/**
 * Button-state concern — all `apply*` helpers that update button icons,
 * aria-labels, and visual state in response to player events.
 *
 * Integration: each helper receives only the DOM refs it touches and any
 * scalar values it needs. No plugin instance is passed; these are pure DOM
 * mutations driven by event data that the plugin class hands in.
 */
import type { ITranslator } from '@nomercy-entertainment/nomercy-player-core';
import type { IVideoPlayer, VideoPlaylistItem } from '../../../index.js';
/** Sync the volume slider value and CSS custom property. `volume` is 0-100 (kit scale). */
export declare function applyVolume(volSlider: HTMLInputElement, applyMutedIconFn: () => void, volume: number): void;
/** Toggle the muted CSS class on the volume button. */
export declare function applyMuted(volBtn: HTMLButtonElement, applyMutedIconFn: () => void, muted: boolean): void;
/** Update the volume button icon and aria-label to reflect current mute + level. */
export declare function applyMutedIcon(volBtn: HTMLButtonElement, player: IVideoPlayer<VideoPlaylistItem>, translate: ITranslator['t']): void;
/**
 * Update the speed button icon and aria-label.
 * Adds `is-active` when `rate` diverges from the default (1), which forces the
 * filled icon variant via the CSS `.btn.is-active` rule.
 * The aria-label appends the current rate when it is non-default so screen-reader
 * users know the active speed without opening the menu.
 */
export declare function applyRate(speedBtn: HTMLButtonElement, rate: number, translate: ITranslator['t']): void;
/**
 * Update the quality button icon, `is-active` class, and aria-label.
 * `isManual` is true when the user has pinned a specific quality level (not
 * auto). A manual quality selection is a non-default state that should be
 * indicated via `is-active` — matching the pattern used by aspect, pip, and speed.
 * The aria-label includes the playing level when known.
 */
export declare function applyQualityIcon(qualityBtn: HTMLButtonElement, translate: ITranslator['t'], playingLabel?: string, isManual?: boolean): void;
/** Sync the fullscreen button icon to the current fullscreen state. */
export declare function applyFullscreen(fsBtn: HTMLButtonElement): void;
/** Update the theater button icon and aria-label. */
export declare function applyTheaterIcon(theaterBtn: HTMLButtonElement, active: boolean, translate: ITranslator['t']): void;
/**
 * Toggle subtitles button between the on/off icon AND the `is-active` class
 * based on the active track index. An active subtitle track (index >= 0) is
 * non-default, so both the filled icon and `is-active` are applied together.
 */
export declare function applySubsIcon(subsBtn: HTMLButtonElement, activeSubtitleIdx: number | null, translate: ITranslator['t']): void;
/**
 * Update the PiP button icon, `is-active` class, and aria-label.
 * PiP engaged is a non-default state, so `is-active` is added alongside the
 * exit-pip icon — matching the aspect-ratio and speed pattern exactly.
 */
export declare function applyPipIcon(pipBtn: HTMLButtonElement, active: boolean, translate: ITranslator['t']): void;
/**
 * Update the audio button icon, `is-active` class, and aria-label.
 * `isNonDefault` is true when the playing track is not the manifest's default
 * track (index 0 / default flag). A non-default audio selection is a changed
 * state and should be indicated — matching the pattern used by subtitle, aspect,
 * pip, and speed.
 */
export declare function applyAudioIcon(audioBtn: HTMLButtonElement, translate: ITranslator['t'], isNonDefault?: boolean): void;
/**
 * Update the aspect-ratio button icon and aria-label. The hover tooltip is owned by `addTooltip()`.
 * Adds `is-active` when the aspect diverges from the default (`'uniform'`), which forces the
 * filled icon variant via the CSS `.btn.is-active` rule.
 */
export declare function applyAspectRatioIcon(aspectRatioBtn: HTMLButtonElement, isDefault: boolean, translate: ITranslator['t']): void;