/*
 * FCKeditor - The text editor for internet
 * Copyright (C) 2003-2004 Frederico Caldeira Knabben
 * 
 * Licensed under the terms of the GNU Lesser General Public License:
 * http://www.opensource.org/licenses/lgpl-license.php
 * 
 * For further information visit:
 * http://www.fckeditor.net/
 * 
 * File Name: fckscriptloader.js
 * Defines the FCKScriptLoader object that is used to dynamically load
 * scripts in the editor.
 * 
 * Version:  2.0 RC3
 * Modified: 2004-05-31 23:07:50
 * 
 * File Authors:
 * Frederico Caldeira Knabben (fredck@fckeditor.net)
 */

// This object is used to download scripts and css files sequentialy.
// A file download is not started until the previous file was not completelly
// downloaded.
var FCKScriptLoader = new Object() ;
FCKScriptLoader.IsLoading = false ;
FCKScriptLoader.Queue = new Array() ;

// Adds a script or css to the queue.
FCKScriptLoader.AddScript = function( scriptPath )
{
FCKScriptLoader.Queue[ FCKScriptLoader.Queue.length ] = scriptPath ;

if ( !this.IsLoading )
this.CheckQueue() ;
}

// Checks the queue to see if there is something to load.
// This function should not be called by code. It's a internal function
// that's called recursively.
FCKScriptLoader.CheckQueue = function() 
{
// Check if the queue is not empty.
if ( this.Queue.length > 0 )
{
this.IsLoading = true ;

// Get the first item in the queue
var sScriptPath = this.Queue[0] ;

// Removes the first item from the queue
var oTempArray = new Array() ;
for ( i = 1 ; i < this.Queue.length ; i++ )
oTempArray[ i - 1 ] = this.Queue[ i ] ;
this.Queue = oTempArray ;

//window.status = ( 'Loading ' + sScriptPath + '...' ) ;

// Dynamically load the file (it can be a CSS or a JS)
var e ;

// If is a CSS
if ( sScriptPath.lastIndexOf( '.css' ) > 0 )
{
e = document.createElement( 'LINK' ) ;
e.rel= 'stylesheet' ;
e.type= 'text/css' ;
}
// It is a JS
else
{
e = document.createElement( "script" ) ;
e.type= "text/javascript" ;
}

// Add the new object to the HEAD.
document.getElementsByTagName("head")[0].appendChild( e ) ; 

var oEvent = function()
{
// Gecko doesn't have a "readyState" property
if ( this.tagName == 'LINK' || !this.readyState || this.readyState == 'loaded' )
// Load the next script available in the queue
FCKScriptLoader.CheckQueue() ;
}

// Start downloading it.
if ( e.tagName == 'LINK' )
{
// IE must wait for the file to be downloaded.
if ( FCKBrowserInfo.IsIE )
e.onload = oEvent ;
// Gecko doens't fire any event when the CSS is loaded, so we 
// can't wait for it.
else
FCKScriptLoader.CheckQueue() ;

e.href = sScriptPath ;
}
else
{
// Gecko fires the "onload" event and IE fires "onreadystatechange"
e.onload = e.onreadystatechange = oEvent ;
e.src = sScriptPath ;
}
}
else
{
this.IsLoading = false ;

// Call the "OnEmpty" event.
if ( this.OnEmpty ) 
this.OnEmpty() ;
}
}
