-/**
- * Originally based of this code... - refactored for Roo...
- * https://github.com/aaalsaleh/undo-manager
-
- * undo-manager.js
- * @author Abdulrahman Alsaleh
- * @copyright 2015 Abdulrahman Alsaleh
- * @license MIT License (c)
- *
- * Hackily modifyed by alan@roojs.com
- *
- *
- * usage:
- * document.undoManager = new UndoManager(limit, document)
- *
- *
- * TOTALLY UNTESTED...
- *
- * Documentation to be done....
- */
-
-function UndoManager(limit, undoScopeHost) {
- var stack = [];
- var fireEvent = typeof CustomEvent != 'undefined' && undoScopeHost && undoScopeHost.dispatchEvent;
-
- this.position = 0;
- this.length = 0;
-
- this.transact = function (transaction, merge) {
- if (arguments.length < 2)
- throw new TypeError('Not enough arguments to UndoManager.transact.');
-
- transaction.execute();
-
- stack.splice(0, this.position);
- if (merge && this.length)
- stack[0].push(transaction);
- else
- stack.unshift([transaction]);
- this.position = 0;
-
- if (limit && stack.length > limit)
- this.length = stack.length = limit;
- else
- this.length = stack.length;
-
- if (fireEvent)
- undoScopeHost.dispatchEvent(new CustomEvent('DOMTransaction', {detail: {transactions: stack[0].slice()}, bubbles: true, cancelable: false}));
- };
-
- this.undo = function () {
- if (this.position < this.length) {
- for (var i = stack[this.position].length - 1; i >= 0; i--)
- stack[this.position][i].undo();
- this.position++;
-
- if (fireEvent)
- undoScopeHost.dispatchEvent(new CustomEvent('undo', {detail: {transactions: stack[this.position - 1].slice()}, bubbles: true, cancelable: false}));
- }
- };
-
- this.redo = function () {
- if (this.position > 0) {
- for (var i = 0, n = stack[this.position - 1].length; i < n; i++)
- stack[this.position - 1][i].redo();
- this.position--;
-
- if (fireEvent)
- undoScopeHost.dispatchEvent(new CustomEvent('redo', {detail: {transactions: stack[this.position].slice()}, bubbles: true, cancelable: false}));
- }
- };
-
- this.item = function (index) {
- if (index >= 0 && index < this.length)
- return stack[index].slice();
- return null;
- };
-
- this.clearUndo = function () {
- stack.length = this.length = this.position;
- };
-
- this.clearRedo = function () {
- stack.splice(0, this.position);
- this.position = 0;
- this.length = stack.length;
- };
- }
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