export interface ViewTransitionControllerOptions {
	/** The document whose `startViewTransition` should be used. */
	document?: Document;
	/** Whether view transitions are enabled for this viewer. */
	enabled: boolean;
}
/**
* `document.startViewTransition` wrapper (#12). Runs the given
* update callback inside a view transition, waiting for the DOM
* mutation to commit before invoking the `afterUpdate` hook and
* then awaiting the full animation. Degrades gracefully to an
* instant update on engines without support.
*/
export declare class ViewTransitionController {
	private readonly enabled;
	private readonly doc;
	constructor(options: ViewTransitionControllerOptions);
	/** Whether the host environment supports the View Transitions API. */
	get supported(): boolean;
	/**
	* Run `update` inside a view transition. Resolves once the DOM
	* callback has committed AND the animation has finished. On
	* unsupported engines, just runs `update()` directly.
	*
	* `afterUpdate` is invoked **inside** the startViewTransition
	* callback, after `update()` resolves but before the callback
	* returns. This is critical: the browser captures the new-state
	* snapshot the moment the callback returns, so any shared
	* `view-transition-name` on the origin element has to be cleared
	* before that snapshot or the UA sees two elements sharing the
	* same name and aborts the morph. #ref: regression from the
	* pre-refactor implementation which cleared during
	* updateCallbackDone (too late).
	*/
	run(update: () => void | Promise<void>, afterUpdate?: () => void): Promise<void>;
}