constructor(graphics) {
    super(componentNames.CROPPER, graphics);

    /**
     * Cropzone
     * @type {Cropzone}
     * @private
     */
    this._cropzone = null;

    /**
     * StartX of Cropzone
     * @type {number}
     * @private
     */
    this._startX = null;

    /**
     * StartY of Cropzone
     * @type {number}
     * @private
     */
    this._startY = null;

    /**
     * State whether shortcut key is pressed or not
     * @type {boolean}
     * @private
     */
    this._withShiftKey = false;

    /**
     * Listeners
     * @type {object.<string, function>}
     * @private
     */
    this._listeners = {
      keydown: this._onKeyDown.bind(this),
      keyup: this._onKeyUp.bind(this),
      mousedown: this._onFabricMouseDown.bind(this),
      mousemove: this._onFabricMouseMove.bind(this),
      mouseup: this._onFabricMouseUp.bind(this),
    };
  }
Cropper components
@param {Graphics} graphics - Graphics instance
@extends {Component}
@class Cropper
@ignore