slate-history/dist/slate-history.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('slate')) :
  typeof define === 'function' && define.amd ? define(['exports', 'slate'], factory) :
  (global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.SlateHistory = {}, global.Slate));
})(this, (function (exports, slate) { 'use strict';

  /*!
   * is-plain-object <https://github.com/jonschlinkert/is-plain-object>
   *
   * Copyright (c) 2014-2017, Jon Schlinkert.
   * Released under the MIT License.
   */

  function isObject(o) {
    return Object.prototype.toString.call(o) === '[object Object]';
  }

  function isPlainObject(o) {
    var ctor,prot;

    if (isObject(o) === false) return false;

    // If has modified constructor
    ctor = o.constructor;
    if (ctor === undefined) return true;

    // If has modified prototype
    prot = ctor.prototype;
    if (isObject(prot) === false) return false;

    // If constructor does not have an Object-specific method
    if (prot.hasOwnProperty('isPrototypeOf') === false) {
      return false;
    }

    // Most likely a plain Object
    return true;
  }

  // eslint-disable-next-line no-redeclare
  var History = {
    /**
     * Check if a value is a `History` object.
     */
    isHistory: function isHistory(value) {
      return isPlainObject(value) && Array.isArray(value.redos) && Array.isArray(value.undos) && (value.redos.length === 0 || slate.Operation.isOperationList(value.redos[0].operations)) && (value.undos.length === 0 || slate.Operation.isOperationList(value.undos[0].operations));
    }
  };

  /**
   * Weakmaps for attaching state to the editor.
   */
  var HISTORY = new WeakMap();
  var SAVING = new WeakMap();
  var MERGING = new WeakMap();
  // eslint-disable-next-line no-redeclare
  var HistoryEditor = {
    /**
     * Check if a value is a `HistoryEditor` object.
     */
    isHistoryEditor: function isHistoryEditor(value) {
      return History.isHistory(value.history) && slate.Editor.isEditor(value);
    },
    /**
     * Get the merge flag's current value.
     */
    isMerging: function isMerging(editor) {
      return MERGING.get(editor);
    },
    /**
     * Get the saving flag's current value.
     */
    isSaving: function isSaving(editor) {
      return SAVING.get(editor);
    },
    /**
     * Redo to the previous saved state.
     */
    redo: function redo(editor) {
      editor.redo();
    },
    /**
     * Undo to the previous saved state.
     */
    undo: function undo(editor) {
      editor.undo();
    },
    /**
     * Apply a series of changes inside a synchronous `fn`, without merging any of
     * the new operations into previous save point in the history.
     */
    withoutMerging: function withoutMerging(editor, fn) {
      var prev = HistoryEditor.isMerging(editor);
      MERGING.set(editor, false);
      fn();
      MERGING.set(editor, prev);
    },
    /**
     * Apply a series of changes inside a synchronous `fn`, without saving any of
     * their operations into the history.
     */
    withoutSaving: function withoutSaving(editor, fn) {
      var prev = HistoryEditor.isSaving(editor);
      SAVING.set(editor, false);
      fn();
      SAVING.set(editor, prev);
    }
  };

  function _createForOfIteratorHelper(o, allowArrayLike) { var it = typeof Symbol !== "undefined" && o[Symbol.iterator] || o["@@iterator"]; if (!it) { if (Array.isArray(o) || (it = _unsupportedIterableToArray(o)) || allowArrayLike && o && typeof o.length === "number") { if (it) o = it; var i = 0; var F = function F() {}; return { s: F, n: function n() { if (i >= o.length) return { done: true }; return { done: false, value: o[i++] }; }, e: function e(_e) { throw _e; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var normalCompletion = true, didErr = false, err; return { s: function s() { it = it.call(o); }, n: function n() { var step = it.next(); normalCompletion = step.done; return step; }, e: function e(_e2) { didErr = true; err = _e2; }, f: function f() { try { if (!normalCompletion && it["return"] != null) it["return"](); } finally { if (didErr) throw err; } } }; }
  function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }
  function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i]; return arr2; }
  /**
   * The `withHistory` plugin keeps track of the operation history of a Slate
   * editor as operations are applied to it, using undo and redo stacks.
   *
   * If you are using TypeScript, you must extend Slate's CustomTypes to use
   * this plugin.
   *
   * See https://docs.slatejs.org/concepts/11-typescript to learn how.
   */
  var withHistory = function withHistory(editor) {
    var e = editor;
    var apply = e.apply;
    e.history = {
      undos: [],
      redos: []
    };
    e.redo = function () {
      var history = e.history;
      var redos = history.redos;
      if (redos.length > 0) {
        var batch = redos[redos.length - 1];
        if (batch.selectionBefore) {
          slate.Transforms.setSelection(e, batch.selectionBefore);
        }
        HistoryEditor.withoutSaving(e, function () {
          slate.Editor.withoutNormalizing(e, function () {
            var _iterator = _createForOfIteratorHelper(batch.operations),
              _step;
            try {
              for (_iterator.s(); !(_step = _iterator.n()).done;) {
                var op = _step.value;
                e.apply(op);
              }
            } catch (err) {
              _iterator.e(err);
            } finally {
              _iterator.f();
            }
          });
        });
        history.redos.pop();
        e.writeHistory('undos', batch);
      }
    };
    e.undo = function () {
      var history = e.history;
      var undos = history.undos;
      if (undos.length > 0) {
        var batch = undos[undos.length - 1];
        HistoryEditor.withoutSaving(e, function () {
          slate.Editor.withoutNormalizing(e, function () {
            var inverseOps = batch.operations.map(slate.Operation.inverse).reverse();
            var _iterator2 = _createForOfIteratorHelper(inverseOps),
              _step2;
            try {
              for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
                var op = _step2.value;
                e.apply(op);
              }
            } catch (err) {
              _iterator2.e(err);
            } finally {
              _iterator2.f();
            }
            if (batch.selectionBefore) {
              slate.Transforms.setSelection(e, batch.selectionBefore);
            }
          });
        });
        e.writeHistory('redos', batch);
        history.undos.pop();
      }
    };
    e.apply = function (op) {
      var operations = e.operations,
        history = e.history;
      var undos = history.undos;
      var lastBatch = undos[undos.length - 1];
      var lastOp = lastBatch && lastBatch.operations[lastBatch.operations.length - 1];
      var save = HistoryEditor.isSaving(e);
      var merge = HistoryEditor.isMerging(e);
      if (save == null) {
        save = shouldSave(op);
      }
      if (save) {
        if (merge == null) {
          if (lastBatch == null) {
            merge = false;
          } else if (operations.length !== 0) {
            merge = true;
          } else {
            merge = shouldMerge(op, lastOp);
          }
        }
        if (lastBatch && merge) {
          lastBatch.operations.push(op);
        } else {
          var batch = {
            operations: [op],
            selectionBefore: e.selection
          };
          e.writeHistory('undos', batch);
        }
        while (undos.length > 100) {
          undos.shift();
        }
        history.redos = [];
      }
      apply(op);
    };
    e.writeHistory = function (stack, batch) {
      e.history[stack].push(batch);
    };
    return e;
  };
  /**
   * Check whether to merge an operation into the previous operation.
   */
  var shouldMerge = function shouldMerge(op, prev) {
    if (prev && op.type === 'insert_text' && prev.type === 'insert_text' && op.offset === prev.offset + prev.text.length && slate.Path.equals(op.path, prev.path)) {
      return true;
    }
    if (prev && op.type === 'remove_text' && prev.type === 'remove_text' && op.offset + op.text.length === prev.offset && slate.Path.equals(op.path, prev.path)) {
      return true;
    }
    return false;
  };
  /**
   * Check whether an operation needs to be saved to the history.
   */
  var shouldSave = function shouldSave(op, prev) {
    if (op.type === 'set_selection') {
      return false;
    }
    return true;
  };

  exports.HISTORY = HISTORY;
  exports.History = History;
  exports.HistoryEditor = HistoryEditor;
  exports.MERGING = MERGING;
  exports.SAVING = SAVING;
  exports.withHistory = withHistory;

}));