前端的裁剪我知道的可以分为这么两种：flash一种，canvas一种。现在用的多的是canvas这种。

其实裁剪最本质的原理：通过工具获取到图片（不是JS那种获取DOM的方式，比如flash获取到图片，对图片任意操作，canvas也是一样，将图片放在画布上，任意操作）

本文使用的是canvas这种方式，借助的是cropper.js实现图片的裁剪。

由于前端页面使用的是layui这个框架，所有使用cropper时，最好的能够将cropper这个包作为一个layui的扩展嵌入到layui中，这样都省事，嵌入很简单，具体可以参考下面我封装好的代码

备注：cropper默认裁剪后的图片格式为png格式，如果需要自定义上传图片的格式，可以参考下面这段代码，如果不需要请直接忽略

cropper修改上传图片的格式：

var cas=imageEle.cropper('getCroppedCanvas');
var baseurl=cas.toDataURL('image/jpeg');
console.log(baseurl); //生成base图片的格式

// 展示裁剪的图片的两种方式
// 方式一
$('.cavans').html(cas) //在body显示出canvas元素

// 方式二
$('.canvans').attr("src", baseurl);

封装好的cropper源码如下，包括cropper-jQuery的

具体代码：

cropper-css

/*!
 * Cropper.js v1.4.3
 * https://fengyuanchen.github.io/cropperjs
 *
 * Copyright 2015-present Chen Fengyuan
 * Released under the MIT license
 *
 * Date: 2018-10-24T13:07:11.429Z
 */

.cropper-container {
 direction: ltr;
 font-size: 0;
 line-height: 0;
 position: relative;
 -ms-touch-action: none;
 touch-action: none;
 -webkit-user-select: none;
 -moz-user-select: none;
 -ms-user-select: none;
 user-select: none;
}

.cropper-container img {
 display: block;
 height: 100%;
 image-orientation: 0deg;
 max-height: none !important;
 max-width: none !important;
 min-height: 0 !important;
 min-width: 0 !important;
 width: 100%;
}

.cropper-wrap-box,
.cropper-canvas,
.cropper-drag-box,
.cropper-crop-box,
.cropper-modal {
 bottom: 0;
 left: 0;
 position: absolute;
 right: 0;
 top: 0;
}

.cropper-wrap-box,
.cropper-canvas {
 overflow: hidden;
}

.cropper-drag-box {
 background-color: #fff;
 opacity: 0;
}

.cropper-modal {
 background-color: #000;
 opacity: .5;
}

.cropper-view-box {
 display: block;
 height: 100%;
 outline-color: rgba(51, 153, 255, 0.75);
 outline: 1px solid #39f;
 overflow: hidden;
 width: 100%;
}

.cropper-dashed {
 border: 0 dashed #eee;
 display: block;
 opacity: .5;
 position: absolute;
}

.cropper-dashed.dashed-h {
 border-bottom-width: 1px;
 border-top-width: 1px;
 height: calc(100% / 3);
 left: 0;
 top: calc(100% / 3);
 width: 100%;
}

.cropper-dashed.dashed-v {
 border-left-width: 1px;
 border-right-width: 1px;
 height: 100%;
 left: calc(100% / 3);
 top: 0;
 width: calc(100% / 3);
}

.cropper-center {
 display: block;
 height: 0;
 left: 50%;
 opacity: .75;
 position: absolute;
 top: 50%;
 width: 0;
}

.cropper-center:before,
.cropper-center:after {
 background-color: #eee;
 content: ' ';
 display: block;
 position: absolute;
}

.cropper-center:before {
 height: 1px;
 left: -3px;
 top: 0;
 width: 7px;
}

.cropper-center:after {
 height: 7px;
 left: 0;
 top: -3px;
 width: 1px;
}

.cropper-face,
.cropper-line,
.cropper-point {
 display: block;
 height: 100%;
 opacity: .1;
 position: absolute;
 width: 100%;
}

.cropper-face {
 background-color: #fff;
 left: 0;
 top: 0;
}

.cropper-line {
 background-color: #39f;
}

.cropper-line.line-e {
 cursor: ew-resize;
 right: -3px;
 top: 0;
 width: 5px;
}

.cropper-line.line-n {
 cursor: ns-resize;
 height: 5px;
 left: 0;
 top: -3px;
}

.cropper-line.line-w {
 cursor: ew-resize;
 left: -3px;
 top: 0;
 width: 5px;
}

.cropper-line.line-s {
 bottom: -3px;
 cursor: ns-resize;
 height: 5px;
 left: 0;
}

.cropper-point {
 background-color: #39f;
 height: 5px;
 opacity: .75;
 width: 5px;
}

.cropper-point.point-e {
 cursor: ew-resize;
 margin-top: -3px;
 right: -3px;
 top: 50%;
}

.cropper-point.point-n {
 cursor: ns-resize;
 left: 50%;
 margin-left: -3px;
 top: -3px;
}

.cropper-point.point-w {
 cursor: ew-resize;
 left: -3px;
 margin-top: -3px;
 top: 50%;
}

.cropper-point.point-s {
 bottom: -3px;
 cursor: s-resize;
 left: 50%;
 margin-left: -3px;
}

.cropper-point.point-ne {
 cursor: nesw-resize;
 right: -3px;
 top: -3px;
}

.cropper-point.point-nw {
 cursor: nwse-resize;
 left: -3px;
 top: -3px;
}

.cropper-point.point-sw {
 bottom: -3px;
 cursor: nesw-resize;
 left: -3px;
}

.cropper-point.point-se {
 bottom: -3px;
 cursor: nwse-resize;
 height: 20px;
 opacity: 1;
 right: -3px;
 width: 20px;
}

@media (min-width: 768px) {
 .cropper-point.point-se {
 height: 15px;
 width: 15px;
 }
}

@media (min-width: 992px) {
 .cropper-point.point-se {
 height: 10px;
 width: 10px;
 }
}

@media (min-width: 1200px) {
 .cropper-point.point-se {
 height: 5px;
 opacity: .75;
 width: 5px;
 }
}

.cropper-point.point-se:before {
 background-color: #39f;
 bottom: -50%;
 content: ' ';
 display: block;
 height: 200%;
 opacity: 0;
 position: absolute;
 right: -50%;
 width: 200%;
}

.cropper-invisible {
 opacity: 0;
}

.cropper-bg {
 background-image: url('data:image/png;base,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAAA3NCSVQICAjb4U/gAAAABlBMVEXMzMz////TjRV2AAAACXBIWXMAAArrAAAK6wGCiw1aAAAAHHRFWHRTb2Z0d2FyZQBBZG9iZSBGaXJld29ya3MgQ1M26LyyjAAAABFJREFUCJlj+M/AgBVhF/0PAH6/D/HkDxOGAAAAAElFTkSuQmCC');
}

.cropper-hide {
 display: block;
 height: 0;
 position: absolute;
 width: 0;
}

.cropper-hidden {
 display: none !important;
}

.cropper-move {
 cursor: move;
}

.cropper-crop {
 cursor: crosshair;
}

.cropper-disabled .cropper-drag-box,
.cropper-disabled .cropper-face,
.cropper-disabled .cropper-line,
.cropper-disabled .cropper-point {
 cursor: not-allowed;
}

cropper-css

cropper-js

/*!
 * Cropper.js v1.4.3
 * https://fengyuanchen.github.io/cropperjs
 *
 * Copyright 2015-present Chen Fengyuan
 * Released under the MIT license
 *
 * Date: 2018-10-24T13:07:15.032Z
 */

(function (global, factory) {
 typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
 typeof define === 'function' && define.amd ? define(factory) :
 global.layui && layui.define ? layui.define(function (exports) {
 exports('cropper', factory())
 }) :
 (global.Cropper = factory());
}(this, (function () {
 'use strict';

 function _typeof(obj) {
 if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
 _typeof = function (obj) {
 return typeof obj;
 };
 } else {
 _typeof = function (obj) {
 return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
 };
 }

 return _typeof(obj);
 }

 function _classCallCheck(instance, Constructor) {
 if (!(instance instanceof Constructor)) {
 throw new TypeError("Cannot call a class as a function");
 }
 }

 function _defineProperties(target, props) {
 for (var i = 0; i < props.length; i++) {
 var descriptor = props[i];
 descriptor.enumerable = descriptor.enumerable || false;
 descriptor.configurable = true;
 if ("value" in descriptor) descriptor.writable = true;
 Object.defineProperty(target, descriptor.key, descriptor);
 }
 }

 function _createClass(Constructor, protoProps, staticProps) {
 if (protoProps) _defineProperties(Constructor.prototype, protoProps);
 if (staticProps) _defineProperties(Constructor, staticProps);
 return Constructor;
 }

 function _toConsumableArray(arr) {
 return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _nonIterableSpread();
 }

 function _arrayWithoutHoles(arr) {
 if (Array.isArray(arr)) {
 for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) arr2[i] = arr[i];

 return arr2;
 }
 }

 function _iterableToArray(iter) {
 if (Symbol.iterator in Object(iter) || Object.prototype.toString.call(iter) === "[object Arguments]") return Array.from(iter);
 }

 function _nonIterableSpread() {
 throw new TypeError("Invalid attempt to spread non-iterable instance");
 }

 var IN_BROWSER = typeof window !== 'undefined';
 var WINDOW = IN_BROWSER ? window : {};
 var NAMESPACE = 'cropper'; // Actions

 var ACTION_ALL = 'all';
 var ACTION_CROP = 'crop';
 var ACTION_MOVE = 'move';
 var ACTION_ZOOM = 'zoom';
 var ACTION_EAST = 'e';
 var ACTION_WEST = 'w';
 var ACTION_SOUTH = 's';
 var ACTION_NORTH = 'n';
 var ACTION_NORTH_EAST = 'ne';
 var ACTION_NORTH_WEST = 'nw';
 var ACTION_SOUTH_EAST = 'se';
 var ACTION_SOUTH_WEST = 'sw'; // Classes

 var CLASS_CROP = "".concat(NAMESPACE, "-crop");
 var CLASS_DISABLED = "".concat(NAMESPACE, "-disabled");
 var CLASS_HIDDEN = "".concat(NAMESPACE, "-hidden");
 var CLASS_HIDE = "".concat(NAMESPACE, "-hide");
 var CLASS_INVISIBLE = "".concat(NAMESPACE, "-invisible");
 var CLASS_MODAL = "".concat(NAMESPACE, "-modal");
 var CLASS_MOVE = "".concat(NAMESPACE, "-move"); // Data keys

 var DATA_ACTION = "".concat(NAMESPACE, "Action");
 var DATA_PREVIEW = "".concat(NAMESPACE, "Preview"); // Drag modes

 var DRAG_MODE_CROP = 'crop';
 var DRAG_MODE_MOVE = 'move';
 var DRAG_MODE_NONE = 'none'; // Events

 var EVENT_CROP = 'crop';
 var EVENT_CROP_END = 'cropend';
 var EVENT_CROP_MOVE = 'cropmove';
 var EVENT_CROP_START = 'cropstart';
 var EVENT_DBLCLICK = 'dblclick';
 var EVENT_POINTER_DOWN = WINDOW.PointerEvent ? 'pointerdown' : 'touchstart mousedown';
 var EVENT_POINTER_MOVE = WINDOW.PointerEvent ? 'pointermove' : 'touchmove mousemove';
 var EVENT_POINTER_UP = WINDOW.PointerEvent ? 'pointerup pointercancel' : 'touchend touchcancel mouseup';
 var EVENT_READY = 'ready';
 var EVENT_RESIZE = 'resize';
 var EVENT_WHEEL = 'wheel mousewheel DOMMouseScroll';
 var EVENT_ZOOM = 'zoom'; // Mime types

 var MIME_TYPE_JPEG = 'image/jpeg'; // RegExps

 var REGEXP_ACTIONS = /^(?:e|w|s|n|se|sw|ne|nw|all|crop|move|zoom)$/;
 var REGEXP_DATA_URL = /^data:/;
 var REGEXP_DATA_URL_JPEG = /^data:image/jpeg;base,/;
 var REGEXP_TAG_NAME = /^(?:img|canvas)$/i;

 var DEFAULTS = {
 // Define the view mode of the cropper
 viewMode: 0,
 // 0, 1, 2, 3
 // Define the dragging mode of the cropper
 dragMode: DRAG_MODE_CROP,
 // 'crop', 'move' or 'none'
 // Define the initial aspect ratio of the crop box
 initialAspectRatio: NaN,
 // Define the aspect ratio of the crop box
 aspectRatio: NaN,
 // An object with the previous cropping result data
 data: null,
 // A selector for adding extra containers to preview
 preview: '',
 // Re-render the cropper when resize the window
 responsive: true,
 // Restore the cropped area after resize the window
 restore: true,
 // Check if the current image is a cross-origin image
 checkCrossOrigin: false,
 // Check the current image's Exif Orientation information
 checkOrientation: true,
 // Show the black modal
 modal: true,
 // Show the dashed lines for guiding
 guides: true,
 // Show the center indicator for guiding
 center: true,
 // Show the white modal to highlight the crop box
 highlight: true,
 // Show the grid background
 background: true,
 // Enable to crop the image automatically when initialize
 autoCrop: true,
 // Define the percentage of automatic cropping area when initializes
 autoCropArea: 0.8,
 // Enable to move the image
 movable: true,
 // Enable to rotate the image
 rotatable: true,
 // Enable to scale the image
 scalable: true,
 // Enable to zoom the image
 zoomable: true,
 // Enable to zoom the image by dragging touch
 zoomOnTouch: true,
 // Enable to zoom the image by wheeling mouse
 zoomOnWheel: true,
 // Define zoom ratio when zoom the image by wheeling mouse
 wheelZoomRatio: 0.1,
 // Enable to move the crop box
 cropBoxMovable: true,
 // Enable to resize the crop box
 cropBoxResizable: true,
 // Toggle drag mode between "crop" and "move" when click twice on the cropper
 toggleDragModeOnDblclick: true,
 // Size limitation
 minCanvasWidth: 0,
 minCanvasHeight: 0,
 minCropBoxWidth: 0,
 minCropBoxHeight: 0,
 minContainerWidth: 200,
 minContainerHeight: 100,
 // Shortcuts of events
 ready: null,
 cropstart: null,
 cropmove: null,
 cropend: null,
 crop: null,
 zoom: null
 };

 var TEMPLATE = '<div class="cropper-container" touch-action="none">' + '<div class="cropper-wrap-box">' + '<div class="cropper-canvas"></div>' + '</div>' + '<div class="cropper-drag-box"></div>' + '<div class="cropper-crop-box">' + '<span class="cropper-view-box"></span>' + '<span class="cropper-dashed dashed-h"></span>' + '<span class="cropper-dashed dashed-v"></span>' + '<span class="cropper-center"></span>' + '<span class="cropper-face"></span>' + '<span class="cropper-line line-e" data-cropper-action="e"></span>' + '<span class="cropper-line line-n" data-cropper-action="n"></span>' + '<span class="cropper-line line-w" data-cropper-action="w"></span>' + '<span class="cropper-line line-s" data-cropper-action="s"></span>' + '<span class="cropper-point point-e" data-cropper-action="e"></span>' + '<span class="cropper-point point-n" data-cropper-action="n"></span>' + '<span class="cropper-point point-w" data-cropper-action="w"></span>' + '<span class="cropper-point point-s" data-cropper-action="s"></span>' + '<span class="cropper-point point-ne" data-cropper-action="ne"></span>' + '<span class="cropper-point point-nw" data-cropper-action="nw"></span>' + '<span class="cropper-point point-sw" data-cropper-action="sw"></span>' + '<span class="cropper-point point-se" data-cropper-action="se"></span>' + '</div>' + '</div>';

 /**
 * Check if the given value is not a number.
 */

 var isNaN = Number.isNaN || WINDOW.isNaN;

 /**
 * Check if the given value is a number.
 * @param {*} value - The value to check.
 * @returns {boolean} Returns `true` if the given value is a number, else `false`.
 */

 function isNumber(value) {
 return typeof value === 'number' && !isNaN(value);
 }

 /**
 * Check if the given value is undefined.
 * @param {*} value - The value to check.
 * @returns {boolean} Returns `true` if the given value is undefined, else `false`.
 */

 function isUndefined(value) {
 return typeof value === 'undefined';
 }

 /**
 * Check if the given value is an object.
 * @param {*} value - The value to check.
 * @returns {boolean} Returns `true` if the given value is an object, else `false`.
 */

 function isObject(value) {
 return _typeof(value) === 'object' && value !== null;
 }

 var hasOwnProperty = Object.prototype.hasOwnProperty;

 /**
 * Check if the given value is a plain object.
 * @param {*} value - The value to check.
 * @returns {boolean} Returns `true` if the given value is a plain object, else `false`.
 */

 function isPlainObject(value) {
 if (!isObject(value)) {
 return false;
 }

 try {
 var _constructor = value.constructor;
 var prototype = _constructor.prototype;
 return _constructor && prototype && hasOwnProperty.call(prototype, 'isPrototypeOf');
 } catch (e) {
 return false;
 }
 }

 /**
 * Check if the given value is a function.
 * @param {*} value - The value to check.
 * @returns {boolean} Returns `true` if the given value is a function, else `false`.
 */

 function isFunction(value) {
 return typeof value === 'function';
 }

 /**
 * Iterate the given data.
 * @param {*} data - The data to iterate.
 * @param {Function} callback - The process function for each element.
 * @returns {*} The original data.
 */

 function forEach(data, callback) {
 if (data && isFunction(callback)) {
 if (Array.isArray(data) || isNumber(data.length)
 /* array-like */
 ) {
 var length = data.length;
 var i;

 for (i = 0; i < length; i += 1) {
 if (callback.call(data, data[i], i, data) === false) {
 break;
 }
 }
 } else if (isObject(data)) {
 Object.keys(data).forEach(function (key) {
 callback.call(data, data[key], key, data);
 });
 }
 }

 return data;
 }

 /**
 * Extend the given object.
 * @param {*} obj - The object to be extended.
 * @param {*} args - The rest objects which will be merged to the first object.
 * @returns {Object} The extended object.
 */

 var assign = Object.assign || function assign(obj) {
 for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
 args[_key - 1] = arguments[_key];
 }

 if (isObject(obj) && args.length > 0) {
 args.forEach(function (arg) {
 if (isObject(arg)) {
 Object.keys(arg).forEach(function (key) {
 obj[key] = arg[key];
 });
 }
 });
 }

 return obj;
 };
 var REGEXP_DECIMALS = /.d*(?:0|9){12}d*$/;

 /**
 * Normalize decimal number.
 * Check out {@link http://0.30000000000000004.com/}
 * @param {number} value - The value to normalize.
 * @param {number} [times=100000000000] - The times for normalizing.
 * @returns {number} Returns the normalized number.
 */

 function normalizeDecimalNumber(value) {
 var times = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 100000000000;
 return REGEXP_DECIMALS.test(value) ? Math.round(value * times) / times : value;
 }

 var REGEXP_SUFFIX = /^(?:width|height|left|top|marginLeft|marginTop)$/;

 /**
 * Apply styles to the given element.
 * @param {Element} element - The target element.
 * @param {Object} styles - The styles for applying.
 */

 function setStyle(element, styles) {
 var style = element.style;
 forEach(styles, function (value, property) {
 if (REGEXP_SUFFIX.test(property) && isNumber(value)) {
 value += 'px';
 }

 style[property] = value;
 });
 }

 /**
 * Check if the given element has a special class.
 * @param {Element} element - The element to check.
 * @param {string} value - The class to search.
 * @returns {boolean} Returns `true` if the special class was found.
 */

 function hasClass(element, value) {
 return element.classList ? element.classList.contains(value) : element.className.indexOf(value) > -1;
 }

 /**
 * Add classes to the given element.
 * @param {Element} element - The target element.
 * @param {string} value - The classes to be added.
 */

 function addClass(element, value) {
 if (!value) {
 return;
 }

 if (isNumber(element.length)) {
 forEach(element, function (elem) {
 addClass(elem, value);
 });
 return;
 }

 if (element.classList) {
 element.classList.add(value);
 return;
 }

 var className = element.className.trim();

 if (!className) {
 element.className = value;
 } else if (className.indexOf(value) < 0) {
 element.className = "".concat(className, " ").concat(value);
 }
 }

 /**
 * Remove classes from the given element.
 * @param {Element} element - The target element.
 * @param {string} value - The classes to be removed.
 */

 function removeClass(element, value) {
 if (!value) {
 return;
 }

 if (isNumber(element.length)) {
 forEach(element, function (elem) {
 removeClass(elem, value);
 });
 return;
 }

 if (element.classList) {
 element.classList.remove(value);
 return;
 }

 if (element.className.indexOf(value) >= 0) {
 element.className = element.className.replace(value, '');
 }
 }

 /**
 * Add or remove classes from the given element.
 * @param {Element} element - The target element.
 * @param {string} value - The classes to be toggled.
 * @param {boolean} added - Add only.
 */

 function toggleClass(element, value, added) {
 if (!value) {
 return;
 }

 if (isNumber(element.length)) {
 forEach(element, function (elem) {
 toggleClass(elem, value, added);
 });
 return;
 } // IE10-11 doesn't support the second parameter of `classList.toggle`


 if (added) {
 addClass(element, value);
 } else {
 removeClass(element, value);
 }
 }

 var REGEXP_HYPHENATE = /([a-zd])([A-Z])/g;

 /**
 * Transform the given string from camelCase to kebab-case
 * @param {string} value - The value to transform.
 * @returns {string} The transformed value.
 */

 function hyphenate(value) {
 return value.replace(REGEXP_HYPHENATE, '$1-$2').toLowerCase();
 }

 /**
 * Get data from the given element.
 * @param {Element} element - The target element.
 * @param {string} name - The data key to get.
 * @returns {string} The data value.
 */

 function getData(element, name) {
 if (isObject(element[name])) {
 return element[name];
 }

 if (element.dataset) {
 return element.dataset[name];
 }

 return element.getAttribute("data-".concat(hyphenate(name)));
 }

 /**
 * Set data to the given element.
 * @param {Element} element - The target element.
 * @param {string} name - The data key to set.
 * @param {string} data - The data value.
 */

 function setData(element, name, data) {
 if (isObject(data)) {
 element[name] = data;
 } else if (element.dataset) {
 element.dataset[name] = data;
 } else {
 element.setAttribute("data-".concat(hyphenate(name)), data);
 }
 }

 /**
 * Remove data from the given element.
 * @param {Element} element - The target element.
 * @param {string} name - The data key to remove.
 */

 function removeData(element, name) {
 if (isObject(element[name])) {
 try {
 delete element[name];
 } catch (e) {
 element[name] = undefined;
 }
 } else if (element.dataset) {
 // #128 Safari not allows to delete dataset property
 try {
 delete element.dataset[name];
 } catch (e) {
 element.dataset[name] = undefined;
 }
 } else {
 element.removeAttribute("data-".concat(hyphenate(name)));
 }
 }

 var REGEXP_SPACES = /ss*/;

 var onceSupported = function () {
 var supported = false;

 if (IN_BROWSER) {
 var once = false;

 var listener = function listener() {
 };

 var options = Object.defineProperty({}, 'once', {
 get: function get() {
 supported = true;
 return once;
 },

 /**
 * This setter can fix a `TypeError` in strict mode
 * {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Getter_only}
 * @param {boolean} value - The value to set
 */
 set: function set(value) {
 once = value;
 }
 });
 WINDOW.addEventListener('test', listener, options);
 WINDOW.removeEventListener('test', listener, options);
 }

 return supported;
 }();

 /**
 * Remove event listener from the target element.
 * @param {Element} element - The event target.
 * @param {string} type - The event type(s).
 * @param {Function} listener - The event listener.
 * @param {Object} options - The event options.
 */


 function removeListener(element, type, listener) {
 var options = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : {};
 var handler = listener;
 type.trim().split(REGEXP_SPACES).forEach(function (event) {
 if (!onceSupported) {
 var listeners = element.listeners;

 if (listeners && listeners[event] && listeners[event][listener]) {
 handler = listeners[event][listener];
 delete listeners[event][listener];

 if (Object.keys(listeners[event]).length === 0) {
 delete listeners[event];
 }

 if (Object.keys(listeners).length === 0) {
 delete element.listeners;
 }
 }
 }

 element.removeEventListener(event, handler, options);
 });
 }

 /**
 * Add event listener to the target element.
 * @param {Element} element - The event target.
 * @param {string} type - The event type(s).
 * @param {Function} listener - The event listener.
 * @param {Object} options - The event options.
 */

 function addListener(element, type, listener) {
 var options = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : {};
 var _handler = listener;
 type.trim().split(REGEXP_SPACES).forEach(function (event) {
 if (options.once && !onceSupported) {
 var _element$listeners = element.listeners,
 listeners = _element$listeners === void 0 ? {} : _element$listeners;

 _handler = function handler() {
 delete listeners[event][listener];
 element.removeEventListener(event, _handler, options);

 for (var _len2 = arguments.length, args = new Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
 args[_key2] = arguments[_key2];
 }

 listener.apply(element, args);
 };

 if (!listeners[event]) {
 listeners[event] = {};
 }

 if (listeners[event][listener]) {
 element.removeEventListener(event, listeners[event][listener], options);
 }

 listeners[event][listener] = _handler;
 element.listeners = listeners;
 }

 element.addEventListener(event, _handler, options);
 });
 }

 /**
 * Dispatch event on the target element.
 * @param {Element} element - The event target.
 * @param {string} type - The event type(s).
 * @param {Object} data - The additional event data.
 * @returns {boolean} Indicate if the event is default prevented or not.
 */

 function dispatchEvent(element, type, data) {
 var event; // Event and CustomEvent on IE9-11 are global objects, not constructors

 if (isFunction(Event) && isFunction(CustomEvent)) {
 event = new CustomEvent(type, {
 detail: data,
 bubbles: true,
 cancelable: true
 });
 } else {
 event = document.createEvent('CustomEvent');
 event.initCustomEvent(type, true, true, data);
 }

 return element.dispatchEvent(event);
 }

 /**
 * Get the offset base on the document.
 * @param {Element} element - The target element.
 * @returns {Object} The offset data.
 */

 function getOffset(element) {
 var box = element.getBoundingClientRect();
 return {
 left: box.left + (window.pageXOffset - document.documentElement.clientLeft),
 top: box.top + (window.pageYOffset - document.documentElement.clientTop)
 };
 }

 var location = WINDOW.location;
 var REGEXP_ORIGINS = /^(https?:)//([^:/?#]+):?(d*)/i;

 /**
 * Check if the given URL is a cross origin URL.
 * @param {string} url - The target URL.
 * @returns {boolean} Returns `true` if the given URL is a cross origin URL, else `false`.
 */

 function isCrossOriginURL(url) {
 var parts = url.match(REGEXP_ORIGINS);
 return parts && (parts[1] !== location.protocol || parts[2] !== location.hostname || parts[3] !== location.port);
 }

 /**
 * Add timestamp to the given URL.
 * @param {string} url - The target URL.
 * @returns {string} The result URL.
 */

 function addTimestamp(url) {
 var timestamp = "timestamp=".concat(new Date().getTime());
 return url + (url.indexOf('?') === -1 ? '?' : '&') + timestamp;
 }

 /**
 * Get transforms base on the given object.
 * @param {Object} obj - The target object.
 * @returns {string} A string contains transform values.
 */

 function getTransforms(_ref) {
 var rotate = _ref.rotate,
 scaleX = _ref.scaleX,
 scaleY = _ref.scaleY,
 translateX = _ref.translateX,
 translateY = _ref.translateY;
 var values = [];

 if (isNumber(translateX) && translateX !== 0) {
 values.push("translateX(".concat(translateX, "px)"));
 }

 if (isNumber(translateY) && translateY !== 0) {
 values.push("translateY(".concat(translateY, "px)"));
 } // Rotate should come first before scale to match orientation transform


 if (isNumber(rotate) && rotate !== 0) {
 values.push("rotate(".concat(rotate, "deg)"));
 }

 if (isNumber(scaleX) && scaleX !== 1) {
 values.push("scaleX(".concat(scaleX, ")"));
 }

 if (isNumber(scaleY) && scaleY !== 1) {
 values.push("scaleY(".concat(scaleY, ")"));
 }

 var transform = values.length ? values.join(' ') : 'none';
 return {
 WebkitTransform: transform,
 msTransform: transform,
 transform: transform
 };
 }

 /**
 * Get the max ratio of a group of pointers.
 * @param {string} pointers - The target pointers.
 * @returns {number} The result ratio.
 */

 function getMaxZoomRatio(pointers) {
 var pointers2 = assign({}, pointers);
 var ratios = [];
 forEach(pointers, function (pointer, pointerId) {
 delete pointers2[pointerId];
 forEach(pointers2, function (pointer2) {
 var x1 = Math.abs(pointer.startX - pointer2.startX);
 var y1 = Math.abs(pointer.startY - pointer2.startY);
 var x2 = Math.abs(pointer.endX - pointer2.endX);
 var y2 = Math.abs(pointer.endY - pointer2.endY);
 var z1 = Math.sqrt(x1 * x1 + y1 * y1);
 var z2 = Math.sqrt(x2 * x2 + y2 * y2);
 var ratio = (z2 - z1) / z1;
 ratios.push(ratio);
 });
 });
 ratios.sort(function (a, b) {
 return Math.abs(a) < Math.abs(b);
 });
 return ratios[0];
 }

 /**
 * Get a pointer from an event object.
 * @param {Object} event - The target event object.
 * @param {boolean} endOnly - Indicates if only returns the end point coordinate or not.
 * @returns {Object} The result pointer contains start and/or end point coordinates.
 */

 function getPointer(_ref2, endOnly) {
 var pageX = _ref2.pageX,
 pageY = _ref2.pageY;
 var end = {
 endX: pageX,
 endY: pageY
 };
 return endOnly ? end : assign({
 startX: pageX,
 startY: pageY
 }, end);
 }

 /**
 * Get the center point coordinate of a group of pointers.
 * @param {Object} pointers - The target pointers.
 * @returns {Object} The center point coordinate.
 */

 function getPointersCenter(pointers) {
 var pageX = 0;
 var pageY = 0;
 var count = 0;
 forEach(pointers, function (_ref3) {
 var startX = _ref3.startX,
 startY = _ref3.startY;
 pageX += startX;
 pageY += startY;
 count += 1;
 });
 pageX /= count;
 pageY /= count;
 return {
 pageX: pageX,
 pageY: pageY
 };
 }

 /**
 * Check if the given value is a finite number.
 */

 var isFinite = Number.isFinite || WINDOW.isFinite;

 /**
 * Get the max sizes in a rectangle under the given aspect ratio.
 * @param {Object} data - The original sizes.
 * @param {string} [type='contain'] - The adjust type.
 * @returns {Object} The result sizes.
 */

 function getAdjustedSizes(_ref4) // or 'cover'
 {
 var aspectRatio = _ref4.aspectRatio,
 height = _ref4.height,
 width = _ref4.width;
 var type = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'contain';

 var isValidNumber = function isValidNumber(value) {
 return isFinite(value) && value > 0;
 };

 if (isValidNumber(width) && isValidNumber(height)) {
 var adjustedWidth = height * aspectRatio;

 if (type === 'contain' && adjustedWidth > width || type === 'cover' && adjustedWidth < width) {
 height = width / aspectRatio;
 } else {
 width = height * aspectRatio;
 }
 } else if (isValidNumber(width)) {
 height = width / aspectRatio;
 } else if (isValidNumber(height)) {
 width = height * aspectRatio;
 }

 return {
 width: width,
 height: height
 };
 }

 /**
 * Get the new sizes of a rectangle after rotated.
 * @param {Object} data - The original sizes.
 * @returns {Object} The result sizes.
 */

 function getRotatedSizes(_ref5) {
 var width = _ref5.width,
 height = _ref5.height,
 degree = _ref5.degree;
 degree = Math.abs(degree) % 180;

 if (degree === 90) {
 return {
 width: height,
 height: width
 };
 }

 var arc = degree % 90 * Math.PI / 180;
 var sinArc = Math.sin(arc);
 var cosArc = Math.cos(arc);
 var newWidth = width * cosArc + height * sinArc;
 var newHeight = width * sinArc + height * cosArc;
 return degree > 90 ? {
 width: newHeight,
 height: newWidth
 } : {
 width: newWidth,
 height: newHeight
 };
 }

 /**
 * Get a canvas which drew the given image.
 * @param {HTMLImageElement} image - The image for drawing.
 * @param {Object} imageData - The image data.
 * @param {Object} canvasData - The canvas data.
 * @param {Object} options - The options.
 * @returns {HTMLCanvasElement} The result canvas.
 */

 function getSourceCanvas(image, _ref6, _ref7, _ref8) {
 var imageAspectRatio = _ref6.aspectRatio,
 imageNaturalWidth = _ref6.naturalWidth,
 imageNaturalHeight = _ref6.naturalHeight,
 _ref6$rotate = _ref6.rotate,
 rotate = _ref6$rotate === void 0 ? 0 : _ref6$rotate,
 _ref6$scaleX = _ref6.scaleX,
 scaleX = _ref6$scaleX === void 0 ? 1 : _ref6$scaleX,
 _ref6$scaleY = _ref6.scaleY,
 scaleY = _ref6$scaleY === void 0 ? 1 : _ref6$scaleY;
 var aspectRatio = _ref7.aspectRatio,
 naturalWidth = _ref7.naturalWidth,
 naturalHeight = _ref7.naturalHeight;
 var _ref8$fillColor = _ref8.fillColor,
 fillColor = _ref8$fillColor === void 0 ? 'transparent' : _ref8$fillColor,
 _ref8$imageSmoothingE = _ref8.imageSmoothingEnabled,
 imageSmoothingEnabled = _ref8$imageSmoothingE === void 0 ? true : _ref8$imageSmoothingE,
 _ref8$imageSmoothingQ = _ref8.imageSmoothingQuality,
 imageSmoothingQuality = _ref8$imageSmoothingQ === void 0 ? 'low' : _ref8$imageSmoothingQ,
 _ref8$maxWidth = _ref8.maxWidth,
 maxWidth = _ref8$maxWidth === void 0 ? Infinity : _ref8$maxWidth,
 _ref8$maxHeight = _ref8.maxHeight,
 maxHeight = _ref8$maxHeight === void 0 ? Infinity : _ref8$maxHeight,
 _ref8$minWidth = _ref8.minWidth,
 minWidth = _ref8$minWidth === void 0 ? 0 : _ref8$minWidth,
 _ref8$minHeight = _ref8.minHeight,
 minHeight = _ref8$minHeight === void 0 ? 0 : _ref8$minHeight;
 var canvas = document.createElement('canvas');
 var context = canvas.getContext('2d');
 var maxSizes = getAdjustedSizes({
 aspectRatio: aspectRatio,
 width: maxWidth,
 height: maxHeight
 });
 var minSizes = getAdjustedSizes({
 aspectRatio: aspectRatio,
 width: minWidth,
 height: minHeight
 }, 'cover');
 var width = Math.min(maxSizes.width, Math.max(minSizes.width, naturalWidth));
 var height = Math.min(maxSizes.height, Math.max(minSizes.height, naturalHeight)); // Note: should always use image's natural sizes for drawing as
 // imageData.naturalWidth === canvasData.naturalHeight when rotate % 180 === 90

 var destMaxSizes = getAdjustedSizes({
 aspectRatio: imageAspectRatio,
 width: maxWidth,
 height: maxHeight
 });
 var destMinSizes = getAdjustedSizes({
 aspectRatio: imageAspectRatio,
 width: minWidth,
 height: minHeight
 }, 'cover');
 var destWidth = Math.min(destMaxSizes.width, Math.max(destMinSizes.width, imageNaturalWidth));
 var destHeight = Math.min(destMaxSizes.height, Math.max(destMinSizes.height, imageNaturalHeight));
 var params = [-destWidth / 2, -destHeight / 2, destWidth, destHeight];
 canvas.width = normalizeDecimalNumber(width);
 canvas.height = normalizeDecimalNumber(height);
 context.fillStyle = fillColor;
 context.fillRect(0, 0, width, height);
 context.save();
 context.translate(width / 2, height / 2);
 context.rotate(rotate * Math.PI / 180);
 context.scale(scaleX, scaleY);
 context.imageSmoothingEnabled = imageSmoothingEnabled;
 context.imageSmoothingQuality = imageSmoothingQuality;
 context.drawImage.apply(context, [image].concat(_toConsumableArray(params.map(function (param) {
 return Math.floor(normalizeDecimalNumber(param));
 }))));
 context.restore();
 return canvas;
 }

 var fromCharCode = String.fromCharCode;

 /**
 * Get string from char code in data view.
 * @param {DataView} dataView - The data view for read.
 * @param {number} start - The start index.
 * @param {number} length - The read length.
 * @returns {string} The read result.
 */

 function getStringFromCharCode(dataView, start, length) {
 var str = '';
 var i;
 length += start;

 for (i = start; i < length; i += 1) {
 str += fromCharCode(dataView.getUint8(i));
 }

 return str;
 }

 var REGEXP_DATA_URL_HEAD = /^data:.*,/;

 /**
 * Transform Data URL to array buffer.
 * @param {string} dataURL - The Data URL to transform.
 * @returns {ArrayBuffer} The result array buffer.
 */

 function dataURLToArrayBuffer(dataURL) {
 var base = dataURL.replace(REGEXP_DATA_URL_HEAD, '');
 var binary = atob(base);
 var arrayBuffer = new ArrayBuffer(binary.length);
 var uint8 = new Uint8Array(arrayBuffer);
 forEach(uint8, function (value, i) {
 uint8[i] = binary.charCodeAt(i);
 });
 return arrayBuffer;
 }

 /**
 * Transform array buffer to Data URL.
 * @param {ArrayBuffer} arrayBuffer - The array buffer to transform.
 * @param {string} mimeType - The mime type of the Data URL.
 * @returns {string} The result Data URL.
 */

 function arrayBufferToDataURL(arrayBuffer, mimeType) {
 var chunks = [];
 var chunkSize = 8192;
 var uint8 = new Uint8Array(arrayBuffer);

 while (uint8.length > 0) {
 chunks.push(fromCharCode.apply(void 0, _toConsumableArray(uint8.subarray(0, chunkSize))));
 uint8 = uint8.subarray(chunkSize);
 }

 return "data:".concat(mimeType, ";base,").concat(btoa(chunks.join('')));
 }

 /**
 * Get orientation value from given array buffer.
 * @param {ArrayBuffer} arrayBuffer - The array buffer to read.
 * @returns {number} The read orientation value.
 */

 function resetAndGetOrientation(arrayBuffer) {
 var dataView = new DataView(arrayBuffer);
 var orientation; // Ignores range error when the image does not have correct Exif information

 try {
 var littleEndian;
 var app1Start;
 var ifdStart; // Only handle JPEG image (start by 0xFFD8)

 if (dataView.getUint8(0) === 0xFF && dataView.getUint8(1) === 0xD8) {
 var length = dataView.byteLength;
 var offset = 2;

 while (offset + 1 < length) {
 if (dataView.getUint8(offset) === 0xFF && dataView.getUint8(offset + 1) === 0xE1) {
 app1Start = offset;
 break;
 }

 offset += 1;
 }
 }

 if (app1Start) {
 var exifIDCode = app1Start + 4;
 var tiffOffset = app1Start + 10;

 if (getStringFromCharCode(dataView, exifIDCode, 4) === 'Exif') {
 var endianness = dataView.getUint16(tiffOffset);
 littleEndian = endianness === 0x4949;

 if (littleEndian || endianness === 0x4D4D
 /* bigEndian */
 ) {
 if (dataView.getUint16(tiffOffset + 2, littleEndian) === 0x002A) {
 var firstIFDOffset = dataView.getUint32(tiffOffset + 4, littleEndian);

 if (firstIFDOffset >= 0x00000008) {
 ifdStart = tiffOffset + firstIFDOffset;
 }
 }
 }
 }
 }

 if (ifdStart) {
 var _length = dataView.getUint16(ifdStart, littleEndian);

 var _offset;

 var i;

 for (i = 0; i < _length; i += 1) {
 _offset = ifdStart + i * 12 + 2;

 if (dataView.getUint16(_offset, littleEndian) === 0x0112
 /* Orientation */
 ) {
 // 8 is the offset of the current tag's value
 _offset += 8; // Get the original orientation value

 orientation = dataView.getUint16(_offset, littleEndian); // Override the orientation with its default value

 dataView.setUint16(_offset, 1, littleEndian);
 break;
 }
 }
 }
 } catch (e) {
 orientation = 1;
 }

 return orientation;
 }

 /**
 * Parse Exif Orientation value.
 * @param {number} orientation - The orientation to parse.
 * @returns {Object} The parsed result.
 */

 function parseOrientation(orientation) {
 var rotate = 0;
 var scaleX = 1;
 var scaleY = 1;

 switch (orientation) {
 // Flip horizontal
 case 2:
 scaleX = -1;
 break;
 // Rotate left 180°

 case 3:
 rotate = -180;
 break;
 // Flip vertical

 case 4:
 scaleY = -1;
 break;
 // Flip vertical and rotate right 90°

 case 5:
 rotate = 90;
 scaleY = -1;
 break;
 // Rotate right 90°

 case 6:
 rotate = 90;
 break;
 // Flip horizontal and rotate right 90°

 case 7:
 rotate = 90;
 scaleX = -1;
 break;
 // Rotate left 90°

 case 8:
 rotate = -90;
 break;

 default:
 }

 return {
 rotate: rotate,
 scaleX: scaleX,
 scaleY: scaleY
 };
 }

 var render = {
 render: function render() {
 this.initContainer();
 this.initCanvas();
 this.initCropBox();
 this.renderCanvas();

 if (this.cropped) {
 this.renderCropBox();
 }
 },
 initContainer: function initContainer() {
 var element = this.element,
 options = this.options,
 container = this.container,
 cropper = this.cropper;
 addClass(cropper, CLASS_HIDDEN);
 removeClass(element, CLASS_HIDDEN);
 var containerData = {
 width: Math.max(container.offsetWidth, Number(options.minContainerWidth) || 200),
 height: Math.max(container.offsetHeight, Number(options.minContainerHeight) || 100)
 };
 this.containerData = containerData;
 setStyle(cropper, {
 width: containerData.width,
 height: containerData.height
 });
 addClass(element, CLASS_HIDDEN);
 removeClass(cropper, CLASS_HIDDEN);
 },
 // Canvas (image wrapper)
 initCanvas: function initCanvas() {
 var containerData = this.containerData,
 imageData = this.imageData;
 var viewMode = this.options.viewMode;
 var rotated = Math.abs(imageData.rotate) % 180 === 90;
 var naturalWidth = rotated ? imageData.naturalHeight : imageData.naturalWidth;
 var naturalHeight = rotated ? imageData.naturalWidth : imageData.naturalHeight;
 var aspectRatio = naturalWidth / naturalHeight;
 var canvasWidth = containerData.width;
 var canvasHeight = containerData.height;

 if (containerData.height * aspectRatio > containerData.width) {
 if (viewMode === 3) {
 canvasWidth = containerData.height * aspectRatio;
 } else {
 canvasHeight = containerData.width / aspectRatio;
 }
 } else if (viewMode === 3) {
 canvasHeight = containerData.width / aspectRatio;
 } else {
 canvasWidth = containerData.height * aspectRatio;
 }

 var canvasData = {
 aspectRatio: aspectRatio,
 naturalWidth: naturalWidth,
 naturalHeight: naturalHeight,
 width: canvasWidth,
 height: canvasHeight
 };
 canvasData.left = (containerData.width - canvasWidth) / 2;
 canvasData.top = (containerData.height - canvasHeight) / 2;
 canvasData.oldLeft = canvasData.left;
 canvasData.oldTop = canvasData.top;
 this.canvasData = canvasData;
 this.limited = viewMode === 1 || viewMode === 2;
 this.limitCanvas(true, true);
 this.initialImageData = assign({}, imageData);
 this.initialCanvasData = assign({}, canvasData);
 },
 limitCanvas: function limitCanvas(sizeLimited, positionLimited) {
 var options = this.options,
 containerData = this.containerData,
 canvasData = this.canvasData,
 cropBoxData = this.cropBoxData;
 var viewMode = options.viewMode;
 var aspectRatio = canvasData.aspectRatio;
 var cropped = this.cropped && cropBoxData;

 if (sizeLimited) {
 var minCanvasWidth = Number(options.minCanvasWidth) || 0;
 var minCanvasHeight = Number(options.minCanvasHeight) || 0;

 if (viewMode > 1) {
 minCanvasWidth = Math.max(minCanvasWidth, containerData.width);
 minCanvasHeight = Math.max(minCanvasHeight, containerData.height);

 if (viewMode === 3) {
 if (minCanvasHeight * aspectRatio > minCanvasWidth) {
 minCanvasWidth = minCanvasHeight * aspectRatio;
 } else {
 minCanvasHeight = minCanvasWidth / aspectRatio;
 }
 }
 } else if (viewMode > 0) {
 if (minCanvasWidth) {
 minCanvasWidth = Math.max(minCanvasWidth, cropped ? cropBoxData.width : 0);
 } else if (minCanvasHeight) {
 minCanvasHeight = Math.max(minCanvasHeight, cropped ? cropBoxData.height : 0);
 } else if (cropped) {
 minCanvasWidth = cropBoxData.width;
 minCanvasHeight = cropBoxData.height;

 if (minCanvasHeight * aspectRatio > minCanvasWidth) {
 minCanvasWidth = minCanvasHeight * aspectRatio;
 } else {
 minCanvasHeight = minCanvasWidth / aspectRatio;
 }
 }
 }

 var _getAdjustedSizes = getAdjustedSizes({
 aspectRatio: aspectRatio,
 width: minCanvasWidth,
 height: minCanvasHeight
 });

 minCanvasWidth = _getAdjustedSizes.width;
 minCanvasHeight = _getAdjustedSizes.height;
 canvasData.minWidth = minCanvasWidth;
 canvasData.minHeight = minCanvasHeight;
 canvasData.maxWidth = Infinity;
 canvasData.maxHeight = Infinity;
 }

 if (positionLimited) {
 if (viewMode > (cropped ? 0 : 1)) {
 var newCanvasLeft = containerData.width - canvasData.width;
 var newCanvasTop = containerData.height - canvasData.height;
 canvasData.minLeft = Math.min(0, newCanvasLeft);
 canvasData.minTop = Math.min(0, newCanvasTop);
 canvasData.maxLeft = Math.max(0, newCanvasLeft);
 canvasData.maxTop = Math.max(0, newCanvasTop);

 if (cropped && this.limited) {
 canvasData.minLeft = Math.min(cropBoxData.left, cropBoxData.left + (cropBoxData.width - canvasData.width));
 canvasData.minTop = Math.min(cropBoxData.top, cropBoxData.top + (cropBoxData.height - canvasData.height));
 canvasData.maxLeft = cropBoxData.left;
 canvasData.maxTop = cropBoxData.top;

 if (viewMode === 2) {
 if (canvasData.width >= containerData.width) {
 canvasData.minLeft = Math.min(0, newCanvasLeft);
 canvasData.maxLeft = Math.max(0, newCanvasLeft);
 }

 if (canvasData.height >= containerData.height) {
 canvasData.minTop = Math.min(0, newCanvasTop);
 canvasData.maxTop = Math.max(0, newCanvasTop);
 }
 }
 }
 } else {
 canvasData.minLeft = -canvasData.width;
 canvasData.minTop = -canvasData.height;
 canvasData.maxLeft = containerData.width;
 canvasData.maxTop = containerData.height;
 }
 }
 },
 renderCanvas: function renderCanvas(changed, transformed) {
 var canvasData = this.canvasData,
 imageData = this.imageData;

 if (transformed) {
 var _getRotatedSizes = getRotatedSizes({
 width: imageData.naturalWidth * Math.abs(imageData.scaleX || 1),
 height: imageData.naturalHeight * Math.abs(imageData.scaleY || 1),
 degree: imageData.rotate || 0
 }),
 naturalWidth = _getRotatedSizes.width,
 naturalHeight = _getRotatedSizes.height;

 var width = canvasData.width * (naturalWidth / canvasData.naturalWidth);
 var height = canvasData.height * (naturalHeight / canvasData.naturalHeight);
 canvasData.left -= (width - canvasData.width) / 2;
 canvasData.top -= (height - canvasData.height) / 2;
 canvasData.width = width;
 canvasData.height = height;
 canvasData.aspectRatio = naturalWidth / naturalHeight;
 canvasData.naturalWidth = naturalWidth;
 canvasData.naturalHeight = naturalHeight;
 this.limitCanvas(true, false);
 }

 if (canvasData.width > canvasData.maxWidth || canvasData.width < canvasData.minWidth) {
 canvasData.left = canvasData.oldLeft;
 }

 if (canvasData.height > canvasData.maxHeight || canvasData.height < canvasData.minHeight) {
 canvasData.top = canvasData.oldTop;
 }

 canvasData.width = Math.min(Math.max(canvasData.width, canvasData.minWidth), canvasData.maxWidth);
 canvasData.height = Math.min(Math.max(canvasData.height, canvasData.minHeight), canvasData.maxHeight);
 this.limitCanvas(false, true);
 canvasData.left = Math.min(Math.max(canvasData.left, canvasData.minLeft), canvasData.maxLeft);
 canvasData.top = Math.min(Math.max(canvasData.top, canvasData.minTop), canvasData.maxTop);
 canvasData.oldLeft = canvasData.left;
 canvasData.oldTop = canvasData.top;
 setStyle(this.canvas, assign({
 width: canvasData.width,
 height: canvasData.height
 }, getTransforms({
 translateX: canvasData.left,
 translateY: canvasData.top
 })));
 this.renderImage(changed);

 if (this.cropped && this.limited) {
 this.limitCropBox(true, true);
 }
 },
 renderImage: function renderImage(changed) {
 var canvasData = this.canvasData,
 imageData = this.imageData;
 var width = imageData.naturalWidth * (canvasData.width / canvasData.naturalWidth);
 var height = imageData.naturalHeight * (canvasData.height / canvasData.naturalHeight);
 assign(imageData, {
 width: width,
 height: height,
 left: (canvasData.width - width) / 2,
 top: (canvasData.height - height) / 2
 });
 setStyle(this.image, assign({
 width: imageData.width,
 height: imageData.height
 }, getTransforms(assign({
 translateX: imageData.left,
 translateY: imageData.top
 }, imageData))));

 if (changed) {
 this.output();
 }
 },
 initCropBox: function initCropBox() {
 var options = this.options,
 canvasData = this.canvasData;
 var aspectRatio = options.aspectRatio || options.initialAspectRatio;
 var autoCropArea = Number(options.autoCropArea) || 0.8;
 var cropBoxData = {
 width: canvasData.width,
 height: canvasData.height
 };

 if (aspectRatio) {
 if (canvasData.height * aspectRatio > canvasData.width) {
 cropBoxData.height = cropBoxData.width / aspectRatio;
 } else {
 cropBoxData.width = cropBoxData.height * aspectRatio;
 }
 }

 this.cropBoxData = cropBoxData;
 this.limitCropBox(true, true); // Initialize auto crop area

 cropBoxData.width = Math.min(Math.max(cropBoxData.width, cropBoxData.minWidth), cropBoxData.maxWidth);
 cropBoxData.height = Math.min(Math.max(cropBoxData.height, cropBoxData.minHeight), cropBoxData.maxHeight); // The width/height of auto crop area must large than "minWidth/Height"

 cropBoxData.width = Math.max(cropBoxData.minWidth, cropBoxData.width * autoCropArea);
 cropBoxData.height = Math.max(cropBoxData.minHeight, cropBoxData.height * autoCropArea);
 cropBoxData.left = canvasData.left + (canvasData.width - cropBoxData.width) / 2;
 cropBoxData.top = canvasData.top + (canvasData.height - cropBoxData.height) / 2;
 cropBoxData.oldLeft = cropBoxData.left;
 cropBoxData.oldTop = cropBoxData.top;
 this.initialCropBoxData = assign({}, cropBoxData);
 },
 limitCropBox: function limitCropBox(sizeLimited, positionLimited) {
 var options = this.options,
 containerData = this.containerData,
 canvasData = this.canvasData,
 cropBoxData = this.cropBoxData,
 limited = this.limited;
 var aspectRatio = options.aspectRatio;

 if (sizeLimited) {
 var minCropBoxWidth = Number(options.minCropBoxWidth) || 0;
 var minCropBoxHeight = Number(options.minCropBoxHeight) || 0;
 var maxCropBoxWidth = limited ? Math.min(containerData.width, canvasData.width, canvasData.width + canvasData.left, containerData.width - canvasData.left) : containerData.width;
 var maxCropBoxHeight = limited ? Math.min(containerData.height, canvasData.height, canvasData.height + canvasData.top, containerData.height - canvasData.top) : containerData.height; // The min/maxCropBoxWidth/Height must be less than container's width/height

 minCropBoxWidth = Math.min(minCropBoxWidth, containerData.width);
 minCropBoxHeight = Math.min(minCropBoxHeight, containerData.height);

 if (aspectRatio) {
 if (minCropBoxWidth && minCropBoxHeight) {
 if (minCropBoxHeight * aspectRatio > minCropBoxWidth) {
 minCropBoxHeight = minCropBoxWidth / aspectRatio;
 } else {
 minCropBoxWidth = minCropBoxHeight * aspectRatio;
 }
 } else if (minCropBoxWidth) {
 minCropBoxHeight = minCropBoxWidth / aspectRatio;
 } else if (minCropBoxHeight) {
 minCropBoxWidth = minCropBoxHeight * aspectRatio;
 }

 if (maxCropBoxHeight * aspectRatio > maxCropBoxWidth) {
 maxCropBoxHeight = maxCropBoxWidth / aspectRatio;
 } else {
 maxCropBoxWidth = maxCropBoxHeight * aspectRatio;
 }
 } // The minWidth/Height must be less than maxWidth/Height


 cropBoxData.minWidth = Math.min(minCropBoxWidth, maxCropBoxWidth);
 cropBoxData.minHeight = Math.min(minCropBoxHeight, maxCropBoxHeight);
 cropBoxData.maxWidth = maxCropBoxWidth;
 cropBoxData.maxHeight = maxCropBoxHeight;
 }

 if (positionLimited) {
 if (limited) {
 cropBoxData.minLeft = Math.max(0, canvasData.left);
 cropBoxData.minTop = Math.max(0, canvasData.top);
 cropBoxData.maxLeft = Math.min(containerData.width, canvasData.left + canvasData.width) - cropBoxData.width;
 cropBoxData.maxTop = Math.min(containerData.height, canvasData.top + canvasData.height) - cropBoxData.height;
 } else {
 cropBoxData.minLeft = 0;
 cropBoxData.minTop = 0;
 cropBoxData.maxLeft = containerData.width - cropBoxData.width;
 cropBoxData.maxTop = containerData.height - cropBoxData.height;
 }
 }
 },
 renderCropBox: function renderCropBox() {
 var options = this.options,
 containerData = this.containerData,
 cropBoxData = this.cropBoxData;

 if (cropBoxData.width > cropBoxData.maxWidth || cropBoxData.width < cropBoxData.minWidth) {
 cropBoxData.left = cropBoxData.oldLeft;
 }

 if (cropBoxData.height > cropBoxData.maxHeight || cropBoxData.height < cropBoxData.minHeight) {
 cropBoxData.top = cropBoxData.oldTop;
 }

 cropBoxData.width = Math.min(Math.max(cropBoxData.width, cropBoxData.minWidth), cropBoxData.maxWidth);
 cropBoxData.height = Math.min(Math.max(cropBoxData.height, cropBoxData.minHeight), cropBoxData.maxHeight);
 this.limit 




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