@20minutes/draft-convert/lib/util/updateMutation.js

Extensibly serialize & deserialize Draft.js ContentState

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = updateMutation;
var _defineProperty2 = _interopRequireDefault(require("@babel/runtime/helpers/defineProperty"));
function ownKeys(e, r) { var t = Object.keys(e); if (Object.getOwnPropertySymbols) { var o = Object.getOwnPropertySymbols(e); r && (o = o.filter(function (r) { return Object.getOwnPropertyDescriptor(e, r).enumerable; })), t.push.apply(t, o); } return t; }
function _objectSpread(e) { for (var r = 1; r < arguments.length; r++) { var t = null != arguments[r] ? arguments[r] : {}; r % 2 ? ownKeys(Object(t), !0).forEach(function (r) { (0, _defineProperty2["default"])(e, r, t[r]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) { Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r)); }); } return e; }
function updateMutation(mutation, originalOffset, originalLength, newLength, prefixLength, suffixLength) {
  // three cases we can reasonably adjust - disjoint mutations that
  // happen later on where the offset will need to be changed,
  // mutations that completely contain the new one where we can adjust
  // the length, and mutations that occur partially within the new one.
  var lengthDiff = newLength - originalLength;
  var mutationAfterChange = originalOffset + originalLength <= mutation.offset;
  if (mutationAfterChange) {
    return _objectSpread(_objectSpread({}, mutation), {}, {
      offset: mutation.offset + lengthDiff
    });
  }
  var mutationContainsChange = originalOffset >= mutation.offset && originalOffset + originalLength <= mutation.offset + mutation.length;
  if (mutationContainsChange) {
    return _objectSpread(_objectSpread({}, mutation), {}, {
      length: mutation.length + lengthDiff
    });
  }
  var mutationWithinPrefixChange = mutation.offset >= originalOffset && mutation.offset + mutation.length <= originalOffset + originalLength && prefixLength > 0;
  if (mutationWithinPrefixChange) {
    return _objectSpread(_objectSpread({}, mutation), {}, {
      offset: mutation.offset + prefixLength
    });
  }
  var mutationContainsPrefix = mutation.offset < originalOffset && mutation.offset + mutation.length <= originalOffset + originalLength && mutation.offset + mutation.length > originalOffset && prefixLength > 0;
  if (mutationContainsPrefix) {
    return [_objectSpread(_objectSpread({}, mutation), {}, {
      length: originalOffset - mutation.offset
    }), _objectSpread(_objectSpread({}, mutation), {}, {
      offset: originalOffset + prefixLength,
      length: mutation.offset - originalOffset + mutation.length
    })];
  }
  var mutationContainsSuffix = mutation.offset >= originalOffset && mutation.offset + mutation.length > originalOffset + originalLength && originalOffset + originalLength > mutation.offset && suffixLength > 0;
  if (mutationContainsSuffix) {
    return [_objectSpread(_objectSpread({}, mutation), {}, {
      offset: mutation.offset + prefixLength,
      length: originalOffset + originalLength - mutation.offset
    }), _objectSpread(_objectSpread({}, mutation), {}, {
      offset: originalOffset + originalLength + prefixLength + suffixLength,
      length: mutation.offset + mutation.length - (originalOffset + originalLength)
    })];
  }
  return mutation;
}