/*
	Copyright (c) 2004-2008, The Dojo Foundation
	All Rights Reserved.

	Licensed under the Academic Free License version 2.1 or above OR the
	modified BSD license. For more information on Dojo licensing, see:

		http://dojotoolkit.org/book/dojo-book-0-9/introduction/licensing
*/


if(!dojo._hasResource["dijit._base.manager"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dijit._base.manager"] = true;
dojo.provide("dijit._base.manager");

dojo.declare("dijit.WidgetSet", null, {
	// summary:
	//	A set of widgets indexed by id

	constructor: function(){
		this._hash={};
	},

	add: function(/*Widget*/ widget){
		if(this._hash[widget.id]){
			throw new Error("Tried to register widget with id==" + widget.id + " but that id is already registered");
		}
		this._hash[widget.id]=widget;
	},

	remove: function(/*String*/ id){
		delete this._hash[id];
	},

	forEach: function(/*Function*/ func){
		for(var id in this._hash){
			func(this._hash[id]);
		}
	},

	filter: function(/*Function*/ filter){
		var res = new dijit.WidgetSet();
		this.forEach(function(widget){
			if(filter(widget)){ res.add(widget); }
		});
		return res;		// dijit.WidgetSet
	},

	byId: function(/*String*/ id){
		return this._hash[id];
	},

	byClass: function(/*String*/ cls){
		return this.filter(function(widget){ return widget.declaredClass==cls; });	// dijit.WidgetSet
	}
	});

/*=====
dijit.registry = {
	// summary: A list of widgets on a page.
	// description: Is an instance of dijit.WidgetSet
};
=====*/
dijit.registry = new dijit.WidgetSet();

dijit._widgetTypeCtr = {};

dijit.getUniqueId = function(/*String*/widgetType){
	// summary
	//	Generates a unique id for a given widgetType

	var id;
	do{
		id = widgetType + "_" +
			(widgetType in dijit._widgetTypeCtr ?
				++dijit._widgetTypeCtr[widgetType] : dijit._widgetTypeCtr[widgetType] = 0);
	}while(dijit.byId(id));
	return id; // String
};


if(dojo.isIE){
	// Only run this for IE because we think it's only necessary in that case,
	// and because it causes problems on FF.  See bug #3531 for details.
	dojo.addOnUnload(function(){
		dijit.registry.forEach(function(widget){ widget.destroy(); });
	});
}

dijit.byId = function(/*String|Widget*/id){
	// summary:
	//		Returns a widget by its id, or if passed a widget, no-op (like dojo.byId())
	return (dojo.isString(id)) ? dijit.registry.byId(id) : id; // Widget
};

dijit.byNode = function(/* DOMNode */ node){
	// summary:
	//		Returns the widget as referenced by node
	return dijit.registry.byId(node.getAttribute("widgetId")); // Widget
};

dijit.getEnclosingWidget = function(/* DOMNode */ node){
	// summary:
	//		Returns the widget whose dom tree contains node or null if
	//		the node is not contained within the dom tree of any widget
	while(node){
		if(node.getAttribute && node.getAttribute("widgetId")){
			return dijit.registry.byId(node.getAttribute("widgetId"));
		}
		node = node.parentNode;
	}
	return null;
};

// elements that are tab-navigable if they have no tabindex value set
// (except for "a", which must have an href attribute)
dijit._tabElements = {
	area: true,
	button: true,
	input: true,
	object: true,
	select: true,
	textarea: true
};

dijit._isElementShown = function(/*Element*/elem){
	var style = dojo.style(elem);
	return (style.visibility != "hidden")
		&& (style.visibility != "collapsed")
		&& (style.display != "none");
}

dijit.isTabNavigable = function(/*Element*/elem){
	// summary:
	//		Tests if an element is tab-navigable
	if(dojo.hasAttr(elem, "disabled")){ return false; }
	var hasTabindex = dojo.hasAttr(elem, "tabindex");
	var tabindex = dojo.attr(elem, "tabindex");
	if(hasTabindex && tabindex >= 0) {
		return true; // boolean
	}
	var name = elem.nodeName.toLowerCase();
	if(((name == "a" && dojo.hasAttr(elem, "href"))
			|| dijit._tabElements[name])
		&& (!hasTabindex || tabindex >= 0)){
		return true; // boolean
	}
	return false; // boolean
};

dijit._getTabNavigable = function(/*DOMNode*/root){
	// summary:
	//		Finds the following descendants of the specified root node:
	//		* the first tab-navigable element in document order
	//		  without a tabindex or with tabindex="0"
	//		* the last tab-navigable element in document order
	//		  without a tabindex or with tabindex="0"
	//		* the first element in document order with the lowest
	//		  positive tabindex value
	//		* the last element in document order with the highest
	//		  positive tabindex value
	var first, last, lowest, lowestTabindex, highest, highestTabindex;
	var walkTree = function(/*DOMNode*/parent){
		dojo.query("> *", parent).forEach(function(child){
			var isShown = dijit._isElementShown(child);
			if(isShown && dijit.isTabNavigable(child)){
				var tabindex = dojo.attr(child, "tabindex");
				if(!dojo.hasAttr(child, "tabindex") || tabindex == 0){
					if(!first){ first = child; }
					last = child;
				}else if(tabindex > 0){
					if(!lowest || tabindex < lowestTabindex){
						lowestTabindex = tabindex;
						lowest = child;
					}
					if(!highest || tabindex >= highestTabindex){
						highestTabindex = tabindex;
						highest = child;
					}
				}
			}
			if(isShown){ walkTree(child) }
		});
	};
	if(dijit._isElementShown(root)){ walkTree(root) }
	return { first: first, last: last, lowest: lowest, highest: highest };
}

dijit.getFirstInTabbingOrder = function(/*String|DOMNode*/root){
	// summary:
	//		Finds the descendant of the specified root node
	//		that is first in the tabbing order
	var elems = dijit._getTabNavigable(dojo.byId(root));
	return elems.lowest ? elems.lowest : elems.first; // Element
};

dijit.getLastInTabbingOrder = function(/*String|DOMNode*/root){
	// summary:
	//		Finds the descendant of the specified root node
	//		that is last in the tabbing order
	var elems = dijit._getTabNavigable(dojo.byId(root));
	return elems.last ? elems.last : elems.highest; // Element
};

}
