import GcPdfViewer from "..";
export declare class ExternalPdfManager {
    viewer: GcPdfViewer;
    static readonly EMPTY_FILE_ID = "blank";
    _loadedDocs: {
        [id: string]: any;
    };
    _loadedDocsPromises: {
        [id: string]: any;
    };
    constructor(viewer: GcPdfViewer);
    getDocument(fileId1: string, array?: Uint8Array): Promise<any>;
    cleanup(): void;
    renderThumbImage(fileId: string, pageIndex: number, rotateAngle?: number): Promise<{
        img: HTMLImageElement;
        sizeRatio: number;
    }>;
    /**
     * Creates and prepares a 2D rendering context for generating page thumbnails.
     * The method ensures correct scaling for HiDPI displays and applies
     * a white background to avoid transparency artifacts.
     */
    private _getPageDrawContext;
    /**
     * Renders a PDF page into a thumbnail image element.
     * Handles rotation, HiDPI scaling, and ensures a white background.
     *
     * @param page - PDF.js page object
     * @param rotateAngle - Optional additional rotation angle in degrees
     * @returns A promise that resolves to an object containing:
     *          - img: The generated thumbnail as an HTMLImageElement
     *          - sizeRatio: The page aspect ratio (height / width)
     */
    renderPageThumbnail(page: any, rotateAngle?: number): Promise<{
        img: HTMLImageElement;
        sizeRatio: number;
    }>;
}