var ABSTRACT_WIDGET_INCLUDED = true;

// test to see that the AbstractSlider class is defined.
//alert("CONCRETE_ABSTRACTION_INCLUDED=" + CONCRETE_ABSTRACTION_INCLUDED);

if ( typeof CONCRETE_ABSTRACTION_INCLUDED == "undefined" )
{
	alert("Fatal Error: you need to include one of the concrete BrowserAbstraction subclasses before using the AbstractWidget class.");
}

if ( CONCRETE_ABSTRACTION_INCLUDED == false )
{
	alert("Fatal Error: you need to include one of the concrete BrowserAbstraction subclasses before using the AbstractWidget class.");
}

// GLOBALS (these are emulating static (aka class) variables for the AbstractWidget class)
var g_selectedWidget = null;
var g_widgetPath = "";

// CONSTANTS
var WIDGET_DIV_DELIMITER = "_";

function AbstractWidget(browserAbstractionLayer, instanceName)
{
	//this.id = id;
	this.browserAbstractionLayer = browserAbstractionLayer;
	this.instanceName = instanceName;

	// method declarations
	this.activate = activateMethod;
	this.deactivate = deactivateMethod;
	this.draw = drawMethod;
	this.readHtml = readHtmlMethod;
	this.setPosition = setPositionMethod;
	this.move = moveMethod;

	function setPositionMethod(x,y) 
	{
		throwUndefinedMethodException("setPosition");
	}

	function activateMethod(x,y) 
	{
		throwUndefinedMethodException("activate");
	}

	function deactivateMethod(x,y) 
	{
		// it's OK to do nothing here, the handler that called this method already does enough
	}

	function moveMethod(x,y) 
	{
		// it's OK to do nothing here, we just need a placeholder for Widgets that done catch move events
	}

	function drawMethod(x,y) 
	{
		// we do not want to make this required because we might have
		// the need to get the data from the page itself.
		// throwUndefinedMethodException("draw");
	}

	function readHtmlMethod() 
	{
		// we do not want to make this required because we might have
		// the need to get the data from the page itself.
		// throwUndefinedMethodException("draw");
	}
	
}

// static (class) methods
function setWidgetPath(relativePath)
{
	g_widgetPath = relativePath;
}

//Utility functions
function getInstanceNameFromDivID(htmlID)
{
	/*
	This function returns an instance of an AbstractWidget as long as the div id matches the pattern "instanceName_*"
	(assuming WIDGET_DIV_DELIMITER is set to "_")
	*/
	var objRef = null;
	if ( htmlID.indexOf(WIDGET_DIV_DELIMITER) != -1 )
	{
		var instanceName = htmlID.substr(0,htmlID.indexOf(WIDGET_DIV_DELIMITER));
		//alert("htmlID = " + htmlID + " instanceName " + instanceName)
		objRef = eval(instanceName);
		//objRef = eval(htmlID);
	}
	return objRef;
}

function throwUndefinedMethodException(methodName)
{
	alert("The method you have called, \"" + methodName + "\", has not been implemented.");
}