738 lines
24 KiB
JavaScript
738 lines
24 KiB
JavaScript
/**
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* 图片编辑器-手势监听
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* 1. 支持编译到app-vue（uni-app 2.5.5及以上版本）、H5上
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*/
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/** 图片偏移量 */
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var offset = { x: 0, y: 0 };
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/** 图片缩放比例 */
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var scale = 1;
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/** 图片最小缩放比例 */
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var minScale = 1;
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/** 图片旋转角度 */
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var rotate = 0;
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/** 触摸点 */
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var touches = [];
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/** 图片布局信息 */
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var img = {};
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/** 系统信息 */
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var sys = {};
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/** 裁剪区域布局信息 */
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var area = {};
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/** 触摸行为类型 */
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var touchType = '';
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/** 操作角的位置 */
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var activeAngle = 0;
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/** 裁剪区域布局信息偏移量 */
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var areaOffset = { left: 0, right: 0, top: 0, bottom: 0 };
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/** 元素ID */
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var elIds = {
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'imageStyles': 'crop-image',
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'maskStylesList': 'crop-mask-block',
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'borderStyles': 'crop-border',
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'circleBoxStyles': 'crop-circle-box',
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'circleStyles': 'crop-circle',
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'gridStylesList': 'crop-grid',
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'angleStylesList': 'crop-angle',
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}
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/** 记录上次初始化时间戳，排除APP重复更新 */
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var timestamp = 0;
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/** vue3 renderjs 条件编译无效，以此方式区别 APP 和 H5 */
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// #ifdef H5
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var platform = 'H5';
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// #endif
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// #ifdef APP
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var platform = 'APP';
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// #endif
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/**
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* 样式对象转字符串
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* @param {Object} style 样式对象
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*/
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function styleToString(style) {
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if(typeof style === 'string') return style;
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var str = '';
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for (let k in style) {
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str += k + ':' + style[k] + ';';
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}
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return str;
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}
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/**
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*
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* @param {Object} instance 页面实例对象
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* @param {Object} key 要修改样式的key
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* @param {Object|Array} style 样式
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*/
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function setStyle(instance, key, style) {
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// console.log('setStyle', instance, key, JSON.stringify(style))
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// #ifdef APP-PLUS
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if(platform === 'APP') {
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if(Object.prototype.toString.call(style) === '[object Array]') {
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for (var i = 0, len = style.length; i < len; i++) {
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var el = window.document.getElementById(elIds[key] + '-' + (i + 1));
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el && (el.style = styleToString(style[i]));
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}
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} else {
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var el = window.document.getElementById(elIds[key]);
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el && (el.style = styleToString(style));
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}
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}
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// #endif
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// #ifdef H5
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if(platform === 'H5') instance[key] = style;
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// #endif
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}
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/**
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* 触发页面实例指定方法
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* @param {Object} instance 页面实例对象
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* @param {Object} name 方法名称
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* @param {Object} obj 传递参数
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*/
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function callMethod(instance, name, obj) {
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// #ifdef APP-PLUS
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if(platform === 'APP') instance.callMethod(name, obj);
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// #endif
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// #ifdef H5
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if(platform === 'H5') instance[name](obj);
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// #endif
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}
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/**
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* 计算两点间距
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* @param {Object} touches 触摸点信息
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*/
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function getDistanceByTouches(touches) {
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// 根据勾股定理求两点间距离
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var a = touches[1].pageX - touches[0].pageX;
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var b = touches[1].pageY - touches[0].pageY;
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var c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));
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// 求两点间的中点坐标
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// 1. a、b可能为负值
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// 2. 在求a、b时，如用touches[1]减touches[0]，则求中点坐标也得用touches[1]减a/2、b/2
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// 3. 同理，在求a、b时，也可用touches[0]减touches[1]，则求中点坐标也得用touches[0]减a/2、b/2
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var x = touches[1].pageX - a / 2;
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var y = touches[1].pageY - b / 2;
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return { c, x, y };
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};
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/**
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* 修正取值
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* @param {Object} a
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* @param {Object} b
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* @param {Object} c
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* @param {Object} reverse 是否反向
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*/
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function correctValue(a, b, c, reverse) {
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return reverse ? Math.max(Math.min(a, b), c) : Math.min(Math.max(a, b), c);
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}
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/**
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* 检查边界：限制 x、y 拖动范围，禁止滑出边界
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* @param {Object} e 点坐标
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*/
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function checkRange(e) {
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var r = rotate / 90 % 2;
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if(r === 1) { // 因图片宽高可能不等，翻转 90° 或 270° 后图片宽高需反着计算，且左右和上下边界要根据差值做偏移
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var o = (img.height - img.width) / 2; // 宽高差值一半
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return {
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x: correctValue(e.x, -img.height + o + area.width + area.left, area.left + o, img.height < area.height),
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y: correctValue(e.y, -img.width - o + area.height + area.top, area.top - o, img.width < area.width)
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}
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}
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return {
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x: correctValue(e.x, -img.width + area.width + area.left, area.left, img.width < area.width),
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y: correctValue(e.y, -img.height + area.height + area.top, area.top, img.height < area.height)
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}
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};
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/**
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* 变更图片布局信息
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* @param {Object} e 布局信息
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*/
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function changeImageRect(e) {
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// console.log('changeImageRect', e)
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offset.x += e.x || 0;
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offset.y += e.y || 0;
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if(e.check && area.checkRange) { // 检查边界
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var point = checkRange(offset);
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if(offset.x !== point.x || offset.y !== point.y) {
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offset = point;
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}
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}
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// 因频繁修改 width/height 会造成大量的内存消耗，改为scale
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// e.instance.imageStyles = {
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// width: img.width + 'px',
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// height: img.height + 'px',
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// transform: 'translate(' + (offset.x + ox) + 'px, ' + (offset.y + ox) + 'px) rotate(' + rotate +'deg)'
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// };
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var ox = (img.width - img.oldWidth) / 2;
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var oy = (img.height - img.oldHeight) / 2;
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// e.instance.imageStyles = {
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// width: img.oldWidth + 'px',
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// height: img.oldHeight + 'px',
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// transform: 'translate(' + (offset.x + ox) + 'px, ' + (offset.y + oy) + 'px) rotate(' + rotate +'deg) scale(' + scale + ')'
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// };
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setStyle(e.instance, 'imageStyles', {
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width: img.oldWidth + 'px',
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height: img.oldHeight + 'px',
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transform: (img.gpu ? 'translateZ(0) ' : '') + 'translate(' + (offset.x + ox) + 'px, ' + (offset.y + oy) + 'px' + ') rotate(' + rotate +'deg) scale(' + scale + ')'
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});
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callMethod(e.instance, 'dataChange', {
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width: img.width,
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height: img.height,
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x: offset.x,
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y: offset.y,
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rotate: rotate
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});
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};
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/**
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* 变更裁剪区域布局信息
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* @param {Object} e 布局信息
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*/
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function changeAreaRect(e) {
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// console.log('changeAreaRect', e)
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// 变更蒙版样式
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setStyle(e.instance, 'maskStylesList', [
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{
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left: 0,
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width: (area.left + areaOffset.left) + 'px',
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top: 0,
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bottom: 0,
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'z-index': area.zIndex + 2
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},
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{
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left: (area.right + areaOffset.right) + 'px',
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right: 0,
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top: 0,
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bottom: 0,
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'z-index': area.zIndex + 2
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},
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{
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left: (area.left + areaOffset.left) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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top: 0,
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height: (area.top + areaOffset.top) + 'px',
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'z-index': area.zIndex + 2
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},
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{
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left: (area.left + areaOffset.left) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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top: (area.bottom + areaOffset.bottom) + 'px',
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// height: (area.top - areaOffset.bottom + sys.offsetBottom) + 'px',
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bottom: 0,
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'z-index': area.zIndex + 2
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}
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]);
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// 变更边框样式
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if(area.showBorder) {
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setStyle(e.instance, 'borderStyles', {
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left: (area.left + areaOffset.left) + 'px',
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top: (area.top + areaOffset.top) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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height: (area.height + areaOffset.bottom - areaOffset.top) + 'px',
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'z-index': area.zIndex + 3
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});
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}
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// 变更参考线样式
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if(area.showGrid) {
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setStyle(e.instance, 'gridStylesList', [
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{
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'border-width': '1px 0 0 0',
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left: (area.left + areaOffset.left) + 'px',
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right: (area.right + areaOffset.right) + 'px',
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top: (area.top + areaOffset.top + (area.height + areaOffset.bottom - areaOffset.top) / 3 - 0.5) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': '1px 0 0 0',
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left: (area.left + areaOffset.left) + 'px',
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right: (area.right + areaOffset.right) + 'px',
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top: (area.top + areaOffset.top + (area.height + areaOffset.bottom - areaOffset.top) * 2 / 3 - 0.5) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': '0 1px 0 0',
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top: (area.top + areaOffset.top) + 'px',
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bottom: (area.bottom + areaOffset.bottom) + 'px',
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left: (area.left + areaOffset.left + (area.width + areaOffset.right - areaOffset.left) / 3 - 0.5) + 'px',
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height: (area.height + areaOffset.bottom - areaOffset.top) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': '0 1px 0 0',
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top: (area.top + areaOffset.top) + 'px',
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bottom: (area.bottom + areaOffset.bottom) + 'px',
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left: (area.left + areaOffset.left + (area.width + areaOffset.right - areaOffset.left) * 2 / 3 - 0.5) + 'px',
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height: (area.height + areaOffset.bottom - areaOffset.top) + 'px',
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'z-index': area.zIndex + 3
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}
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]);
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}
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// 变更四个伸缩角样式
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if(area.showAngle) {
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setStyle(e.instance, 'angleStylesList', [
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{
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'border-width': area.angleBorderWidth + 'px 0 0 ' + area.angleBorderWidth + 'px',
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left: (area.left + areaOffset.left - area.angleBorderWidth) + 'px',
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top: (area.top + areaOffset.top - area.angleBorderWidth) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': area.angleBorderWidth + 'px ' + area.angleBorderWidth + 'px 0 0',
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left: (area.right + areaOffset.right - area.angleSize) + 'px',
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top: (area.top + areaOffset.top - area.angleBorderWidth) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': '0 0 ' + area.angleBorderWidth + 'px ' + area.angleBorderWidth + 'px',
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left: (area.left + areaOffset.left - area.angleBorderWidth) + 'px',
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top: (area.bottom + areaOffset.bottom - area.angleSize) + 'px',
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'z-index': area.zIndex + 3
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},
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{
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'border-width': '0 ' + area.angleBorderWidth + 'px ' + area.angleBorderWidth + 'px 0',
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left: (area.right + areaOffset.right - area.angleSize) + 'px',
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top: (area.bottom + areaOffset.bottom - area.angleSize) + 'px',
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'z-index': area.zIndex + 3
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}
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]);
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}
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// 变更圆角样式
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if(area.radius > 0) {
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var radius = area.radius;
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if(area.width === area.height && area.radius >= area.width / 2) { // 圆形
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radius = (area.width / 2);
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} else { // 圆角矩形
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if(area.width !== area.height) { // 限制圆角半径不能超过短边的一半
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radius = Math.min(area.width / 2, area.height / 2, radius);
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}
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}
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setStyle(e.instance, 'circleBoxStyles', {
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left: (area.left + areaOffset.left) + 'px',
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top: (area.top + areaOffset.top) + 'px',
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width: (area.width + areaOffset.right - areaOffset.left) + 'px',
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height: (area.height + areaOffset.bottom - areaOffset.top) + 'px',
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'z-index': area.zIndex + 2
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});
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setStyle(e.instance, 'circleStyles', {
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'box-shadow': '0 0 0 ' + Math.max(area.width, area.height) + 'px rgba(51, 51, 51, 0.8)',
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'border-radius': radius + 'px'
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});
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}
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};
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/**
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* 缩放图片
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* @param {Object} e 布局信息
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*/
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function scaleImage(e) {
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// console.log('scaleImage', e)
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var last = scale;
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scale = Math.min(Math.max(e.scale + scale, minScale), img.maxScale);
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if(last !== scale) {
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img.width = img.oldWidth * scale;
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img.height = img.oldHeight * scale;
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// 参考问题：有一个长4000px、宽4000px的四方形ABCD，A点的坐标固定在(-2000,-2000)，
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// 该四边形上有一个点E，坐标为(-100,-300)，将该四方形复制一份并缩小到90%后，
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// 新四边形的A点坐标为多少时可使新四边形的E点与原四边形的E点重合？
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// 预期效果：从图中选取某点（参照物）为中心点进行缩放，缩放时无论图像怎么变化，该点位置始终固定不变
|
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// 计算方法：以相同起点先计算缩放前后两点间的距离，再加上原图像偏移量即可
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e.x = (e.x - offset.x) * (1 - scale / last);
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e.y = (e.y - offset.y) * (1 - scale / last);
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changeImageRect(e);
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return true;
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}
|
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return false;
|
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};
|
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/**
|
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* 获取触摸点在哪个角
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* @param {number} x 触摸点x轴坐标
|
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* @param {number} y 触摸点y轴坐标
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* @return {number} 角的位置：0=无；1=左上；2=右上；3=左下；4=右下；
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*/
|
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function getToucheAngle(x, y) {
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// console.log('getToucheAngle', x, y, JSON.stringify(area))
|
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var o = area.angleBorderWidth; // 需扩大触发范围则把 o 值加大即可
|
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var oy = sys.navigation ? 0 : sys.windowTop;
|
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if(y >= area.top - o + oy && y <= area.top + area.angleSize + o + oy) {
|
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if(x >= area.left - o && x <= area.left + area.angleSize + o) {
|
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return 1; // 左上角
|
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} else if(x >= area.right - area.angleSize - o && x <= area.right + o) {
|
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return 2; // 右上角
|
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}
|
||
} else if(y >= area.bottom - area.angleSize - o + oy && y <= area.bottom + o + oy) {
|
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if(x >= area.left - o && x <= area.left + area.angleSize + o) {
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return 3; // 左下角
|
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} else if(x >= area.right - area.angleSize - o && x <= area.right + o) {
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return 4; // 右下角
|
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}
|
||
}
|
||
return 0; // 无触摸到角
|
||
};
|
||
/**
|
||
* 重置数据
|
||
*/
|
||
function resetData() {
|
||
offset = { x: 0, y: 0 };
|
||
scale = 1;
|
||
minScale = img.minScale;
|
||
rotate = 0;
|
||
};
|
||
function getTouchs(touches) {
|
||
var result = [];
|
||
var len = touches ? touches.length : 0
|
||
for (var i = 0; i < len; i++) {
|
||
result[i] = {
|
||
pageX: touches[i].pageX,
|
||
// h5无标题栏时，窗口顶部距离仍为标题栏高度，且触摸点y轴坐标还是有标题栏的值，即减去标题栏高度的值
|
||
pageY: touches[i].pageY + sys.windowTop
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||
};
|
||
}
|
||
return result;
|
||
};
|
||
var mouseEvent = false;
|
||
export default {
|
||
data() {
|
||
return {
|
||
imageStyles: {},
|
||
maskStylesList: [{}, {}, {}, {}],
|
||
borderStyles: {},
|
||
gridStylesList: [{}, {}, {}, {}],
|
||
angleStylesList: [{}, {}, {}, {}],
|
||
circleBoxStyles: {},
|
||
circleStyles: {}
|
||
}
|
||
},
|
||
created() {
|
||
// 监听 PC 端鼠标滚轮
|
||
// #ifdef H5
|
||
platform === 'H5' && window.addEventListener('mousewheel', async (e) => {
|
||
var touchs = getTouchs([e])
|
||
img.src && scaleImage({
|
||
instance: await this.getInstance(),
|
||
check: true,
|
||
// 鼠标向上滚动时，deltaY 固定 -100，鼠标向下滚动时，deltaY 固定 100
|
||
scale: e.deltaY > 0 ? -0.05 : 0.05,
|
||
x: touchs[0].pageX,
|
||
y: touchs[0].pageY
|
||
});
|
||
});
|
||
// #endif
|
||
},
|
||
// #ifdef H5
|
||
mounted() {
|
||
platform === 'H5' && this.initH5Events();
|
||
},
|
||
// #endif
|
||
setPlatform(p) {
|
||
platform = p;
|
||
},
|
||
methods: {
|
||
// #ifdef H5
|
||
getTouchEvent(e) {
|
||
e.touches = [
|
||
{ pageX: e.pageX, pageY: e.pageY }
|
||
];
|
||
return e;
|
||
},
|
||
initH5Events() {
|
||
const preview = document.getElementById('pic-preview');
|
||
preview?.addEventListener('mousedown', (e, ev) => {
|
||
mouseEvent = true;
|
||
this.touchstart(this.getTouchEvent(e));
|
||
});
|
||
preview?.addEventListener('mousemove', (e) => {
|
||
if (!mouseEvent) return;
|
||
this.touchmove(this.getTouchEvent(e));
|
||
});
|
||
preview?.addEventListener('mouseup', (e) => {
|
||
mouseEvent = false;
|
||
this.touchend(this.getTouchEvent(e))
|
||
});
|
||
preview?.addEventListener('mouseleave', (e) => {
|
||
mouseEvent = false;
|
||
this.touchend(this.getTouchEvent(e))
|
||
});
|
||
},
|
||
// #endif
|
||
async getInstance() {
|
||
// #ifdef APP-PLUS
|
||
if(platform === 'APP')
|
||
return this.$ownerInstance
|
||
? Promise.resolve(this.$ownerInstance)
|
||
: new Promise((resolve) => {
|
||
setTimeout(async () => {
|
||
resolve(await this.getInstance());
|
||
});
|
||
});
|
||
// #endif
|
||
// #ifdef H5
|
||
if(platform === 'H5')
|
||
return Promise.resolve(this);
|
||
// #endif
|
||
},
|
||
/**
|
||
* 初始化：观察数据变更
|
||
* @param {Object} newVal 新数据
|
||
* @param {Object} oldVal 旧数据
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
initObserver: async function(newVal, oldVal, o, i) {
|
||
// console.log('initObserver', newVal, oldVal, o, i)
|
||
if(newVal && (!img.src || timestamp !== newVal.timestamp)) {
|
||
timestamp = newVal.timestamp;
|
||
img = newVal.img;
|
||
sys = newVal.sys;
|
||
area = newVal.area;
|
||
minScale = img.minScale;
|
||
resetData();
|
||
const instance = await this.getInstance()
|
||
img.src && changeImageRect({
|
||
instance,
|
||
x: (sys.windowWidth - img.width) / 2,
|
||
y: (sys.windowHeight + sys.windowTop - sys.offsetBottom - img.height) / 2
|
||
});
|
||
changeAreaRect({
|
||
instance
|
||
});
|
||
}
|
||
},
|
||
/**
|
||
* 鼠标滚轮滚动
|
||
* @param {Object} e 事件对象
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
mousewheel: function(e, o) {
|
||
// h5平台 wheel 事件无法判断滚轮滑动方向，需使用 mousewheel
|
||
},
|
||
/**
|
||
* 触摸开始
|
||
* @param {Object} e 事件对象
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
touchstart: function(e, o) {
|
||
if(!img.src) return;
|
||
touches = getTouchs(e.touches);
|
||
activeAngle = area.showAngle ? getToucheAngle(touches[0].pageX, touches[0].pageY) : 0;
|
||
if(touches.length === 1 && activeAngle !== 0) {
|
||
touchType = 'stretch'; // 伸缩裁剪区域
|
||
} else {
|
||
touchType = '';
|
||
}
|
||
// console.log('touchstart', e, activeAngle)
|
||
},
|
||
/**
|
||
* 触摸移动
|
||
* @param {Object} e 事件对象
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
touchmove: async function(e, o) {
|
||
if(!img.src) return;
|
||
// console.log('touchmove', e, o)
|
||
e.touches = getTouchs(e.touches);
|
||
if(touchType === 'stretch') { // 触摸四个角进行拉伸
|
||
var point = e.touches[0];
|
||
var start = touches[0];
|
||
var x = point.pageX - start.pageX;
|
||
var y = point.pageY - start.pageY;
|
||
if(x !== 0 || y !== 0) {
|
||
var maxX = area.width * (1 - area.minScale);
|
||
var maxY = area.height * (1 - area.minScale);
|
||
// console.log(x, y, maxX, maxY, offset, area)
|
||
touches[0] = point;
|
||
switch(activeAngle) {
|
||
case 1: // 左上角
|
||
x += areaOffset.left;
|
||
y += areaOffset.top;
|
||
// console.log(x, y, offset.left > area.left)
|
||
// console.log(maxX, maxY)
|
||
if(x >= 0 && y >= 0) { // 有效滑动
|
||
var max = minScale < 1 && area.checkRange && ((offset.x > 0 && offset.x >= area.left) || (offset.y > 0 && offset.y >= area.top))
|
||
? Math.min(offset.y - area.top, offset.x - area.left)
|
||
: false;
|
||
if(x > y) { // 以x轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxX = max;
|
||
if(x > maxX) x = maxX;
|
||
y = x * area.height / area.width;
|
||
} else { // 以y轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxY = max;
|
||
if(y > maxY) y = maxY;
|
||
x = y * area.width / area.height;
|
||
}
|
||
areaOffset.left = x;
|
||
areaOffset.top = y;
|
||
}
|
||
break;
|
||
case 2: // 右上角
|
||
x += areaOffset.right;
|
||
y += areaOffset.top;
|
||
if(x <= 0 && y >= 0) { // 有效滑动
|
||
var max = minScale < 1 && area.checkRange && ((offset.x > 0 && offset.x + img.width <= area.right) || (offset.y > 0 && offset.y >= area.top))
|
||
? Math.min(offset.y - area.top, area.right - offset.x - img.width)
|
||
: false;
|
||
if(-x > y) { // 以x轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxX = max;
|
||
if(-x > maxX) x = -maxX;
|
||
y = -x * area.height / area.width;
|
||
} else { // 以y轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxY = max;
|
||
if(y > maxY) y = maxY;
|
||
x = -y * area.width / area.height;
|
||
}
|
||
areaOffset.right = x;
|
||
areaOffset.top = y;
|
||
}
|
||
break;
|
||
case 3: // 左下角
|
||
x += areaOffset.left;
|
||
y += areaOffset.bottom;
|
||
if(x >= 0 && y <= 0) { // 有效滑动
|
||
var max = minScale < 1 && area.checkRange && ((offset.x > 0 && offset.x >= area.left) || (offset.y > 0 && offset.y + img.height <= area.bottom))
|
||
? Math.min(area.bottom - offset.y - img.height, offset.x - area.left)
|
||
: false;
|
||
if(x > -y) { // 以x轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxX = max;
|
||
if(x > maxX) x = maxX;
|
||
y = -x * area.height / area.width;
|
||
} else { // 以y轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxY = max;
|
||
if(-y > maxY) y = -maxY;
|
||
x = -y * area.width / area.height;
|
||
}
|
||
areaOffset.left = x;
|
||
areaOffset.bottom = y;
|
||
}
|
||
break;
|
||
case 4: // 右下角
|
||
x += areaOffset.right;
|
||
y += areaOffset.bottom;
|
||
if(x <= 0 && y <= 0) { // 有效滑动
|
||
var max = minScale < 1 && area.checkRange && ((offset.x > 0 && offset.x + img.width <= area.right) || (offset.y > 0 && offset.y + img.height <= area.bottom))
|
||
? Math.min(area.bottom - offset.y - img.height, area.right - offset.x - img.width)
|
||
: false;
|
||
if(-x > -y) { // 以x轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxX = max;
|
||
if(-x > maxX) x = -maxX;
|
||
y = x * area.height / area.width;
|
||
} else { // 以y轴滑动距离为缩放基准
|
||
if(typeof max === 'number') maxY = max;
|
||
if(-y > maxY) y = -maxY;
|
||
x = y * area.width / area.height;
|
||
}
|
||
areaOffset.right = x;
|
||
areaOffset.bottom = y;
|
||
}
|
||
break;
|
||
}
|
||
// console.log(x, y, JSON.stringify(areaOffset))
|
||
changeAreaRect({
|
||
instance: await this.getInstance(),
|
||
});
|
||
// this.draw();
|
||
}
|
||
} else if (e.touches.length == 2) { // 双点触摸缩放
|
||
var start = getDistanceByTouches(touches);
|
||
var end = getDistanceByTouches(e.touches);
|
||
scaleImage({
|
||
instance: await this.getInstance(),
|
||
check: !area.bounce,
|
||
scale: (end.c - start.c) / 100,
|
||
x: end.x,
|
||
y: end.y
|
||
});
|
||
touchType = 'scale';
|
||
} else if(touchType === 'scale') {// 从双点触摸变成单点触摸 / 从缩放变成拖动
|
||
touchType = 'move';
|
||
} else {
|
||
changeImageRect({
|
||
instance: await this.getInstance(),
|
||
check: !area.bounce,
|
||
x: e.touches[0].pageX - touches[0].pageX,
|
||
y: e.touches[0].pageY - touches[0].pageY
|
||
});
|
||
touchType = 'move';
|
||
}
|
||
touches = e.touches;
|
||
},
|
||
/**
|
||
* 触摸结束
|
||
* @param {Object} e 事件对象
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
touchend: async function(e, o) {
|
||
if(!img.src) return;
|
||
if(touchType === 'stretch') { // 拉伸裁剪区域的四个角缩放
|
||
// 裁剪区域宽度被缩放到多少
|
||
var left = areaOffset.left;
|
||
var right = areaOffset.right;
|
||
var top = areaOffset.top;
|
||
var bottom = areaOffset.bottom;
|
||
var w = area.width + right - left;
|
||
var h = area.height + bottom - top;
|
||
// 图像放大倍数
|
||
var p = scale * (area.width / w) - scale;
|
||
// 复原裁剪区域
|
||
areaOffset = { left: 0, right: 0, top: 0, bottom: 0 };
|
||
changeAreaRect({
|
||
instance: await this.getInstance(),
|
||
});
|
||
scaleImage({
|
||
instance: await this.getInstance(),
|
||
scale: p,
|
||
x: area.left + left + (1 === activeAngle || 3 === activeAngle ? w : 0),
|
||
y: area.top + top + (1 === activeAngle || 2 === activeAngle ? h : 0)
|
||
});
|
||
} else if (area.bounce) { // 检查边界并矫正，实现拖动到边界时有回弹效果
|
||
changeImageRect({
|
||
instance: await this.getInstance(),
|
||
check: true
|
||
});
|
||
}
|
||
},
|
||
/**
|
||
* 顺时针翻转图片90°
|
||
* @param {Object} e 事件对象
|
||
* @param {Object} o 组件实例对象
|
||
*/
|
||
rotateImage: async function(r) {
|
||
rotate = (rotate + (r || 90)) % 360;
|
||
|
||
if(img.minScale >= 1) {
|
||
// 因图片宽高可能不等，翻转后图片宽高需足够填满裁剪区域
|
||
minScale = 1;
|
||
if(img.width < area.height) {
|
||
minScale = area.height / img.oldWidth;
|
||
} else if(img.height < area.width) {
|
||
minScale = (area.width / img.oldHeight)
|
||
}
|
||
if(minScale !== 1) {
|
||
scaleImage({
|
||
instance: await this.getInstance(),
|
||
scale: minScale - scale,
|
||
x: sys.windowWidth / 2,
|
||
y: (sys.windowHeight - sys.offsetBottom) / 2
|
||
});
|
||
}
|
||
}
|
||
|
||
// 由于拖动画布后会导致图片位置偏移，翻转时的旋转中心点需是图片区域+偏移区域的中心点
|
||
// 翻转x轴中心点 = (超出裁剪区域右侧的图片宽度 - 超出裁剪区域左侧的图片宽度) / 2
|
||
// 翻转y轴中心点 = (超出裁剪区域下方的图片宽度 - 超出裁剪区域上方的图片宽度) / 2
|
||
var ox = ((offset.x + img.width - area.right) - (area.left - offset.x)) / 2;
|
||
var oy = ((offset.y + img.height - area.bottom) - (area.top - offset.y)) / 2;
|
||
changeImageRect({
|
||
instance: await this.getInstance(),
|
||
check: true,
|
||
x: -ox - oy,
|
||
y: -oy + ox
|
||
});
|
||
},
|
||
rotateImage90: function() {
|
||
this.rotateImage(90)
|
||
},
|
||
rotateImage270: function() {
|
||
this.rotateImage(270)
|
||
},
|
||
}
|
||
} |