/**
 * Thumbnail side panel controller.
 *
 * Manages the collapsible left panel that displays page thumbnails.
 * Each thumbnail is a small canvas rendering of a PDF page. Clicking a
 * thumbnail navigates the main viewer to the corresponding page.
 */
export default class ThumbnailPanel {
    /** Button that toggles the panel open/closed. */
    private readonly thumbnailPanelToggle;
    /** The left panel container element. */
    private readonly thumbnailPanel;
    /** The main page container element (layout adjusts when the panel opens/closes). */
    private readonly pagegContainer;
    /** The scrollable container that holds all thumbnail nodes. */
    private readonly thumbnailsPanel;
    /** All rendered thumbnail DOM nodes in page order. */
    private readonly thumbnailNodes;
    /** The currently active (highlighted) thumbnail node. */
    private activeThumbnailNode;
    /** Callback invoked when a thumbnail is clicked. */
    private selectListener;
    /**
     * Initializes the thumbnail panel by rendering thumbnails for all pages
     * and setting up toggle and click event listeners.
     *
     * @param context - The root element containing the panel-related elements.
     * @param pages   - Array of pdf.js page proxy objects to render as thumbnails.
     */
    constructor(context: HTMLElement, pages: any[]);
    /**
     * Opens the thumbnail panel and adjusts the page container layout.
     */
    open(): void;
    /**
     * Closes the thumbnail panel and adjusts the page container layout.
     */
    close(): void;
    /**
     * Highlights the thumbnail for the specified page and scrolls it into view if necessary.
     *
     * @param pageNum - The 1-based page number to activate.
     */
    activatePage(pageNum: number): void;
    /**
     * Renders a canvas thumbnail for each PDF page and appends them to the thumbnail panel.
     *
     * @param pages - Array of pdf.js page proxy objects.
     * @returns Array of the created thumbnail container DOM nodes.
     */
    private renderThumbnails;
    /**
     * Registers a callback that is invoked when a thumbnail is clicked.
     *
     * @param listener - Callback receiving the 1-based page number of the selected thumbnail.
     * @returns This instance for chaining.
     */
    onSelect(listener: (pageNum: number) => void): ThumbnailPanel;
}