import { LitElement, type PropertyValues } from 'lit';
import type { ViewportAnimationOptions, ViewportPanBehavior, ViewportPanProposal, ViewportPanSession, ViewportPoint, ViewportRect, ViewportRevealOptions, ViewportTransform, ViewportZoomProposal, ViewportZoomRequestOptions } from './viewport.types.js';
/**
 * @element nve-viewport
 * @description A viewport provides a spatial surface for arbitrary content, with optional pan and zoom navigation.
 * @documentation https://nvidia.github.io/elements/docs/elements/viewport/
 * @since 0.0.0
 * @entrypoint \@nvidia-elements/core/viewport
 * @slot - Content positioned in the viewport's infinite content space.
 * @slot background - Custom content rendered behind viewport content and excluded from content fitting
 * @slot overlay - Interactive content fixed above the transformed plane and excluded from content fitting
 * @event panstart - Dispatched when a sustained pointer or control pan begins. Cancel to suppress the default for its session.
 * @event pan - Dispatched for admitted user pan proposals. Cancel to skip the proposed transform mutation.
 * @event panend - Dispatched once when a sustained pan ends, including its terminal reason.
 * @event zoom - Dispatched for admitted user zoom proposals. Cancel to skip the proposed transform mutation.
 * @event viewportchange - Dispatched once after a render that commits one or more viewport transform changes.
 * @event capabilitieschange - Dispatched after effective user-input pan or zoom admission changes.
 * @cssprop --background - Background color of the fixed viewport area.
 * @cssprop --min-height
 * @cssprop --pan-cursor - Cursor shown over a background eligible for primary-pointer panning.
 * @cssprop --panning-cursor - Cursor shown while a pointer pan is active.
 * @command --pan-left - With behavior-pan enabled, pans left by one discrete step.
 * @command --pan-right - With behavior-pan enabled, pans right by one discrete step.
 * @command --pan-up - With behavior-pan enabled, pans up by one discrete step.
 * @command --pan-down - With behavior-pan enabled, pans down by one discrete step.
 * @command --zoom-in - With behavior-zoom enabled, animates to the next permitted scale step.
 * @command --zoom-out - With behavior-zoom enabled, animates to the previous permitted scale step.
 * @command --zoom-reset - With behavior-zoom enabled, animates to 100% scale.
 * @command --zoom-to-fit - With behavior-zoom enabled, animates to fit direct default-slot element boxes.
 * @stable false
 */
export declare class Viewport extends LitElement {
    #private;
    static styles: import("lit").CSSResult[];
    static readonly metadata: {
        tag: string;
        version: string;
    };
    /** @private */
    _internals: ElementInternals;
    private internalHost;
    constructor();
    /** Horizontal content-space coordinate at the viewport origin. */
    get x(): number;
    set x(value: number);
    /** Vertical content-space coordinate at the viewport origin. */
    get y(): number;
    set y(value: number);
    /** Content-to-viewport CSS-pixel scale. */
    get scale(): number;
    set scale(value: number);
    /** Inclusive lower scale limit. */
    get minScale(): number;
    set minScale(value: number);
    /** Inclusive upper scale limit. */
    get maxScale(): number;
    set maxScale(value: number);
    /** Enables panning by pointer, focused wheel, focused keyboard, and Invoker commands; requires Space for primary-pointer dragging when set to space. */
    get behaviorPan(): ViewportPanBehavior;
    set behaviorPan(value: ViewportPanBehavior | null | undefined);
    /** Enables zooming by pinch, focused modified wheel, focused keyboard, and Invoker commands. */
    behaviorZoom: boolean;
    /** Whether the viewport may admit new user-input panning. */
    get pannable(): boolean;
    /** Whether the viewport may admit new user-input zooming. */
    get zoomable(): boolean;
    /** Fits measurable direct default-slot content once after initial layout. */
    autoFit: boolean;
    /** Default uniform CSS-pixel inset reserved around bounds when fitting content. */
    get fitInset(): number;
    set fitInset(value: number);
    /** CSS-pixel pointer movement required before a pointer pan begins. */
    get dragThreshold(): number;
    set dragThreshold(value: number);
    connectedCallback(): void;
    disconnectedCallback(): void;
    protected updated(changed: PropertyValues<this>): void;
    render(): import("lit-html").TemplateResult<1>;
    /** Converts a content-space point to viewport CSS pixels. */
    toViewportCoords(contentX: number, contentY: number): ViewportPoint;
    /** Converts a viewport CSS-pixel point to content space. */
    toContentCoords(viewportX: number, viewportY: number): ViewportPoint;
    /** Returns the current content-space origin and CSS-pixel scale. */
    getTransform(): ViewportTransform;
    /** Returns the visible content-space rectangle. */
    getVisibleRect(): ViewportRect;
    /**
     * Requests one discrete user-originated pan. When pannable, the viewport dispatches
     * a cancelable `pan` and applies the default transform if no listener cancels the event.
     * Returns true only when that default changes the transform.
     */
    requestPan(proposal: ViewportPanProposal): boolean;
    /**
     * Requests one discrete user-originated zoom. When zoomable, the viewport dispatches
     * a cancelable `zoom` and applies the default transform if no listener cancels the event.
     * Set `options.animated` to animate the uncanceled default; the option is absent from the `zoom` detail.
     * Returns true when the default changes or schedules a change to the transform.
     */
    requestZoom(proposal: ViewportZoomProposal, options?: ViewportZoomRequestOptions): boolean;
    /**
     * Starts a sustained semantic pan after the caller crosses its activation threshold.
     * Dispatches `panstart`, performs the initial `pan` update, and returns a session for later updates
     * and one terminal `panend`. Returns undefined when pannable is false.
     */
    startPan(proposal: ViewportPanProposal): ViewportPanSession | undefined;
    /** Animates the viewport to the requested partial transform. */
    animateTo(target: Partial<ViewportTransform>, options?: ViewportAnimationOptions): void;
    /** Centers or fits a content-space region within the viewport. */
    reveal(region: {
        x: number;
        y: number;
        width?: number;
        height?: number;
    }, options?: ViewportRevealOptions): void;
    /** Fits the union of direct default-slot element boxes within the viewport. */
    fitContents(options?: ViewportRevealOptions): void;
}