/**
 * Reactive viewer chrome state (runes-based): current slide, zoom mode, and
 * fullscreen flag. The Svelte analogue of the Vue binding's `useViewerState`
 * essentials, kept out of the SFC so it is unit-testable without a DOM.
 */
export declare class ViewerState {
    #private;
    /** Number of slides in the loaded presentation. */
    slideCount: number;
    /** Active slide index (0-based). */
    current: number;
    /** True while the viewer root is the fullscreen element. */
    isFullscreen: boolean;
    /** Manual zoom percent, or `null` for fit-to-viewport. */
    get zoomPercent(): number | null;
    set zoomPercent(percent: number | null);
    /** Reset for a freshly-loaded presentation. */
    reset(slideCount: number, initialSlide?: number): void;
    goTo(index: number): void;
    next(): void;
    prev(): void;
    first(): void;
    last(): void;
    /**
     * Zoom one step in/out from the currently-effective percent. While in fit
     * mode the state does not know the fitted percent (it depends on viewport
     * measurements), so the component passes it in.
     */
    zoomIn(effectivePercent: number): void;
    zoomOut(effectivePercent: number): void;
    zoomToFit(): void;
    /**
     * Apply a keyboard navigation key. Returns true when the key was handled
     * (so the caller can `preventDefault()`).
     */
    handleNavigationKey(key: string): boolean;
}
//# sourceMappingURL=viewer-state.svelte.d.ts.map