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undocommand.js
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/
undocommand.js
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/**
* @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
*/
/**
* @module undo/undocommand
*/
import BaseCommand from './basecommand';
/**
* 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 = this.editor.model.createBatch( 'transparent' );
// 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
*/