/**
 * Owns keyboard focus entry, containment, and restoration for one dialog.
 */
export declare class DialogFocusScope {
    private readonly dialogElement;
    private readonly fallbackElement;
    private focusableElementsCache;
    private focusMutationObserver;
    private restoreTarget;
    private isActive;
    private ownsTemporaryFallbackTabIndex;
    /**
     * @param dialogElement - Native dialog whose focus is scoped.
     * @param fallbackElement - Host element used when the original trigger disappears.
     */
    constructor(dialogElement: HTMLDialogElement, fallbackElement: HTMLElement);
    /**
     * Captures the external trigger before `showModal()` moves focus.
     */
    captureRestoreTarget(): void;
    /**
     * Installs the Tab scope and focuses dialog content after the dialog opens.
     *
     * @param contentElement - Newly rendered form or confirmation content.
     */
    activate(contentElement: HTMLElement): void;
    /**
     * Focuses the first invalid control or the first interactive content.
     *
     * @param contentElement - Current form or confirmation content.
     */
    focusInitial(contentElement: HTMLElement): void;
    /**
     * Removes focus containment and optionally restores the opening trigger.
     *
     * @param shouldRestore - Whether focus should return outside the dialog.
     */
    deactivate(shouldRestore: boolean): void;
    /**
     * Removes the scope without retaining a trigger reference.
     */
    destroy(): void;
    private focusFallback;
    private readonly restoreFallbackFocusability;
    private readonly handleKeyDown;
    private readonly handleFocusMutations;
    private affectsFocusableElements;
    private applyPendingFocusMutations;
    private getFocusableElements;
}