import { Observable } from 'rxjs';
import { ContentDensityMode } from '../types/content-density.mode';
/**
 * Abstract provider class for providing content density storage functionality
 * Default implementation is MemoryContentDensityStorage
 */
export declare abstract class ContentDensityStorage {
    /**
     * Get listener for current density updates
     */
    abstract getContentDensity(): Observable<ContentDensityMode>;
    /**
     * Save updated configuration
     * @param density
     */
    abstract setContentDensity(density: ContentDensityMode): Observable<void>;
}
