to neutral `appearance="plain"`.
*  Reads always return the canonical Lyra vocabulary.
* @default neutral */
get variant():ButtonVariant;set variant(next:ButtonVariant);
/** `'accent'` (the default, matching the upstream default) is the loud tier: the active
*  `variant`'s solid fill with its guaranteed-legible foreground, for the one primary action in a
*  view. `'filled'` is the same tone one emphasis step down — a quiet tint, for a secondary
*  action; it is deliberately a real fill rather than the page surface, so the two tiers never
*  paint the same button. `'outlined'` is a border with no fill, `'plain'` neither.
*  `'filled-outlined'` is `'filled'` plus `'outlined'`'s border color, for a filled button that
*  still has to read against a same-toned surface.
*  `'link'` is zero-chrome inline text — no padding, border, or
*  min-height, underlined, colored from `--lr-button-accent` (the same token `'plain'` uses)
*  and inheriting the surrounding font — for a text link that flows inline in a sentence rather
*  than a button-shaped control. `'quiet'` is a bordered, transparent-until-hover tier for a
*  toolbar-style icon+label action — its border/text read fixed `--lr-color-border`/`--lr-color-text-quiet`
*  tokens regardless of `variant`, unlike `'outlined'`'s variant-tinted text, so it stays
*  visually muted at rest. */
appearance:ButtonAppearance;
/** Visual size on the library's one control ladder. Accepts both the canonical `'2xs'`–`'xl'`
*  steps and Web Awesome's/Shoelace's `'small'`/`'medium'`/`'large'` spellings of `s`/`m`/`l`, so
*  a migration is a tag rename with no attribute rewrite; the two spellings render identically.
*  `'2xs'` is the tightest tier — a sub-`xs` size for dense, toolbar-embedded controls (e.g.
*  beside a native `<input type="search">` in a compact dialog header). `'m'` (the default) is
*  the standard size. */
size:LyraSize;
/** Fully rounded ends, for a pill-shaped control. Changes the private radius default to
*  `--lr-radius-pill` rather than declaring a radius on `[part~="base"]`, so an inherited or
*  direct `--lr-button-radius` stays authoritative. `appearance="link"` still renders with zero
*  chrome, pill or not. */
pill:boolean;
/** Shoelace-compatible circular icon-button treatment. It does not replace `pill`: `circle`
*  additionally makes the control square and removes label-oriented inline padding. */
circle:boolean;
/** Shoelace-compatible outlined treatment. The canonical `appearance` property remains
*  untouched so removing `outline` restores the exact Lyra appearance the author selected. */
outline:boolean;
/** Renders a decorative trailing chevron (`[part="caret"]`, `aria-hidden`) marking the button as
*  a dropdown/menu trigger. It carries no accessible name of its own — the button's label already
*  names the action, and the popup relationship is expressed by a host `aria-haspopup`/
*  `aria-expanded`, which are forwarded to the internal control. */
withCaret:boolean;
/** Reflected Shoelace alias for `withCaret`; both attributes reach the same rendered chevron.
* @default false */
get caret():boolean;set caret(next:boolean);
/** SSR presence hint for the `start` adornment wrapper. Assigned slot content is still detected
*  automatically, so this is optional in client-rendered markup. */
withStart:boolean;
/** SSR presence hint for the `end` adornment wrapper. */
withEnd:boolean;
/** Wraps a long label onto multiple lines instead of ellipsis-truncating it to one, matching
*  `<lr-chip>`'s identical opt-in. `false` (the default) reproduces the exact single-line,
*  ellipsis-truncated `[part="label"]`. */
wrap:boolean;
/** Forwarded to this component's own submit/reset handling — see the class doc comment above
*  for why this component (not the shadow-internal `<button>`) owns that behavior. */
type:ButtonType;
/** The value submitted alongside `name`. Meaningful only together with a `name`, matching a
*  native submit button. */
/**
* @default ''
*/
get value():string;set value(next:string);
/** Whether a non-empty submitter value is required. This adds the Web Awesome form-control
*  contract without making an ordinary optional action button contribute persistent form data.
* @default false */
get required():boolean;set required(next:boolean);
/** Overrides the form owner's `action` for the submission this button triggers. Unset by
*  default, leaving the form's own `action` in place. */
formAction?:string;
/** Overrides the form owner's `enctype` for the submission this button triggers. */
formEnctype?:ButtonFormEnctype;
/** Overrides the form owner's `method` for the submission this button triggers. */
formMethod?:ButtonFormMethod;
/** Skips the form owner's constraint validation for the submission this button triggers —
*  the native `formnovalidate` semantics. Without it an invalid form is reported and not
*  submitted, exactly as a native submit button behaves. */
formNoValidate:boolean;
/** Overrides the form owner's `target` for the submission this button triggers. Distinct from
*  `target`, which is the anchor target used in link mode. */
formTarget?:string;
/** Shows an internal spinner in place of interaction affordance and disables the button, without
*  clearing `disabled` — a consumer's own `disabled` state and a transient `loading` state are
*  independent (mirrors `<lr-export-button>`'s own `loading`/`disabled` pair). */
loading:boolean;
/** When set to a safe link URL, the button's root renders as a real `<a href=…>` instead of a
*  `<button>` — for a link styled as a button (e.g. a CTA). Unset (the default) renders a plain
*  `<button>`, byte-for-byte as before. Only `http:`/`https:`/`blob:`/`mailto:`/relative URLs are
*  honored (see `safeLinkHref`); an unsafe/unparseable value falls back to the native `<button>`.
*  Setting `download` narrows the allowlist to `safeDownloadHref`'s, which drops `mailto:` — a
*  mail handoff names no retrievable bytes, so it cannot be a download target.
*  `type` (submit/reset) has no effect while the anchor renders — an anchor has no submit/reset
*  concept, and native navigation is its own activation. While the button is disabled the anchor
*  renders with no `href` (see the class doc comment), so a disabled link button cannot navigate. */
href?:string;
/** Native anchor `target`, used only while `href` resolves to a link. Setting this to `'_blank'`
*  (or any other target) always contributes `noopener noreferrer` to the rendered anchor's `rel`
*  — matching `lr-card`'s/`lr-stat`'s identical pattern. Author `rel` tokens are merged rather
*  than ignored (see `rel`), but the guard is not removable and `opener` is always stripped.
*  Ignored in `<button>` mode. */
target?:string;
/** Author-settable link relationship, merged with a non-negotiable security floor.
*
*  Mirrors `wa-button`/`sl-button`'s `rel`, so values the platform defines and upstream consumers
*  actually use -- `nofollow`, `me`, `license`, `external`, `tag` -- survive a `wa-`/`sl-` -> `lr-`
*  rename instead of being silently dropped. Two rules are enforced regardless of what an author
*  writes, which is what keeps this safe to expose:
*
*  1. `opener` is always stripped. It is the one token that re-opens the reverse-tabnabbing vector.
*  2. Whenever `target` is set, `noopener noreferrer` is force-added. A named/new browsing context
*     always gets the guard, author input or not.
*
*  With no `target` there is no new browsing context to protect, so a same-tab link renders exactly
*  the author's tokens. Deliberately left with NO default: `wa-button` declares none, and defaulting
*  it (as `sl-button` does) would start suppressing the `Referer` header on every same-tab Lyra
*  link -- a real behavior change well beyond parity. */
rel?:string;
/** Resolved `rel` for the rendered anchor: author tokens minus `opener`, plus the
*  `noopener noreferrer` guard whenever `target` is set. `undefined` when nothing remains, so the
*  attribute is omitted rather than rendered empty. */
private get resolvedRel();
/** Native anchor `download` attribute, used only while `href` resolves to a link. Ignored in
*  `<button>` mode. */
download?:string;
/** Whether the `start`/`end` slots have assigned content. Drives `?hidden` on the adornment
*  wrappers so an unslotted wrapper collapses to `display: none` instead of contributing a dead
*  `--lr-button-gap` of inline space (a bare `<slot>` is an element child, so a `:empty` rule
*  could never match it). Seeded synchronously in `willUpdate` before the first paint, then kept
*  current by each slot's `slotchange` — mirrors `<lr-input>`'s identical pattern. */
private hasStartSlot;private hasEndSlot;
/** Whether the default slot's visible content is a single icon-like element (see
*  `hasIconOnlyDefaultContent()`). Seeded synchronously in `willUpdate` before the first paint,
*  then kept current by the default slot's own `slotchange` for a DOM mutation AND by
*  `resizeObserver` below for a CSS-only visibility flip (a container/media query hiding or
*  revealing a slotted label) that mutates no DOM at all and so fires no `slotchange`. */
private isIconButton;
/** Watches `labelEl` -- the internal default-slot wrapper, never the host or `baseEl` -- so a
*  consumer's CSS-only rule (a container/media query hiding the visible label at a narrow width,
*  with no accompanying DOM mutation) still re-evaluates `isIconButton`. `slotchange` only fires
*  on a DOM mutation, and there is no `matchMedia` here bound to a breakpoint this component
*  doesn't know about, so a resize of the element that actually wraps the label is the
*  mechanism-agnostic signal a vanishing/returning label produces. Deliberately NOT the host or
*  `baseEl`: once `isIconButton` is `true`, `[part~='base'][data-icon-button]` gives `baseEl` (and
*  therefore the content-sized host) a fixed, definite `inline-size` that no longer depends on the
*  label at all -- watching either one would report a resize on the way IN, then never resize
*  again on the way back out no matter how much wider the label's own container becomes,
*  permanently wedging the button in icon-only mode. `labelEl`'s own box is never touched by
*  `data-icon-button`, so it keeps tracking the label's actual rendered presence in both
*  directions. Armed once `labelEl` exists (from `updated()`, and from a reconnect's
*  `connectedCallback`), torn down in `disconnectedCallback`. */
private resizeObserver?;
/** The pending "commit the recompute" animation-frame token armIconOnlyResizeObserver() schedules,
*  and the window that owns it -- both cleared in `disconnectedCallback` so a frame callback never
*  fires against a torn-down or reparented host. */
private iconOnlyResizeRaf?;private iconOnlyResizeRafOwner?;private baseEl?;private labelEl?;
/** Activates the internal base element. In `<button>` mode this also runs the component's
*  submit/reset behavior (via the button's own `@click`); in anchor mode it triggers native
*  navigation (the anchor has no `@click` handler of its own). Disabled and loading buttons
*  remain inert in both modes. */
click():void;focus(options?:FocusOptions):void;blur():void;checkValidity():boolean;reportValidity():boolean;
/** Sets or clears a consumer-supplied validation error without disturbing `required`. */
setCustomValidity(message:string):void;
/** Clears consumer custom validity and republishes the current intrinsic constraint. */
resetValidity():void;
/** Restores the submitter value used by session history/autofill without making it a persistent
*  form-data entry; it is still contributed only while this control is the submitter. */
formStateRestoreCallback(state:string|File|FormData|null,reason:'autocomplete'|'restore'):void;
/** Runs the form action after every listener on the composed click path had its veto turn. */
private runClickDefaultAction;private onClick;private onFocus;private onBlur;
/** Whether anything about this button changes the submission itself, rather than merely
*  triggering it. Only then is the transient native submitter worth creating: with none of these
*  set, a plain `requestSubmit()` keeps `SubmitEvent.submitter` `null` as before. */
private get hasSubmitterOverrides();
/**
* Submits `form` through a transient native `<button type="submit">` carrying this button's
* `name`/`value` and `form*` overrides.
*
* `requestSubmit(submitter)` refuses any submitter the form doesn't own, and a custom element can
* never be one, so neither the name/value pair nor the overrides can reach the submission from
* the host itself — `internals.setFormValue()` wouldn't help either, since a submitter's pair is
* contributed by the submission algorithm, not by the control's form value. The stand-in is
* inserted directly after the host so its pair lands in the entry list in the same tree-order
* position a native submit button would, and removed in a `finally` so a throwing or
* validation-blocked submission can't leave it behind.
*/
private submitAsNamedSubmitter;
/**
* Called by the browser when an ancestor `<fieldset disabled>` toggles. Tracked separately
* from the consumer's own `disabled` (see `effectiveDisabled`) so a consumer's explicit
* `disabled` survives the fieldset re-enabling instead of being permanently overwritten --
* mirrors `<lr-checkbox>`'s/`<lr-switch>`'s identical `_fieldsetDisabled` pattern.
*/
formDisabledCallback(disabled:boolean):void;connectedCallback():void;disconnectedCallback():void;adoptedCallback():void;protected willUpdate(changed:PropertyValues):void;private syncAdornmentSlots;private onStartSlotChange;private onEndSlotChange;private hasIconOnlyDefaultContent;private onDefaultSlotChange;
/** Starts watching `labelEl`, unless already watching, `labelEl` doesn't exist yet (true before
*  the first render), or the realm provides no `ResizeObserver` at all (absent under SSR).
*  Idempotent -- safe to call from every `updated()` and from a reconnect's `connectedCallback`. */
private armIconOnlyResizeObserver;
/** Whether the label takes the row's slack so a trailing affordance stays pinned to the trailing
*  content edge. Exactly the caret and the `end`/`suffix` adornment qualify: both read as
*  detached glyphs when they float mid-row. A plain button (or one with only a `start`
*  adornment) centres its content instead. */
private get labelGrows();protected updated(changed:PropertyValues):void;private updateValidity;
/** Disabled/loading controls and a link-rendering button are not form actions. */
private get isValidationBarred();private syncButtonStates;private syncDescribedByElements;private releaseExternalDescription;render():TemplateResult;}declare global{interface HTMLElementTagNameMap{'lr-button':LyraButton;}}