/**

 * @license Copyright (c) 2003-2013, CKSource - Frederico Knabben. All rights reserved.

 * For licensing, see LICENSE.md or http://ckeditor.com/license

 */



/**

 * @fileOverview Defines the {@link CKEDITOR.dom.text} class, which represents

 *		a DOM text node.

 */



/**

 * Represents a DOM text node.

 *

 *		var nativeNode = document.createTextNode( 'Example' );

 *		var text = CKEDITOR.dom.text( nativeNode );

 *

 *		var text = CKEDITOR.dom.text( 'Example' );

 *

 * @class

 * @extends CKEDITOR.dom.node

 * @constructor Creates a text class instance.

 * @param {Object/String} text A native DOM text node or a string containing

 * the text to use to create a new text node.

 * @param {CKEDITOR.dom.document} [ownerDocument] The document that will contain

 * the node in case of new node creation. Defaults to the current document.

 */

CKEDITOR.dom.text = function( text, ownerDocument ) {

	if ( typeof text == 'string' )

		text = ( ownerDocument ? ownerDocument.$ : document ).createTextNode( text );



	// Theoretically, we should call the base constructor here

	// (not CKEDITOR.dom.node though). But, IE doesn't support expando

	// properties on text node, so the features provided by domObject will not

	// work for text nodes (which is not a big issue for us).

	//

	// CKEDITOR.dom.domObject.call( this, element );



	this.$ = text;

};



CKEDITOR.dom.text.prototype = new CKEDITOR.dom.node();



CKEDITOR.tools.extend( CKEDITOR.dom.text.prototype, {

	/**

	 * The node type. This is a constant value set to {@link CKEDITOR#NODE_TEXT}.

	 *

	 * @readonly

	 * @property {Number} [=CKEDITOR.NODE_TEXT]

	 */

	type: CKEDITOR.NODE_TEXT,



	/**

	 * Gets length of node's value.

	 *

	 * @returns {Number}

	 */

	getLength: function() {

		return this.$.nodeValue.length;

	},



	/**

	 * Gets node's value.

	 *

	 * @returns {String}

	 */

	getText: function() {

		return this.$.nodeValue;

	},



	/**

	 * Sets node's value.

	 *

	 * @param {String} text

	 */

	setText: function( text ) {

		this.$.nodeValue = text;

	},



	/**

	 * Breaks this text node into two nodes at the specified offset,

	 * keeping both in the tree as siblings. This node then only contains

	 * all the content up to the offset point. A new text node, which is

	 * inserted as the next sibling of this node, contains all the content

	 * at and after the offset point. When the offset is equal to the

	 * length of this node, the new node has no data.

	 *

	 * @param {Number} The position at which to split, starting from zero.

	 * @returns {CKEDITOR.dom.text} The new text node.

	 */

	split: function( offset ) {



		// Saved the children count and text length beforehand.

		var parent = this.$.parentNode,

			count = parent.childNodes.length,

			length = this.getLength();



		var doc = this.getDocument();

		var retval = new CKEDITOR.dom.text( this.$.splitText( offset ), doc );



		if ( parent.childNodes.length == count )

		{

			// If the offset is after the last char, IE creates the text node

			// on split, but don't include it into the DOM. So, we have to do

			// that manually here.

			if ( offset >= length )

			{

				retval = doc.createText( '' );

				retval.insertAfter( this );

			}

			else

			{

				// IE BUG: IE8+ does not update the childNodes array in DOM after splitText(),

				// we need to make some DOM changes to make it update. (#3436)

				var workaround = doc.createText( '' );

				workaround.insertAfter( retval );

				workaround.remove();

			}

		}



		return retval;

	},



	/**

	 * Extracts characters from indexA up to but not including `indexB`.

	 *

	 * @param {Number} indexA An integer between `0` and one less than the

	 * length of the text.

	 * @param {Number} [indexB] An integer between `0` and the length of the

	 * string. If omitted, extracts characters to the end of the text.

	 */

	substring: function( indexA, indexB ) {

		// We need the following check due to a Firefox bug

		// https://bugzilla.mozilla.org/show_bug.cgi?id=458886

		if ( typeof indexB != 'number' )

			return this.$.nodeValue.substr( indexA );

		else

			return this.$.nodeValue.substring( indexA, indexB );

	}

});