export declare type ViewportUpdatedCallback = (viewableArea: string[], diff: string[], finished: boolean) => void;
export declare class DisplayBuffer {
    get width(): number;
    get position(): number;
    private _buffer;
    private _position;
    private _viewportUpdatedCallback;
    constructor(contents?: string[]);
    clear(): void;
    push(content: string[]): void;
    scrollViewport(distance?: number): void;
    onViewportUpdated(callback: ViewportUpdatedCallback): void;
    autoScroll(speedMs?: number): Promise<void>;
    get visibleArea(): string[];
}