/**
 * Helper class to determine the vertical layout of a collection of gutter content elements, such that they are aligned
 * vertically with their anchor elements, but don't overlap each other.
 */
export declare class GutterLayout {
    protected root: HTMLElement;
    protected buffer: number;
    protected tops: WeakMap<HTMLElement, number>;
    protected anchors: WeakMap<HTMLElement, HTMLElement>;
    /**
     * @param root root element for determining heights against. This MUST have a position style attribute,
     *             such as position: relative;
     */
    constructor(root: HTMLElement);
    layout(items: HTMLLaGutterItemElement[]): void;
    sortItems(items: HTMLLaGutterItemElement[]): HTMLLaGutterItemElement[];
    /**
     * Comparator that sorts items be ascending top value.
     */
    compareItems(a: HTMLLaGutterItemElement, b: HTMLLaGutterItemElement): number;
    layoutUpwards(items: HTMLLaGutterItemElement[], start: number, watermark: number): void;
    layoutDownwards(items: HTMLLaGutterItemElement[], start: number, watermark: number): void;
    updateAnchorsAndItems(items: HTMLLaGutterItemElement[]): void;
    getItemAnchor(item: HTMLLaGutterItemElement): HTMLElement | null;
    updateTops(items: HTMLLaGutterItemElement[]): void;
    /**
     * Find the top of an element, relative to this.root.
     * @param element
     * @returns {number}
     */
    calculateTop(element: HTMLElement): number;
}