var Spry; if (!Spry) Spry = {}; if (!Spry.Utils) Spry.Utils = {};

Spry.Utils.Notifier = function()
{
	this.observers = [];
	this.suppressNotifications = 0;
};

Spry.Utils.Notifier.prototype.addObserver = function(observer)
{
	if (!observer)
		return;

	// Make sure the observer isn't already on the list.

	var len = this.observers.length;
	for (var i = 0; i < len; i++)
	{
		if (this.observers[i] == observer)
			return;
	}
	this.observers[len] = observer;
};

Spry.Utils.Notifier.prototype.removeObserver = function(observer)
{
	if (!observer)
		return;

	for (var i = 0; i < this.observers.length; i++)
	{
		if (this.observers[i] == observer)
		{
			this.observers.splice(i, 1);
			break;
		}
	}
};

Spry.Utils.Notifier.prototype.notifyObservers = function(methodName, data)
{
	if (!methodName)
		return;

	if (!this.suppressNotifications)
	{
		var len = this.observers.length;
		for (var i = 0; i < len; i++)
		{
			var obs = this.observers[i];
			if (obs)
			{
				if (typeof obs == "function")
					obs(methodName, this, data);
				else if (obs[methodName])
					obs[methodName](this, data);
			}
		}
	}
};

Spry.Utils.Notifier.prototype.enableNotifications = function()
{
	if (--this.suppressNotifications < 0)
	{
		this.suppressNotifications = 0;
		Spry.Debug.reportError("Unbalanced enableNotifications() call!\n");
	}
};

Spry.Utils.Notifier.prototype.disableNotifications = function()
{
	++this.suppressNotifications;
};