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https://gitee.com/elegant_wings/dbd-meeting-wx-small.git
synced 2025-06-22 03:09:37 +08:00
546 lines
16 KiB
JavaScript
546 lines
16 KiB
JavaScript
/**
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* wx-cropper 2.0
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* 基于微信小程序的图片裁剪工具
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* @author ifmiss
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*/
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// 裁剪图片的宽度设置
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const CROPPER_WIDTH = 720
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// 裁剪显示的最大比例，如果裁剪的图片过长，则做限制，默认最大宽高比例为 宽640 / 高960 (宽高比例)
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const CROPPER_RATIO = 0.7
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/**
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* 初始化裁剪的比例 如果是正方形则是 1
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* 比例为宽高比 建议区间为 0.25 - 4
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* 设置为0的时候则是不固定宽高
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*/
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const CROPPER_AREA_RATIO = 1
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// 裁剪的位置
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let CUT_L, // 初始化拖拽元素的left值
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CUT_T, // 初始化拖拽元素的top值
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CUT_R, // 初始化拖拽元素的
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CUT_B, // 初始化拖拽元素的
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// 裁剪的宽度
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CUT_W, // 初始化拖拽元素的宽度
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CUT_H, // 初始化拖拽元素的高度
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// 拖拽相关
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PAGE_X, // 手按下的x位置
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PAGE_Y, // 手按下y的位置
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T_PAGE_X, // 手移动的时候x的位置
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T_PAGE_Y, // 手移动的时候Y的位置x
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// 图片比例
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IMG_RATIO,
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// 图片实际宽高
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IMG_REAL_W, // 图片实际的宽度
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IMG_REAL_H, // 图片实际的高度
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// 裁剪图片区域的信息
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CROPPER_IMG_W,
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CROPPER_IMG_H,
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// 移动的比例
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DRAFG_MOVE_RATIO = 750 / wx.getSystemInfoSync().windowWidth, //移动时候的比例,
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INIT_DRAG_POSITION = 0, // 初始化屏幕宽度和裁剪区域的宽度之差，用于设置初始化裁剪的宽度
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DRAW_IMAGE_W, // 设置生成的图片宽度
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// 最大可显示得图片宽度，需要设定最大值，否则安卓部分机器会闪退, 控制qualityWidth的最大值
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maxQW = 2550
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/**
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* 最小裁剪宽度 由于设置了裁剪的UI样式，裁剪的宽高必须要有最小宽度，这个宽度是裁剪长或者宽的最短一方的宽度
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* 如 400 200
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* 那么如果只能设置为100的时候
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* 那么最小缩放到200 100的效果，之后只能放大不能缩小
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*/
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const MIN_CROPPER_DIS = 100
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const app = getApp()
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Page({
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/**
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* 页面的初始数据
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*/
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data: {
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// 之后可以动态替换
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// imageSrc: 'http://www.bing.com/az/hprichbg/rb/BulgariaPerseids_ZH-CN11638911564_1920x1080.jpg',
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// imageSrc: 'http://www.bing.com/az/hprichbg/rb/BulgariaPerseids_ZH-CN11638911564_1920x1080.jpg',
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imageSrc: '/images/vcard.png',
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// 是否显示图片(在图片加载完成之后设置为true)
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isShowImg: false,
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// 初始化的宽高
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cropperInitW: CROPPER_WIDTH,
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cropperInitH: CROPPER_WIDTH,
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// 动态的宽高
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cropperW: CROPPER_WIDTH,
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cropperH: CROPPER_WIDTH,
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// 动态的left top值
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cropperL: 0,
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cropperT: 0,
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// 图片缩放值
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scaleP: 0,
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// 裁剪框 宽高
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cutL: 0,
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cutT: 0,
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cutB: 0,
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cutR: 0,
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qualityWidth: DRAW_IMAGE_W,
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innerAspectRadio: DRAFG_MOVE_RATIO
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},
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/**
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* 生命周期函数--监听页面加载
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*/
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onLoad: function (e) {
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this.setData({
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imageSrc: e.img
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})
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},
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/**
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* 生命周期函数--监听页面初次渲染完成
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*/
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onReady: function () {
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// 初始化
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this.loadImage();
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},
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/**
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* 选择本地图片
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* 基于底部中间的按钮的点击事件
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*/
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getImage: function () {
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var _this = this
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wx.chooseImage({
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success: function (res) {
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_this.setData({
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isShowImg: false,
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imageSrc: res.tempFilePaths[0],
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})
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_this.loadImage();
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},
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})
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},
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/**
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* 初始化图片信息
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* 获取图片内容，并初始化裁剪框
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*/
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loadImage: function () {
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var _this = this
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wx.showLoading({
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title: '图片加载中...',
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})
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wx.getImageInfo({
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src: _this.data.imageSrc,
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success: function success(res) {
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DRAW_IMAGE_W = IMG_REAL_W = res.width
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IMG_REAL_H = res.height
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IMG_RATIO = IMG_REAL_W / IMG_REAL_H
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let MIN_RANGE = IMG_REAL_W > IMG_REAL_H ? IMG_REAL_W : IMG_REAL_H
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// 用于设置图片的比例(以设置裁剪的比例，方便定位裁剪的left right top bottom)
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INIT_DRAG_POSITION = MIN_RANGE > INIT_DRAG_POSITION ? INIT_DRAG_POSITION : MIN_RANGE
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// 拿到裁剪位置
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let cropperPosition = _this.initCropperPosition(IMG_RATIO, CROPPER_WIDTH)
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// 根据图片的宽高显示不同的效果 保证图片可以正常显示
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if (IMG_RATIO >= 1) {
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_this.setData({
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cropperW: CROPPER_WIDTH,
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cropperH: CROPPER_WIDTH / IMG_RATIO,
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// 初始化left right
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cropperL: Math.ceil((CROPPER_WIDTH - CROPPER_WIDTH) / 2),
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cropperT: 0,
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cutL: cropperPosition.left,
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cutT: cropperPosition.top,
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cutR: cropperPosition.right,
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cutB: cropperPosition.bottom,
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// 图片缩放值
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scaleP: IMG_REAL_W / CROPPER_WIDTH,
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qualityWidth: DRAW_IMAGE_W > maxQW ? maxQW : DRAW_IMAGE_W,
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innerAspectRadio: IMG_RATIO
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})
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} else {
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// 此时需要判断图片的比例以设定显示裁剪区域的比例
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// let cropper_real_ratio = CROPPER_RATIO > IMG_RATIO ? CROPPER_RATIO : IMG_RATIO
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if (CROPPER_RATIO > IMG_RATIO) {
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CROPPER_IMG_W = CROPPER_WIDTH / CROPPER_RATIO * IMG_RATIO
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CROPPER_IMG_H = CROPPER_WIDTH / CROPPER_RATIO
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} else {
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CROPPER_IMG_W = CROPPER_WIDTH
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CROPPER_IMG_H = CROPPER_IMG_W / IMG_RATIO
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}
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// 动态生成新的CROPPER的真实宽度 高度
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// CROPPER_IMG_W = CROPPER_WIDTH * cropper_real_ratio
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// CROPPER_IMG_H = CROPPER_WIDTH / cropper_real_ratio / IMG_RATIO
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// console.log(cropper_real_ratio)
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// console.log(CROPPER_IMG_W)
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// console.log(CROPPER_IMG_H)
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// console.log(CROPPER_IMG_W / CROPPER_IMG_H)
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_this.setData({
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cropperW: CROPPER_IMG_W,
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cropperH: CROPPER_IMG_H,
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// 初始化left right
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cropperL: Math.ceil((CROPPER_WIDTH - CROPPER_IMG_W) / 2),
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cropperT: 0,
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cutL: cropperPosition.left,
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cutT: cropperPosition.top,
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cutR: cropperPosition.right,
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cutB: cropperPosition.bottom,
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// 图片缩放值
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scaleP: IMG_REAL_W / CROPPER_IMG_W,
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qualityWidth: DRAW_IMAGE_W > maxQW ? maxQW : DRAW_IMAGE_W,
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innerAspectRadio: IMG_RATIO
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})
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}
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_this.setData({
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isShowImg: true
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})
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wx.hideLoading()
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}
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})
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},
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/**
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* 初始化裁剪区域的
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* left right top bottom
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* 需要 CROPPER_AREA_RATIO 来判断
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* @return 返回裁剪的left, right, top bottom的值
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*/
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initCropperPosition(radio) {
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let left = 0,
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right = 0,
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top = 0,
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bottom = 0,
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cropperW,
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cropperH
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// 如果 CROPPER_AREA_RATIO = 0 则不限制固定宽高
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if (CROPPER_AREA_RATIO === 0) return {
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left,
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right,
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top,
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bottom
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}
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// 宽大于等于高
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if (radio >= 1) {
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cropperW = CROPPER_WIDTH
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cropperH = CROPPER_WIDTH / IMG_RATIO
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if (radio > CROPPER_AREA_RATIO) {
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return {
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left: Math.ceil((cropperW - cropperH * CROPPER_AREA_RATIO) / 2),
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right: Math.ceil((cropperW - cropperH * CROPPER_AREA_RATIO) / 2),
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top: 0,
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bottom: 0
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}
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}
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return {
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left: 0,
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right: 0,
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top: Math.ceil((cropperH - cropperW / CROPPER_AREA_RATIO) / 2),
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bottom: Math.ceil((cropperH - cropperW / CROPPER_AREA_RATIO) / 2)
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}
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}
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// 此时需要判断图片的比例以设定显示裁剪区域的比例
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let cropper_real_ratio = CROPPER_RATIO > IMG_RATIO ? CROPPER_RATIO : IMG_RATIO
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// 高大于宽
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cropperW = CROPPER_WIDTH / cropper_real_ratio * IMG_RATIO
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cropperH = CROPPER_WIDTH / cropper_real_ratio
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if (radio < CROPPER_AREA_RATIO) {
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return {
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left: 0,
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right: 0,
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top: Math.ceil((cropperH - cropperW / CROPPER_AREA_RATIO) / 2),
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bottom: Math.ceil((cropperH - cropperW / CROPPER_AREA_RATIO) / 2)
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}
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}
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return {
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left: Math.ceil((cropperW - cropperH * CROPPER_AREA_RATIO) / 2),
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right: Math.ceil((cropperW - cropperH * CROPPER_AREA_RATIO) / 2),
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top: 0,
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bottom: 0
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}
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},
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/**
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* 拖动时候触发的touchStart事件
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*/
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contentStartMove(e) {
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PAGE_X = e.touches[0].pageX
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PAGE_Y = e.touches[0].pageY
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},
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/**
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* 拖动时候触发的touchMove事件
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*/
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contentMoveing(e) {
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var _this = this
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var dragLengthX = (PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
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var dragLengthY = (PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO * DRAFG_MOVE_RATIO
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// 左移右移
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if (dragLengthX > 0) {
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if (this.data.cutL - dragLengthX < 0) dragLengthX = this.data.cutL
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} else {
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if (this.data.cutR + dragLengthX < 0) dragLengthX = -this.data.cutR
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}
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// 上移下移
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if (dragLengthY > 0) {
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if (this.data.cutT - dragLengthY < 0) dragLengthY = this.data.cutT
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} else {
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if (this.data.cutB + dragLengthY < 0) dragLengthY = -this.data.cutB
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}
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this.setData({
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cutL: this.data.cutL - dragLengthX,
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cutT: this.data.cutT - dragLengthY,
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cutR: this.data.cutR + dragLengthX,
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cutB: this.data.cutB + dragLengthY
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})
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PAGE_X = e.touches[0].pageX
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PAGE_Y = e.touches[0].pageY
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},
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contentTouchEnd() {
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},
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/**
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* 点击取消关闭裁剪页面
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*/
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close() {
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// wx.redirectTo()
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},
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/**
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* 点击完成之后
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* 生成图片信息
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*/
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getImageInfo() {
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var _this = this
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wx.showLoading({
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title: '图片生成中...',
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})
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// 将图片写入画布
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const ctx = wx.createCanvasContext('myCanvas')
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let w = this.data.qualityWidth
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let h = this.data.qualityWidth / IMG_RATIO
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ctx.drawImage(_this.data.imageSrc, 0, 0, w, h);
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ctx.draw(true, () => {
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// 获取画布要裁剪的位置和宽度 均为百分比 * 画布中图片的宽度 保证了在微信小程序中裁剪的图片模糊 位置不对的问题
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var canvasW = ((_this.data.cropperW - _this.data.cutL - _this.data.cutR) / _this.data.cropperW) * w
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var canvasH = ((_this.data.cropperH - _this.data.cutT - _this.data.cutB) / _this.data.cropperH) * h
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var canvasL = (_this.data.cutL / _this.data.cropperW) * w
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var canvasT = (_this.data.cutT / _this.data.cropperH) * h
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// 生成图片
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wx.canvasToTempFilePath({
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x: canvasL,
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y: canvasT,
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width: canvasW,
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height: canvasH,
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destWidth: canvasW,
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destHeight: canvasH,
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quality: 0.5,
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canvasId: 'myCanvas',
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success: function (res) {
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wx.hideLoading()
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app.Upload(res.tempFilePath, function (res) {
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if (res.code == 0) {
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app.AjaxRequest('POST', {
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'content-type': 'application/json',
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'Authorization': 'Bearer ' + app.Getopenid()
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}, '/user/profile/update', {
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avatar: res.fileName
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}, function (ret) {
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wx.navigateBack()
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})
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}
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})
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}
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})
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})
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},
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/**
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* 设置大小的时候触发的touchStart事件
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* 存数据
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*/
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dragStart(e) {
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T_PAGE_X = e.touches[0].pageX
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T_PAGE_Y = e.touches[0].pageY
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CUT_L = this.data.cutL
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CUT_R = this.data.cutR
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CUT_B = this.data.cutB
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CUT_T = this.data.cutT
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},
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/**
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* 设置大小的时候触发的touchMove事件
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* 根据dragType判断类型
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* 4个方向的边线拖拽效果
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* 右下角按钮的拖拽效果
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*/
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dragMove(e) {
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var _this = this
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var dragType = e.target.dataset.drag
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switch (dragType) {
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case 'right':
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var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
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if (CUT_R + dragLength < 0) dragLength = -CUT_R
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if (CUT_R + dragLength + MIN_CROPPER_DIS > this.data.cropperW - this.data.cutL) dragLength = (this.data.cropperW - this.data.cutL) - MIN_CROPPER_DIS - CUT_R
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if (CROPPER_AREA_RATIO) {
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// 底部线的限制 不允许超出
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// dragLength 最大不能超过CUT_B
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if (CUT_B + dragLength / CROPPER_AREA_RATIO <= 0) {
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this.setData({
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cutB: 0
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})
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return
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}
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this.setData({
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cutR: CUT_R + dragLength,
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cutB: CUT_B + dragLength / CROPPER_AREA_RATIO
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})
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} else {
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this.setData({
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cutR: CUT_R + dragLength
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})
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}
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break;
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case 'left':
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var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
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if (CUT_L - dragLength < 0) dragLength = CUT_L
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if ((CUT_L - dragLength + MIN_CROPPER_DIS) > (this.data.cropperW - this.data.cutR)) dragLength = CUT_L - (this.data.cropperW - this.data.cutR) + MIN_CROPPER_DIS
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if (CROPPER_AREA_RATIO) {
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// 顶部线的限制 不允许超出
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// dragLength 最大不能超过CUT_T
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if (CUT_T - dragLength / CROPPER_AREA_RATIO < 0) {
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this.setData({
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cutT: 0
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})
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return
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}
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this.setData({
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cutL: CUT_L - dragLength,
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cutT: CUT_T - dragLength / CROPPER_AREA_RATIO
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})
|
||
} else {
|
||
this.setData({
|
||
cutL: CUT_L - dragLength
|
||
})
|
||
}
|
||
break;
|
||
case 'top':
|
||
var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
|
||
if (CUT_T - dragLength < 0) dragLength = CUT_T
|
||
if ((CUT_T - dragLength + MIN_CROPPER_DIS) > this.data.cropperH - this.data.cutB) dragLength = CUT_T - (this.data.cropperH - this.data.cutB) + MIN_CROPPER_DIS
|
||
|
||
if (CROPPER_AREA_RATIO) {
|
||
// left 线的限制 不允许超出
|
||
// dragLength 最大不能超过CUT_L
|
||
if (CUT_L - dragLength * CROPPER_AREA_RATIO < 0) {
|
||
this.setData({
|
||
cutL: 0
|
||
})
|
||
return
|
||
}
|
||
this.setData({
|
||
cutL: CUT_L - dragLength * CROPPER_AREA_RATIO,
|
||
cutT: CUT_T - dragLength
|
||
})
|
||
} else {
|
||
this.setData({
|
||
cutT: CUT_T - dragLength
|
||
})
|
||
}
|
||
break;
|
||
case 'bottom':
|
||
var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
|
||
if (CUT_B + dragLength < 0) dragLength = -CUT_B
|
||
if (CUT_B + dragLength + MIN_CROPPER_DIS > this.data.cropperH - this.data.cutT) dragLength = (this.data.cropperH - this.data.cutT) - MIN_CROPPER_DIS - CUT_B
|
||
|
||
if (CROPPER_AREA_RATIO) {
|
||
// right 线的限制 不允许超出
|
||
// dragLength 最大不能超过 CUT_R
|
||
if (CUT_R + dragLength * CROPPER_AREA_RATIO < 0) {
|
||
this.setData({
|
||
cutR: 0
|
||
})
|
||
return
|
||
}
|
||
this.setData({
|
||
cutR: CUT_R + dragLength * CROPPER_AREA_RATIO,
|
||
cutB: CUT_B + dragLength
|
||
})
|
||
} else {
|
||
this.setData({
|
||
cutB: CUT_B + dragLength
|
||
})
|
||
}
|
||
break;
|
||
case 'rightBottom':
|
||
var dragType = e.target.dataset.drag
|
||
var dragLengthX = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
|
||
var dragLengthY = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
|
||
if (CUT_B + dragLengthY < 0) dragLengthY = -CUT_B
|
||
if (CUT_B + dragLengthY + MIN_CROPPER_DIS > this.data.cropperH - this.data.cutT) dragLengthY = (this.data.cropperH - this.data.cutT) - MIN_CROPPER_DIS - CUT_B
|
||
if (CUT_R + dragLengthX < 0) dragLengthX = -CUT_R
|
||
if (CUT_R + dragLengthX + MIN_CROPPER_DIS > this.data.cropperW - this.data.cutL) dragLengthX = (this.data.cropperW - this.data.cutL) - MIN_CROPPER_DIS - CUT_R
|
||
|
||
if (CROPPER_AREA_RATIO) {
|
||
// right 线的限制 不允许超出
|
||
// dragLength 最大不能超过 CUT_R
|
||
if (CUT_R + dragLengthY * CROPPER_AREA_RATIO < 0) {
|
||
this.setData({
|
||
cutR: 0
|
||
})
|
||
return
|
||
}
|
||
this.setData({
|
||
cutR: CUT_R + dragLengthY * CROPPER_AREA_RATIO,
|
||
cutB: CUT_B + dragLengthY
|
||
})
|
||
} else {
|
||
this.setData({
|
||
cutB: CUT_B + dragLengthY,
|
||
cutR: CUT_R + dragLengthX
|
||
})
|
||
}
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
}) |