/** * @license Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved. * For licensing, see LICENSE.md. */ /** * @module undo/undocommand */ import BaseCommand from './basecommand'; import Batch from '@ckeditor/ckeditor5-engine/src/model/batch'; /** * The undo command stores {@link module:engine/model/batch~Batch batches} applied to the * {@link module:engine/model/document~Document document} and is able to undo a batch by reversing it and transforming by * batches from {@link module:engine/model/document~Document#history history} that happened after the reversed batch. * * The undo command also takes care of restoring the {@link module:engine/model/document~Document#selection document selection}. * * @extends module:undo/basecommand~BaseCommand */ export default class UndoCommand extends BaseCommand { /** * Executes the command. This method reverts a {@link module:engine/model/batch~Batch batch} added to the command's stack, transforms * and applies the reverted version on the {@link module:engine/model/document~Document document} and removes the batch from the stack. * Then, it restores the {@link module:engine/model/document~Document#selection document selection}. * * @fires execute * @fires revert * @param {module:engine/model/batch~Batch} [batch] A batch that should be undone. If not set, the last added batch will be undone. */ execute( batch = null ) { // If batch is not given, set `batchIndex` to the last index in command stack. const batchIndex = batch ? this._stack.findIndex( a => a.batch == batch ) : this._stack.length - 1; const item = this._stack.splice( batchIndex, 1 )[ 0 ]; const undoingBatch = new Batch(); // All changes has to be done in one `enqueueChange` callback so other listeners will not // step between consecutive operations, or won't do changes to the document before selection is properly restored. this.editor.model.enqueueChange( undoingBatch, () => { this._undo( item.batch, undoingBatch ); const operations = this.editor.model.document.history.getOperations( item.batch.baseVersion ); this._restoreSelection( item.selection.ranges, item.selection.isBackward, operations ); this.fire( 'revert', item.batch, undoingBatch ); } ); this.refresh(); } } /** * Fired when execution of the command reverts some batch. * * @event revert */