import { DocumentRenderer } from '../../../spineItem/renderer/DocumentRenderer';
import { Observable } from 'rxjs';
export declare class HtmlRenderer extends DocumentRenderer {
    onCreateDocument(): Observable<HTMLIFrameElement>;
    onLoadDocument(): Observable<HTMLIFrameElement>;
    onUnload(): void;
    onLayout({ minPageSpread, blankPagePosition, spreadPosition, }: {
        minPageSpread: number;
        blankPagePosition: `before` | `after` | `none`;
        spreadPosition: `none` | `left` | `right`;
    }): Observable<{
        width: number;
        height: number;
    } | undefined>;
    onRenderHeadless(): Observable<Document | undefined>;
    private isPrePaginated;
    private isImageType;
    private getFrameElement;
    private prepareFrameForAttach;
    private revealFrameAfterReady;
    getComputedStyleAfterLoad(): CSSStyleDeclaration | undefined;
    get writingMode(): "vertical-rl" | "horizontal-tb" | undefined;
    get readingDirection(): "ltr" | "rtl" | undefined;
    getDocumentFrame(): HTMLIFrameElement | undefined;
}