/**
 * The relation between an overlay's opener and the overlay it opens.
 *
 * A function of kind, widget id and open-ness alone — no controller, no widget state — so a renderer
 * can bind it without building the machinery that produces the rest of a kind's projection. The
 * kind-specific projections call it too, which is what keeps one answer to a relation that appears
 * on six kinds and three adapters.
 */
import { type MdyWidgetKind } from "./catalog.js";
import type { MdyPartContract } from "./contract.js";
export interface MdyOverlayOpenerA11yOptions {
    readonly widgetId: string;
    /** Whether the overlay is showing. */
    readonly open: boolean;
    /**
     * Whether the element the opener controls is in the document.
     *
     * Not the same question as `open`: a renderer that builds its popup eagerly keeps it mounted and
     * hidden while closed, and one that builds it on demand has nothing to point at until it does.
     * `aria-controls` naming an id that resolves to nothing is a dangling reference, which assistive
     * technology cannot follow and which no amount of correct `aria-expanded` makes up for.
     *
     * Defaults to true — an eagerly-mounted popup, which is what every caller assumed before this
     * existed.
     */
    readonly controlsRendered?: boolean;
}
/**
 * The attributes an overlay's opener carries, or `null` for a kind with no overlay.
 *
 * `aria-expanded` is a string in both states rather than an attribute that comes and goes: it is a
 * property of the opener, and an opener that drops it while closed reads as a control with no
 * overlay at all.
 */
export declare function projectOverlayOpenerA11y(kind: MdyWidgetKind, options: MdyOverlayOpenerA11yOptions): MdyPartContract | null;
/** The id the opener names, for a renderer that has to put it on the controlled element. */
export declare function overlayControlledId(kind: MdyWidgetKind, widgetId: string): string | null;
/**
 * Whether focus is still inside a field, given where it went.
 *
 * A field's focus has left when it has left the control **and** is not inside the panel the control
 * opened. Where that panel lives in the document is a rendering decision — taken for clipping
 * reasons, so a list is not cut off by a scrolling ancestor — and a rendering decision must not
 * reach behaviour. A renderer that answers by containment says focus left the moment it entered a
 * panel drawn elsewhere; a renderer that draws its panel in place says it did not. Same contract,
 * two behaviours, decided by where a `<div>` was appended.
 *
 * So the scope follows the link the opener declares: `aria-controls` names the element, and that
 * element and everything inside it belongs to the field wherever it is drawn. ADR 0167.
 *
 * `null` — focus went nowhere at all — is not a leaving here and is deliberately the caller's
 * question: re-rendering an element removes whatever was focused and blurs it into nowhere, and a
 * calendar cell replaced when the view changes must not read as somebody walking out of the field.
 */
export declare function focusIsInsideField(root: Element, node: Node | null): boolean;