dojo.provide("dojo.a11y");
dojo.require("dojo.uri.*");
dojo.require("dojo.html.common");
dojo.a11y = {
// imgPath: String path to the test image for determining if images are displayed or not
// doAccessibleCheck: Boolean if true will perform check for need to create accessible widgets
// accessible: Boolean uninitialized when null (accessible check has not been performed)
// if true generate accessible widgets
imgPath:dojo.uri.dojoUri("src/widget/templates/images"),
doAccessibleCheck: true,
accessible: null,
checkAccessible: function(){
// summary:
// perform check for accessibility if accessibility checking is turned
// on and the accessibility test has not been performed yet
if(this.accessible === null){
this.accessible = false; //default
if(this.doAccessibleCheck == true){
this.accessible = this.testAccessible();
}
}
return this.accessible; /* Boolean */
},
testAccessible: function(){
// summary:
// Always perform the accessibility check to determine if high
// contrast mode is on or display of images are turned off. Currently only checks
// in IE and Mozilla.
this.accessible = false; //default
if (dojo.render.html.ie || dojo.render.html.mozilla){
var div = document.createElement("div");
//div.style.color="rgb(153,204,204)";
div.style.backgroundImage = "url(/doc/j/jc/jcap/Dojo/common/041/lib/src/quotquot__thisimgPath__quot/tab_close.gifquot)";
// must add to hierarchy before can view currentStyle below
dojo.body().appendChild(div);
// in FF and IE the value for the current background style of the added div
// will be "none" in high contrast mode
// in FF the return value will be url(/doc/j/jc/jcap/Dojo/common/041/lib/src/invalid_url/index.html) when running over http
var bkImg = null;
if (window.getComputedStyle ) {
var cStyle = getComputedStyle(div, "");
bkImg = cStyle.getPropertyValue("background-image");
}else{
bkImg = div.currentStyle.backgroundImage;
}
var bUseImgElem = false;
if (bkImg != null && (bkImg == "none" || bkImg == "url(/doc/j/jc/jcap/Dojo/common/041/lib/src/invalid_url/index.html)" )) {
this.accessible = true;
}
/*
if(this.accessible == false && document.images){
// test if images are off in IE
var testImg = new Image();
if(testImg.fileSize) {
testImg.src = this.imgPath + "/tab_close.gif";
if(testImg.fileSize < 0){
this.accessible = true;
}
}
}*/
dojo.body().removeChild(div);
}
return this.accessible; /* Boolean */
},
setCheckAccessible: function(/* Boolean */ bTest){
// summary:
// Set whether or not to check for accessibility mode. Default value
// of module is true - perform check for accessibility modes.
// bTest: Boolean - true to check; false to turn off checking
this.doAccessibleCheck = bTest;
},
setAccessibleMode: function(){
// summary:
// perform the accessibility check and sets the correct mode to load
// a11y widgets. Only runs if test for accessiiblity has not been performed yet.
// Call testAccessible() to force the test.
if (this.accessible === null){
if (this.checkAccessible()){
dojo.render.html.prefixes.unshift("a11y");
}
}
return this.accessible; /* Boolean */
}
};
//dojo.hostenv.modulesLoadedListeners.unshift(function() { dojo.a11y.setAccessibleMode(); });
//dojo.event.connect("before", dojo.hostenv, "makeWidgets", dojo.a11y, "setAccessibleMode");