@jdcfe/yep-react/es/scratch/index.js

一套移动端的React组件库

import _classCallCheck from "@babel/runtime/helpers/classCallCheck";
import _createClass from "@babel/runtime/helpers/createClass";
import _assertThisInitialized from "@babel/runtime/helpers/assertThisInitialized";
import _inherits from "@babel/runtime/helpers/inherits";
import _possibleConstructorReturn from "@babel/runtime/helpers/possibleConstructorReturn";
import _getPrototypeOf from "@babel/runtime/helpers/getPrototypeOf";

function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }

function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {})); return true; } catch (e) { return false; } }

import * as React from 'react';
import classNames from 'classnames';

var Scratch = /*#__PURE__*/function (_React$PureComponent) {
  _inherits(Scratch, _React$PureComponent);

  var _super = _createSuper(Scratch);

  function Scratch(props) {
    var _this;

    _classCallCheck(this, Scratch);

    _this = _super.call(this, props);
    _this.state = {
      isAreaShow: true,
      isArea2Show: false
    };
    _this.touchStart = _this.touchStart.bind(_assertThisInitialized(_this));
    _this.touchMove = _this.touchMove.bind(_assertThisInitialized(_this));
    _this.touchEnd = _this.touchEnd.bind(_assertThisInitialized(_this));
    return _this;
  }

  _createClass(Scratch, [{
    key: "componentDidMount",
    value: function componentDidMount() {
      var wrap_canvas = document.getElementById('wrap_canvas');
      var icanvas = document.getElementById('myCanvas'); // if (wrap_canvas && icanvas) {

      var iwidth = wrap_canvas.clientWidth;
      var iheight = wrap_canvas.clientHeight;
      icanvas.width = iwidth;
      icanvas.height = iheight; // var drawMode = false;

      var context = icanvas.getContext('2d');
      context.lineCap = 'round';
      context.lineJoin = 'round'; // context.fillStyle = 'rgb(193,193,193)';
      // context.fillRect(0, 0, iwidth, iheight);

      var imgObj = new Image();
      imgObj.crossOrigin = 'Anonymous';
      imgObj.src = this.props.scratchImgUrl; //待图片加载完后，将其显示在canvas上

      imgObj.onload = function () {
        context.drawImage(imgObj, 0, 0, iwidth, iheight); //this即是imgObj,保持图片的原始大小：470*480
        //ctx.drawImage(this, 0, 0,1024,768); //改变图片的大小到1024*768
        // 在源图像外显示目标图像。只有源图像外的目标图像部分会被显示，源图像是透明的。(源图像：刮痕区域，目标图像：带图片的初始canvas)

        context.globalCompositeOperation = 'destination-out';
      }; // context.font = '24px 微软雅黑';
      // context.fillStyle = '#454444';
      // var txt = '刮这里';
      // context.fillText(txt, iwidth / 2 - context.measureText(txt).width / 2, iheight / 2 + 9);
      // context.globalCompositeOperation = 'destination-out';


      context.lineWidth = 30; // }
    }
  }, {
    key: "touchStart",
    value: function touchStart(e) {
      var icanvas = document.getElementById('myCanvas');
      var context = icanvas.getContext('2d');
      context.beginPath();
      var rect = icanvas.getBoundingClientRect();
      context.moveTo(e.changedTouches[0].clientX - rect.left, e.changedTouches[0].clientY - rect.top); // $("#area2").show();
    }
  }, {
    key: "touchMove",
    value: function touchMove(e) {
      // $icanvas.off('touchmove');
      e.persist();
      this.setState({
        isArea2Show: true
      }); // var e = event;

      var wrap_canvas = document.getElementById('wrap_canvas');
      var icanvas = document.getElementById('myCanvas');
      var context = icanvas.getContext('2d'); // if (this.state.down) {

      var rect = icanvas.getBoundingClientRect();
      context.lineTo(e.changedTouches[0].clientX - rect.left, e.changedTouches[0].clientY - rect.top);
      context.stroke(); // }

      var iwidth = wrap_canvas.clientWidth;
      var iheight = wrap_canvas.clientHeight;
      var imgData = context.getImageData(0, 0, iwidth, iheight),
          pixles = imgData.data,
          transPixs = [];

      for (var i = 0, j = pixles.length; i < j; i += 4) {
        var a = pixles[i + 3];

        if (a < 128) {
          //@ts-ignore
          transPixs.push(i);
        }
      } //@ts-ignore


      if (transPixs.length / (pixles.length / 4) * 100 > (this.props.resPercent >= 0 ? this.props.resPercent : 60)) {
        this.props.resCallback();
        this.setState({
          isAreaShow: false
        });
      }

      e.preventDefault && e.preventDefault();
      e.returnValue = false;
      e.stopPropagation && e.stopPropagation();
      return false;
    }
  }, {
    key: "touchEnd",
    value: function touchEnd() {// $icanvas.off('touchend');
      // this.setState({
      //   down: false,
      // });
    }
  }, {
    key: "render",
    value: function render() {
      var _this$props = this.props,
          prefixCls = _this$props.prefixCls,
          className = _this$props.className,
          style = _this$props.style;
      var cls = classNames(prefixCls, className);
      return /*#__PURE__*/React.createElement("div", {
        className: cls,
        style: style
      }, this.state.isAreaShow && /*#__PURE__*/React.createElement("div", {
        className: "area",
        id: "wrap_canvas"
      }, /*#__PURE__*/React.createElement("canvas", {
        id: "myCanvas",
        onTouchStart: this.touchStart,
        onTouchMove: this.touchMove,
        onTouchEnd: this.touchEnd
      })), this.state.isArea2Show && /*#__PURE__*/React.createElement("div", {
        className: "area2",
        id: "area2"
      }, this.props.children));
    }
  }]);

  return Scratch;
}(React.PureComponent);

export { Scratch as default };
Scratch.defaultProps = {
  prefixCls: 'Yep-scratch',
  style: {},
  scratchImgUrl: 'http://img12.360buyimg.com/uba/jfs/t20377/335/194083123/261/85331804/5b02899bN0571f2a7.png',
  resCallback: function resCallback() {}
};