how to call foo only if click OR focus fired

One more version of debounce function implementation:

link: function($scope, $element, $attrs) {

    var callOnce = (function() {
        var timeout;
        return function(e, callback) {
            clearTimeout(timeout);
            timeout = setTimeout(function() {
                callback.call(self, e);
            }.bind(this), 200); 
        };
    })();

    $element.bind('click focus mouseover', function(e) {
        callOnce.call(this, e, foo);
    });
}

Demo: http://plnkr.co/edit/HjwedaqUcGj6KncpDtwJ?p=preview

You can debounce the events, that would only fire the function for the first event

$element.bind('click focus', function(e) {
    if ( !$(this).data('fired') ) foo(e);

    $(this).data('fired', true);

    setTimeout(function(self) {
        $(self).data('fired', false);
    }, 200, this);

});

FIDDLE