CSS3 transition events

问题:

Are there any events fired by an element to check wether a css3 transition has started or end?

回答1:

W3C CSS Transitions Draft

The completion of a CSS Transition generates a corresponding DOM Event. An event is fired for each property that undergoes a transition. This allows a content developer to perform actions that synchronize with the completion of a transition.

---

Webkit

You can set a handler for a DOM event that is sent at the end of a transition. The event is an instance of WebKitTransitionEvent and its type is webKitTransitionEnd in JavaScript.

box.addEventListener( \'webkitTransitionEnd\', 
    function( event ) { alert( \"Finished transition!\" ); }, false );

Mozilla

There is a single event that is fired when transitions complete. In Firefox, the event is transitionend, in Opera, oTransitionEnd, and in WebKit it is webkitTransitionEnd.

Opera

There is one type of transition event available. The oTransitionEnd event occurs at the completion of the transition.

Internet Explorer

The transitionend event occurs at the completion of the transition. If the transition is removed before completion, the event will not fire.

---

SO: How do I normalize CSS3 Transition functions across browsers?

回答2:

I was using the approach given by Pete, however I have now started using the following

$(\".myClass\").one(\'transitionend webkitTransitionEnd oTransitionEnd otransitionend MSTransitionEnd\', 
function() {
 //do something
});

---

Alternatively if you use bootstrap then you can simply do

$(\".myClass\").one($.support.transition.end,
function() {
 //do something
});

This is becuase they include the following in bootstrap.js

+function ($) {
  \'use strict\';

  // CSS TRANSITION SUPPORT (Shoutout: http://www.modernizr.com/)
  // ============================================================

  function transitionEnd() {
    var el = document.createElement(\'bootstrap\')

    var transEndEventNames = {
      \'WebkitTransition\' : \'webkitTransitionEnd\',
      \'MozTransition\'    : \'transitionend\',
      \'OTransition\'      : \'oTransitionEnd otransitionend\',
      \'transition\'       : \'transitionend\'
    }

    for (var name in transEndEventNames) {
      if (el.style[name] !== undefined) {
        return { end: transEndEventNames[name] }
      }
    }

    return false // explicit for ie8 (  ._.)
  }


  $(function () {
    $.support.transition = transitionEnd()
  })

}(jQuery);

Note they also include an emulateTransitionEnd function which may be needed to ensure a callback always occurs.

  // http://blog.alexmaccaw.com/css-transitions
  $.fn.emulateTransitionEnd = function (duration) {
    var called = false, $el = this
    $(this).one($.support.transition.end, function () { called = true })
    var callback = function () { if (!called) $($el).trigger($.support.transition.end) }
    setTimeout(callback, duration)
    return this
  }

Be aware that sometimes this event doesn’t fire, usually in the case when properties don’t change or a paint isn’t triggered. To ensure we always get a callback, let’s set a timeout that’ll trigger the event manually.

http://blog.alexmaccaw.com/css-transitions

回答3:

All modern browsers now support the unprefixed event:

element.addEventListener(\'transitionend\', callback, false);

Works in the latest versions of Chrome, Firefox and Safari. Even IE10+.

回答4:

In Opera 12 when you bind using the plain JavaScript, \'oTransitionEnd\' will work:

document.addEventListener(\"oTransitionEnd\", function(){
    alert(\"Transition Ended\");
});

however if you bind through jQuery, you need to use \'otransitionend\'

$(document).bind(\"otransitionend\", function(){
    alert(\"Transition Ended\");
});

In case you are using Modernizr or bootstrap-transition.js you can simply do a change:

var transEndEventNames = {
    \'WebkitTransition\' : \'webkitTransitionEnd\',
    \'MozTransition\'    : \'transitionend\',
    \'OTransition\'      : \'oTransitionEnd otransitionend\',
    \'msTransition\'     : \'MSTransitionEnd\',
    \'transition\'       : \'transitionend\'
},
transEndEventName = transEndEventNames[ Modernizr.prefixed(\'transition\') ];

You can find some info here as well http://www.ianlunn.co.uk/blog/articles/opera-12-otransitionend-bugs-and-workarounds/

回答5:

Just for fun, don\'t do this!

$.fn.transitiondone = function () {
  return this.each(function () {
    var $this = $(this);
    setTimeout(function () {
      $this.trigger(\'transitiondone\');
    }, (parseFloat($this.css(\'transitionDelay\')) + parseFloat($this.css(\'transitionDuration\'))) * 1000);
  });
};


$(\'div\').on(\'mousedown\', function (e) {
  $(this).addClass(\'bounce\').transitiondone();
});

$(\'div\').on(\'transitiondone\', function () {
  $(this).removeClass(\'bounce\');
});

回答6:

If you simply want to detect only a single transition end, without using any JS framework here\'s a little convenient utility function:

function once = function(object,event,callback){
    var handle={};

    var eventNames=event.split(\" \");

    var cbWrapper=function(){
        eventNames.forEach(function(e){
            object.removeEventListener(e,cbWrapper, false );
        });
        callback.apply(this,arguments);
    };

    eventNames.forEach(function(e){
        object.addEventListener(e,cbWrapper,false);
    });

    handle.cancel=function(){
        eventNames.forEach(function(e){
            object.removeEventListener(e,cbWrapper, false );
        });
    };

    return handle;
};

Usage:

var handler = once(document.querySelector(\'#myElement\'), \'transitionend\', function(){
   //do something
});

then if you wish to cancel at some point you can still do it with

handler.cancel();

It\'s good for other event usages as well :)