Question

Just like http://twitter.github.com/bootstrap,

The site what I working on now is responsive.

I would like to remove transition animation

when I click the collapsed navbar menu button.

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Above picture is the screenshot of what I’m asking.

At TOP-RIGHT-CORNER, there is a three-lined menu button.

Answer 1

Bootstrap accomplishes the transition animation of the responsive nav bar the same way it does any collapse, which is using a CSS3 transition. To turn off the transition for only the navbar (leaving any other transitions in place), you simply have to override the CSS.

I’d suggest adding a class, such as no-transition (but the name can be arbitrary) to your collapsible container

<div class="nav-collapse no-transition">

and then defining a CSS rule that will disable the CSS3 transition that Bootstrap defined (make sure your CSS rule is parsed after bootstrap.css):

.no-transition {
  -webkit-transition: height 0;
  -moz-transition: height 0;
  -ms-transition: height 0;
  -o-transition: height 0;
  transition: height 0;
}

But, don’t stop there! Bootstrap’s JavaScript is hard-coded to assume that a transition WILL take place if transitions are supported by the browser. If you just make the change above, you’ll find that the collapsible object “locks” after one open/close cycle, because it is still waiting for the browser’s transition end event to fire. There are two less-than-ideal ways to work around this:

First option: hack bootstrap-collapse.js to not wait for the transition end event. Messing with Bootstrap is never a great idea because it’ll make future updates a pain for you. This particular work-around would also need to be similarly applied to any other Bootstrap JavaScript component onto which you wish to impart the no-transition class.

bootstrap-collapse.js:107

      this.$element.hasClass('no-transition') || (this.transitioning = 1);

Second, recommended, option: use an ultra-short transition time instead of disabling the transition. This doesn’t quite remove the transition animation as you asked, but it accomplishes a similar result with likely no noticable negative impact on the performance of your low-powered mobile devices. The upside of this method is that you don’t have to hack any Bootstrap JS files, and you can apply no-transition to any element, not just a collapse!

.no-transition {
  -webkit-transition: height 0.01s;
  -moz-transition: height 0.01s;
  -ms-transition: height 0.01s;
  -o-transition: height 0.01s;
  transition: height 0.01s;
}