/**
 * Runtime capabilities contract.
 *
 * Adapters report what the current runtime can do, and pass the report to
 * {@link processWidgetCommands}, which drops the commands that need a DOM when there is none —
 * focus, scrolling, announcing — and runs the rest.
 *
 * The check belongs at the execution point, not in a controller: a controller decides what *should*
 * happen, and whether it *can* happen is a property of the runtime doing it. A controller that
 * consulted the report itself would be claiming a guarantee it cannot keep, since nothing stops
 * another caller reaching {@link processWidgetCommands} directly.
 */
import type { MdyUiCommand } from "./commands.js";
export interface MdyWidgetRuntimeCapabilities {
    /** True when a real DOM is available. */
    readonly dom: boolean;
    /** True when the application has been hydrated. */
    readonly hydrated: boolean;
    /** True when native popover API can be used. */
    readonly popover: boolean;
    /** True when ResizeObserver is available. */
    readonly resizeObserver: boolean;
    /** True when pointer events are available. */
    readonly pointerEvents: boolean;
}
/** Runtime capabilities during SSR or non-DOM environments. */
export declare const ssrRuntimeCapabilities: MdyWidgetRuntimeCapabilities;
/**
 * Runtime capabilities of the environment this is called in.
 *
 * Every capability is probed, `dom` included. A report that asserts a DOM rather than looking for
 * one is worse than no report at all: the controller consults it precisely to decide whether a
 * command can be executed, so on a server it would be told to focus something that does not exist.
 * With no DOM the answer is {@link ssrRuntimeCapabilities} exactly.
 *
 * `hydrated` is the one dimension no global can answer — a browser that has parsed server markup
 * but not yet attached to it is indistinguishable from one that has. It follows `dom` by default,
 * which is right once the client owns the page, and a renderer that knows it is still hydrating
 * says so.
 */
export declare function browserRuntimeCapabilities(options?: {
    readonly hydrated?: boolean;
}): MdyWidgetRuntimeCapabilities;
/** Executor of UI commands produced by a controller. */
export interface MdyWidgetCommandExecutor {
    execute(commands: readonly MdyUiCommand[]): void | Promise<void>;
    destroy(): void;
}