overleaf/services/web/public/js/ace/undomanager.js

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2014-02-12 05:23:40 -05:00
/* ***** BEGIN LICENSE BLOCK *****
* Distributed under the BSD license:
*
* Copyright (c) 2010, Ajax.org B.V.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Ajax.org B.V. nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ***** END LICENSE BLOCK ***** */
define(function(require, exports, module) {
"use strict";
/**
*
*
* This object maintains the undo stack for an [[EditSession `EditSession`]].
* @class UndoManager
**/
/**
*
*
* Resets the current undo state and creates a new `UndoManager`.
*
* @constructor
**/
var UndoManager = function() {
this.reset();
};
(function() {
/**
* Provides a means for implementing your own undo manager. `options` has one property, `args`, an [[Array `Array`]], with two elements:
*
* - `args[0]` is an array of deltas
* - `args[1]` is the document to associate with
*
* @param {Object} options Contains additional properties
*
**/
this.execute = function(options) {
var deltas = options.args[0];
this.$doc = options.args[1];
if (options.merge && this.hasUndo()){
deltas = this.$undoStack.pop().concat(deltas);
}
this.$undoStack.push(deltas);
this.$redoStack = [];
if (this.dirtyCounter < 0) {
// The user has made a change after undoing past the last clean state.
// We can never get back to a clean state now until markClean() is called.
this.dirtyCounter = NaN;
}
this.dirtyCounter++;
};
/**
* [Perform an undo operation on the document, reverting the last change.]{: #UndoManager.undo}
* @param {Boolean} dontSelect {:dontSelect}
*
*
* @returns {Range} The range of the undo.
**/
this.undo = function(dontSelect) {
var deltas = this.$undoStack.pop();
var undoSelectionRange = null;
if (deltas) {
undoSelectionRange =
this.$doc.undoChanges(deltas, dontSelect);
this.$redoStack.push(deltas);
this.dirtyCounter--;
}
return undoSelectionRange;
};
/**
* [Perform a redo operation on the document, reimplementing the last change.]{: #UndoManager.redo}
* @param {Boolean} dontSelect {:dontSelect}
*
*
**/
this.redo = function(dontSelect) {
var deltas = this.$redoStack.pop();
var redoSelectionRange = null;
if (deltas) {
redoSelectionRange =
this.$doc.redoChanges(deltas, dontSelect);
this.$undoStack.push(deltas);
this.dirtyCounter++;
}
return redoSelectionRange;
};
/**
*
* Destroys the stack of undo and redo redo operations.
**/
this.reset = function() {
this.$undoStack = [];
this.$redoStack = [];
this.dirtyCounter = 0;
};
/**
*
* Returns `true` if there are undo operations left to perform.
* @returns {Boolean}
**/
this.hasUndo = function() {
return this.$undoStack.length > 0;
};
/**
*
* Returns `true` if there are redo operations left to perform.
* @returns {Boolean}
**/
this.hasRedo = function() {
return this.$redoStack.length > 0;
};
/**
*
* Marks the current status clean
**/
this.markClean = function() {
this.dirtyCounter = 0;
};
/**
*
* Returns if the current status is clean
* @returns {Boolean}
**/
this.isClean = function() {
return this.dirtyCounter === 0;
};
}).call(UndoManager.prototype);
exports.UndoManager = UndoManager;
});