Scriptaculous: How to make blind or slide smooth and not jump? Or is it not possible?

I was seeing a strange phenomena when using Scriptaculous BlindDown and SlideDown effects, where they would smoothly slide, and then at th开发者_Go百科e very end, they would jump an additional amount, maybe 10% of the slide distance.

I already saw the note on the BlindDown page that you have to be sure not to use padding, which I'd already done.

I was still thinking that this must be my mistake somehow, when I noticed that I see the exact same thing happening on their demo page for Toggle when clicking on either the Blind or Slide demos: http://wiki.github.com/madrobby/scriptaculous/effect-toggle

Firefox 3.6.7, Chrome 6, and Internet Explorer 8 all display this effect on my computer.

So I was thinking about just writing it off and either living with it or cutting the effect out, when I noticed that the page for BlindDown does not display this effect: http://wiki.github.com/madrobby/scriptaculous/effect-blinddown

So there must be a way to make this work. On my page, the jump is occurring whether I directly use BlindDown/Slide or whether I use Toggle.

Has anyone out there used these and managed to do so without this problem? Any ideas on what the secret is?

It's usually due to margin or padding. The element you're blind-downing mustn't have any margin or padding, or should have margin:0.1% so that contained margins don't collapse through the bounds of the element either. If you do this it'll be smooth as silk.

also - ensure you've set overflow:hidden

Enjoy.

(the other place it'll fall down is if you don't define height. If you do this little incantation before you animate it'll get and set you height without bothering anything else.

  elem.setStyle({position:'absolute',visiblity:'invisible'});
  elem.setStyle({'height':elem.getDimensions().height+'px'});
  elem.setStyle({position:'relative',visibility:'visible'}); //or position:'static'

In my experience, the jumping is just a performance issue, which is effected by the system specs, browser, and complexity of the html content you are toggling. Some browsers like safari and chrome have a pretty good javascript engine making them more efficient.

I see this is happening for you even when using chrome though? Is the html content particularly complex, or your computer overloaded with applications running?

There is definitely a little very well known secret... Have you tried wrapping your content in an extra div container? You should consider this best practice and almost a requirement specifically when using Scriptaculous effects.

For example... Say you want to slideDown or Toggle a login form - and you have::

<div id="login-panel">
   <input type="text" name="username" />
   <button type="submit" name="send">Login</button>
</div>

All you have to do is add an extra inner div tag::

<div id="login-panel">
<div><!-- extra div here -->
   <input type="text" name="username" />
   <button type="submit" name="send">Login</button>
</div><!-- close it here -->
</div>

Now when you do something like Effect.toggle("login-panel", 'slide'); the transition should be much smoother and less jumpy. It may seem a little sloppy but it almost always helps. Hope this helps you!!

Keep in mind that when Scriptaculous begins an animation, the container that is being modified will be absolutely positioned and then a record of the height will be taken, similar to what danielsherson mentions. If however the container does not exist within a relatively positioned parent container, then the dimensions of the animating container may change quite drastically. The easiest way to test this is to modify your container using firebug to set the position to absolute. What happens? Did the height change? For the best results, there should be no change in the dimensions of your animating container when switching to absolute positioning. What happens to the rest of your document, such as content moving underneath, will not matter.

The padding/margin issue is a tricky one too since there really isn't a way to prevent the margins from overlapping and creating issues. Best way I found to address this is to set your animating container to float and then use the clearfix hack on a parent container to make sure nothing overlaps.

<body style="margin: 0 auto; width: 300px; position: relative; background: black;">
  <div class="parent nonanimating clearfix">
    <div class="animating" style="float: left; width: 100%; background: white;">
      <div class="apply-your-margins-and-padding-here">
         ...content...
      </div>
    </div>
  </div>
  <div class="parent nonanimating clearfix">
    <div class="animating" style="float: left; width: 100%; background: white;">
      <div class="apply-your-margins-and-padding-here">
         ...content...
      </div>
    </div>
  </div>
</body>

Note that the classes are not functional and just for reference to my comments with the exception of clearfix, which is the float clear hack. The backgrounds and widths are only specified to give a better example of what is happening. Add whatever animation you'd like to $$('.animating')

I use this one (there are many), all though it is old and I don't even design for many of the browsers this hack supports..

.clearfix:after {
    content: ".";
    display: block;
    clear: both;
    visibility: hidden;
    height: 0;
}
.clearfix {
    display: inline-block;
}
/* Hides from IE-mac \*/
* html .clearfix {height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */

I don't think it's a performance issue at all. I'm having the same issue. The ONLY way I've been able to make it not jump is to define a height for the div I'm sliding. I realize that this is NOT a good solution but it's the only one I've been able to find. I've also tried adding the additional div and it had no effect on how the Effect.toggle slide worked.

If anyone else has any more info on this, I'm all ears.

To prevent a Scriptaculous effect from jumping or jerking, remove the 'style' attribute from the element which you are applying the Effect to.

This:

<div id="mydiv" style="padding:10px;margin:10px;">
  <button onClick="new Effect.BlindUp('mydiv');" />         
</div>

Becomes:

<div id="mydiv">
  <button onClick="new Effect.BlindUp('mydiv');" />         
</div>

The styling can be placed in a enclosed div like this:

<div id="mydiv">
  <div style="padding:10px;margin:10px;">
    <button onClick="new Effect.BlindUp('mydiv');" />
  </div>        
</div>

The problem is caused by Scriptaculous reapplying the element's (mydiv) inline style declarations after the effect has been performed.

I have found success with using position: relative; on the block element using the slide/blind animation. Make sure padding/margins are placed on the child elements and not the slide block element.