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

dijit.wai = {
	onload: function(){
		// summary:
		//		Detects if we are in high-contrast mode or not

		// This must be a named function and not an anonymous
		// function, so that the widget parsing code can make sure it
		// registers its onload function after this function.
		// DO NOT USE "this" within this function.

		// create div for testing if high contrast mode is on or images are turned off
		var div = dojo.doc.createElement("div");
		div.id = "a11yTestNode";
		div.style.cssText = 'border: 1px solid;'
			+ 'border-color:red green;'
			+ 'position: absolute;'
			+ 'height: 5px;'
			+ 'top: -999px;'
			+ 'background-image: url("' + dojo.moduleUrl("dojo", "resources/blank.gif") + '");';
		dojo.body().appendChild(div);

		// test it
		var cs = dojo.getComputedStyle(div);
		if(cs){
			var bkImg = cs.backgroundImage;
			var needsA11y = (cs.borderTopColor==cs.borderRightColor) || (bkImg != null && (bkImg == "none" || bkImg == "url(invalid-url:)" ));
			dojo[needsA11y ? "addClass" : "removeClass"](dojo.body(), "dijit_a11y");
			dojo.body().removeChild(div);
		}
	}
};

// Test if computer is in high contrast mode.
// Make sure the a11y test runs first, before widgets are instantiated.
if(dojo.isIE || dojo.isMoz){	// NOTE: checking in Safari messes things up
	dojo._loaders.unshift(dijit.wai.onload);
}

dojo.mixin(dijit,
{
	hasWaiRole: function(/*Element*/ elem){
		// summary: Determines if an element has a role.
		// returns: true if elem has a role attribute and false if not.
		return elem.hasAttribute ? elem.hasAttribute("role") : !!elem.getAttribute("role");
	},

	getWaiRole: function(/*Element*/ elem){
		// summary: Gets the role for an element.
		// returns:
		//		The role of elem or an empty string if elem
		//		does not have a role.
		var value = elem.getAttribute("role");
		if(value){
			var prefixEnd = value.indexOf(":");
			return prefixEnd == -1 ? value : value.substring(prefixEnd+1);
		}else{
			return "";
		}
	},

	setWaiRole: function(/*Element*/ elem, /*String*/ role){
		// summary: Sets the role on an element.
		// description:
		//		On Firefox 2 and below, "wairole:" is
		//		prepended to the provided role value.
		elem.setAttribute("role", (dojo.isFF && dojo.isFF < 3) ? "wairole:" + role : role);
	},

	removeWaiRole: function(/*Element*/ elem){
		// summary: Removes the role from an element.
		elem.removeAttribute("role");
	},

	hasWaiState: function(/*Element*/ elem, /*String*/ state){
		// summary: Determines if an element has a given state.
		// description:
		//		On Firefox 2 and below, we check for an attribute in namespace
		//		"http://www.w3.org/2005/07/aaa" with a name of the given state.
		//		On all other browsers, we check for an attribute
		//		called "aria-"+state.
		// returns:
		//		true if elem has a value for the given state and
		//		false if it does not.
		if(dojo.isFF && dojo.isFF < 3){
			return elem.hasAttributeNS("http://www.w3.org/2005/07/aaa", state);
		}else{
			return elem.hasAttribute ? elem.hasAttribute("aria-"+state) : !!elem.getAttribute("aria-"+state);
		}
	},

	getWaiState: function(/*Element*/ elem, /*String*/ state){
		// summary: Gets the value of a state on an element.
		// description:
		//		On Firefox 2 and below, we check for an attribute in namespace
		//		"http://www.w3.org/2005/07/aaa" with a name of the given state.
		//		On all other browsers, we check for an attribute called
		//		"aria-"+state.
		// returns:
		//		The value of the requested state on elem
		//		or an empty string if elem has no value for state.
		if(dojo.isFF && dojo.isFF < 3){
			return elem.getAttributeNS("http://www.w3.org/2005/07/aaa", state);
		}else{
			var value = elem.getAttribute("aria-"+state);
			return value ? value : "";
		}
	},

	setWaiState: function(/*Element*/ elem, /*String*/ state, /*String*/ value){
		// summary: Sets a state on an element.
		// description:
		//		On Firefox 2 and below, we set an attribute in namespace
		//		"http://www.w3.org/2005/07/aaa" with a name of the given state.
		//		On all other browsers, we set an attribute called
		//		"aria-"+state.
		if(dojo.isFF && dojo.isFF < 3){
			elem.setAttributeNS("http://www.w3.org/2005/07/aaa",
				"aaa:"+state, value);
		}else{
			elem.setAttribute("aria-"+state, value);
		}
	},

	removeWaiState: function(/*Element*/ elem, /*String*/ state){
		// summary: Removes a state from an element.
		// description:
		//		On Firefox 2 and below, we remove the attribute in namespace
		//		"http://www.w3.org/2005/07/aaa" with a name of the given state.
		//		On all other browsers, we remove the attribute called
		//		"aria-"+state.
		if(dojo.isFF && dojo.isFF < 3){
			elem.removeAttributeNS("http://www.w3.org/2005/07/aaa", state);
		}else{
			elem.removeAttribute("aria-"+state);
		}
	}
});

}
