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@njam
Created December 15, 2013 15:22
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(function($) {
function visible(element) {
return $.expr.filters.visible(element) && !$(element).parents().addBack().filter(function() {
return $.css(this, 'visibility') === 'hidden';
}).length;
}
function focusable(element, isTabIndexNotNaN) {
var map, mapName, img, nodeName = element.nodeName.toLowerCase();
if ('area' === nodeName) {
map = element.parentNode;
mapName = map.name;
if (!element.href || !mapName || map.nodeName.toLowerCase() !== 'map') {
return false;
}
img = $('img[usemap=#' + mapName + ']')[0];
return !!img && visible(img);
}
return (/input|select|textarea|button|object/.test(nodeName) ?
!element.disabled :
'a' === nodeName ?
element.href || isTabIndexNotNaN :
isTabIndexNotNaN) &&
// the element and all of its ancestors must be visible
visible(element);
}
$.extend($.expr[':'], {
focusable: function(element) {
return focusable(element, !isNaN($.attr(element, 'tabindex')));
}
});
})(jQuery);
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