12

Given the sample markup:

<div>
    <input />
    <input />
    <input />
</div>

How can one, via jQuery, determine that div has lost focus?

I can use focusout() but that's not quite what I need. With focusout, it will get triggered as one tabs from input to input, as it's actually detecting (via event bubbling) that the input is losing focus.

Another way to word the requirement: I need to know when focus has moved OUTSIDE of the div.

I asked a similar question before:

jquery focusin() and preventing bubbling

But that was related to a pop-up UI and one can get around that by inserting a blank DIV behind it and putting a click/focus event on that as a trigger but that's won't work for this situation.

The next thought I had was to test for focusin when calling focusout:

    $(".myobject").focusout(function(element) {
    if(!($(this).focusin())){
        console.log('doYourThing ' + $(this));
    }
});

Alas, that doesn't work (I'm guessing due to the fact that it's evaluating focusin during the focusout event and, as such, it hasn't detected focusin yet.

Any clever solutions to this problem? Am I maybe missing a native jQuery event that does exactly what I'm looking for?

UPDATE:

Actually, the simplified question:

I need the equivalent of $('div').blur() but that would actually work on a div (since blur can't be triggered from a div)

4

3 回答 3

19

Taking Pointy's answer and going a little further with it.

creating a (simple) focuslost event plugin

(function($) {
    // will store the last focus chain
    var currentFocusChain = $();
    // stores a reference to any DOM objects we want to watch focus for
    var focusWatch = [];

    function checkFocus() {
        var newFocusChain = $(":focus").parents().andSelf();
        // elements in the old focus chain that aren't in the new focus chain...
        var lostFocus = currentFocusChain.not(newFocusChain.get());
        lostFocus.each(function() {
            if ($.inArray(this, focusWatch) != -1) {
                $(this).trigger('focuslost');
            }
        });
        currentFocusChain = newFocusChain;
    }
    // bind to the focus/blur event on all elements:
    $("*").live('focus blur', function(e) { 
        // wait until the next free loop to process focus change
        // when 'blur' is fired, focus will be unset
        setTimeout(checkFocus, 0);
    });

    $.fn.focuslost = function(fn) {
        return this.each(function() {
            // tell the live handler we are watching this event
            if ($.inArray(this, focusWatch) == -1) focusWatch.push(this);
            $(this).bind('focuslost', fn);
        });
    };
})(jQuery);

Example Use

$("div").focuslost(function() {
  $(this).append("<div>Lost Focus!</div>");
});

jsfiddle demo

于 2010-06-21T22:49:47.843 回答
5

Another plugin to look at is Ben Alman's Outside Events plugin. It allows you to detect when any of the following events are triggered on anything outside of a specific element and its children: clickoutside, dblclickoutside, focusoutside, bluroutside, mousemoveoutside, mousedownoutside, mouseupoutside, mouseoveroutside, mouseoutoutside, keydownoutside, keypressoutside, keyupoutside, changeoutside, selectoutside, submitoutside.

于 2010-06-22T18:16:31.870 回答
4

Well, what might work would be to bind a "focus" handler to everything, and you know when you're not in the <div> when you get a "focus" event elsewhere.

$('body').live('focus', (function() {
  var inDiv = false;
  return function(e) {
    if ($(this).closest('#theDiv').length)
      inDiv = true;
    else {
      if (inDiv)
        alert("just lost focus!");
      inDiv = false;
    }
  };
 });
于 2010-06-21T22:07:41.000 回答