import { noChange, nothing, TemplateResult } from 'lit-html/lit-html.js';
export * from 'lit-html/lit-html.js';
export * from './lib/add-pending-task.js';
export * from './lib/css-tag.js';
export declare type Constructor<T = {}> = new (...args: any[]) => T;
export declare type WidgetAnimation = {
  readonly keyframes: Keyframe[];
  readonly options?: KeyframeAnimationOptions;
} | null;
export declare type WidgetAttributeType = 'string' | 'number' | 'boolean';
export declare type WidgetTemplate =
  | TemplateResult
  | string
  | number
  | typeof nothing
  | typeof noChange;
export declare type WidgetReactives<T extends typeof Nexwidget> =
  (keyof T['prototype'] & string)[];
export declare type WidgetAttributes<T extends typeof Nexwidget> = {
  readonly key: keyof T['prototype'] & string;
  readonly type: WidgetAttributeType;
}[];
export declare class Nexwidget extends HTMLElement {
  #private;
  static get styles(): CSSStyleSheet[];
  static get reactives(): string[];
  static get attributes(): string[];
  static get propertyKeysForObservedAttributes(): string[];
  static get observedAttributes(): string[];
  static registerAs<
    T extends typeof Nexwidget,
    K extends keyof HTMLElementTagNameMap,
  >(this: T & (new () => HTMLElementTagNameMap[K]), tagName: K): void;
  static createReactives<T extends typeof Nexwidget>(
    this: T,
    reactives: WidgetReactives<T>,
  ): void;
  static createAttributes<T extends typeof Nexwidget>(
    this: T,
    attributes: WidgetAttributes<T>,
  ): void;
  get removedSignal(): AbortSignal | undefined;
  get unmountedSignal(): AbortSignal | undefined;
  get template(): WidgetTemplate;
  get mountAnimation(): WidgetAnimation;
  get updateOrSlotChangeAnimation(): WidgetAnimation;
  get usesNexwidget(): true;
  getCSSProperty(key: string): string;
  attributeChangedCallback(
    _key: string,
    oldValue: string,
    newValue: string,
  ): void;
  connectedCallback(): void;
  disconnectedCallback(): void;
  addedCallback(): void;
  updatedCallback(): void;
  slotChangedCallback(): void;
  mountedCallback(): void;
  removedCallback(): void;
  unmountedCallback(): void;
}