Javadoc
see http://api.jqueryui.com/focusable-selector/
No browser supports :focusable natively.
Some elements are natively focusable, while others require explicitly setting a tab index. In all cases, the element must be visible in order to be focusable.
Elements of the following type are focusable:
- input, if not disabled;
- select, if not disabled;
- textarea, if not disabled;
- button if not disabled;
- anchors, if they have an href or tabindex attribute.
- area elements are focusable if they are inside a named map, have an href attribute, and there is a visible image using the map.
- ALL OTHER elements are focusable based solely on their tabindex attribute and visibility.