import { ToolSerial, WidgetBase, ToolInstanceSerial } from './Widgets';
export interface RulerSerial extends ToolInstanceSerial {
    calibrationFactor: number;
    distance: number;
    units: string;
}
export declare class WidgetRuler extends WidgetBase {
    private _serials;
    calibrationFactor: number;
    worldPosition: any;
    protected _updateDOM(): void;
    protected _update(): void;
    protected _updateMeshPosition(): void;
    protected _updateDOMColor(): void;
    protected _createUniqueBindings(): void;
    protected _createUniqueListeners(): void;
    protected _createDOM(): void;
    protected _createMesh(): void;
    protected _hideDOM(): void;
    protected _showDOM(): void;
    onHover(evt: any): void;
    onStart(evt: any): void;
    onMove(evt: any): void;
    onEnd(): void;
    getMeasurements(): {
        distance: number;
        units: string;
    };
    protected _initialize(baseSerial: ToolSerial, extendedSerial?: ToolInstanceSerial): void;
    protected _removeEventListeners(): void;
    free(): void;
}