/*
 * FCKeditor - The text editor for internet
 * Copyright (C) 2003-2005 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.
 * 
 * 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 ;
		
		this.LoadFile( sScriptPath ) ;
	}
	else
	{
		this.IsLoading = false ;
		
		// Call the "OnEmpty" event.
		if ( this.OnEmpty ) 
			this.OnEmpty() ;
	}
}

if ( FCKBrowserInfo.IsSafari )
{
	FCKScriptLoader.LoadFile = function( filePath ) 
	{
		if ( filePath.lastIndexOf( '.css' ) > 0 )
		{
			this.CheckQueue() ;
			return ;
		}
		
		var oXmlRequest = new XMLHttpRequest() ;
		
		// Load the script synchronously.
		oXmlRequest.open( "GET", filePath, false ) ;
		oXmlRequest.send( null ) ;
		
		// Evaluate the script.
		if ( oXmlRequest.status == 200 )
		{
			try
			{
				eval( oXmlRequest.responseText ) ;
			}
			catch ( e )
			{
				alert( 'Error parsing ' + filePath + ': ' + e.message ) ;
			}
		}
		else
			alert( 'Error loading ' + filePath ) ;
			
		this.CheckQueue() ;
	}
}
else
{
	FCKScriptLoader.LoadFile = function( filePath ) 
	{
		//window.status = ( 'Loading ' + filePath + '...' ) ;

		// Dynamically load the file (it can be a CSS or a JS)
		var e ;
		
		// If is a CSS
		if ( filePath.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 ) ; 

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

	function FCKScriptLoader_OnLoad()
	{
		// 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() ;
	}
}