/// <reference types="node" />
import { EventEmitter } from 'events';
import ViewState from '../ViewState';
import Viewer from '../viewer/Viewer';
import { Vector2D } from '../../common/geometry';
export declare type ViewStateResizeTransformer = (viewState: ViewState, beforeSize: Vector2D, afterSize: Vector2D) => ViewState;
/**
 * ImageSource is an abstract class which represents a
 * 2D or 3D image from any source and draws it onto a given canvas.
 */
export default abstract class ImageSource extends EventEmitter {
    /**
     * Draws an image according to the current view state.
     * @return A promise which resolves with ImageData (of canvas).
     */
    abstract draw(viewer: Viewer, viewState: ViewState): Promise<ImageData>;
    /**
     * Returns a Promise instance which resolves when
     * preparation task is finished and draw() can be called.
     */
    ready(): Promise<void>;
    /**
     * Creates the default view state object which will be used
     * when the image is firstly loaded to a viewer.
     */
    abstract initialState(viewer: Viewer): ViewState;
    getResizeTransformer(): ViewStateResizeTransformer;
}