CODEWITHSUNDEEP
javascriptipadcsscordova
Daniel
Daniel

Reputation: 890

iPad css3 animation flickers after keyboard use

I'm developing an app for the iPad using HTML5/CSS3. I'm not using any framework and am just using whatever is natively supported on the device. I have created some css3 animations to emulate the typical iOS sliding left or sliding right when navigating between screens. Here's an example of the slide left animation which is taking advantage of the iPad's CSS3 hardware acceleration: (the ipad is running 4.2).

/*************************************************
Slide Left
*************************************************/
.screen.slideleft{
 -webkit-animation-duration: 0.5s;
 -webkit-animation-timing-function: ease-in-out;
}
.screen.slideleft.outgoing{
 z-index: 50 !important;
 -webkit-animation-name: slideleft-outgoing;

}
.screen.slideleft.incoming{
 z-index: 100 !important;
 -webkit-animation-name: slideleft-incoming;
}
@-webkit-keyframes slideleft-outgoing{
 from { -webkit-transform: translate3d(0%,0,0); }
 to { -webkit-transform: translate3d(-100%,0,0); }
}
@-webkit-keyframes slideleft-incoming{
 from { -webkit-transform: translate3d(100%,0,0); }
 to { -webkit-transform: translate3d(0%,0,0); }
}

I also have this CSS which I've attempted to use to fix the flicker: 

.incoming,
.outgoing{
 display: block !important;
 -webkit-backface-visibility: hidden;
}

This works great until the iPad keyboard is used. After which point all the animations flicker severely.

I've been looking for examples of an iPad HTML5 app that uses the keyboard and doesn't have flickers afterwards, but haven't turned up much. The jqTouch demos exhibit the same behavior on the iPad (although I know they were designed for the iPhone).

I've turned up a few posts/questions of similar questions but have never found a good answer. I've been through http://css3animator.com/2010/12/fight-the-flicker-making-your-css3-animation-bomb-proof/ and the articles linked there but haven't had any success.

Any other suggestions?

Update 1/13 @ 9am

I've added this css and it helped a lot: 

.incoming *,
.outgoing *{
 -webkit-backface-visibility: hidden;
 -webkit-transform: translate3d(0,0,0); /* This helps with the flicker a lot. */
}

The foreground elements don't seem to flicker anymore, but the backgrounds still do. Still looking for some help or helpful resources on Mobile Safari's memory handling tactics.

Update 1/16 @ 11pm

Increasing the z-index as suggested by anonymous. Didn't seem to make a difference.

Update 1/17 @ 8:30am

I've posted a demo of the problem here.

The transitions between screens work great...until you tap/click inside one of the form fields. After the keyboard slides up and returns, all the transitions flicker. Go to the URL inside the iOS simulator or on an actual iPad to see what I'm talking about.

Upvotes: 17

Views: 7154

Answers (8)

Eric
Eric

Reputation: 159

This is an old question, but I thought I'd share my experience.

I've been having issues with outrageous flickering (on css3 animations) on the iPad (as well as the iPhone, but in that case only in portrait view). I was able to completely resolve all of the flickering issues by setting :

-webkit-perspective: 0;

On the elements being animated. I'm not sure why this works, but it does (tested on iOS 4.2+, both iPad (1 and 2) and iPhone 4).

Update: I've just become aware of an issue with Chrome when setting the value of that attribute to 1. It works just fine when it's 0, so I've updated the above appropriately.

Upvotes: 4

Pantelis
Pantelis

Reputation: 6146

I know this is a dinosaur old question, but there is a solution for this issue and it is quite lightweight and very simple.

document.getElementById('clicked_input').addEventListener('focus', function(e){
    e.stopPropagation();
},false);

When i was tackling this issue too, I thought I tried everything - eventually the only thing that helped, was to create a modal window (position: absolute) outside of the app's container div, and also set the app's container div to display:false; when the keyboard was coming up. While it worked it was ugly, I tested everything to see what caused the event and it seemed that when the 'focus event' bubbled up, every 3d transform gets messed up (in flickering and performance).

Preventing the event of bubbling solved this issue completely - quite mind boggling that such a hated bug had such a simple solution?

Upvotes: 1

KevChapman
KevChapman

Reputation: 11

I've recently been having the same problem and tried all sorts of complicated fixes. In the end I found the issue was down to the default styling on the input. I fixed my problem by adding the css input{outline:none}. It's prob just on the focus state so input:focus{outline:none;} should work.

Upvotes: 0

Daniel
Daniel

Reputation: 890

Ultimately, there really wasn't a fix for this issue. It seems like form elements in WebKit on the iPad cause problems with flickering.

My workaround was that on the onblur of each form element, I refreshed the page using hash tags to ensure it refreshed to the exact same state. It still caused a "flicker" while it was refreshing, but it did keep the screen from flickering throughout the rest of the app.

Upvotes: 0

Daniel Kurka
Daniel Kurka

Reputation: 7985

I had the same issue, but i was able to reduce the flicker to almost unnoticeable by applying the fix described here and here:

http://code.google.com/p/jqtouch/issues/detail?id=301

https://github.com/senchalabs/jQTouch/issues/issue/130

Basically set the z-index of the page you a are moving out to -1 and after the transistion back to 1

Upvotes: 1

Ian Storm Taylor
Ian Storm Taylor

Reputation: 8710

I agree with Ben, you should probably set transforms on the classes themselves as well:

/*************************************************
Slide Left
*************************************************/
.screen.slideleft{
 -webkit-animation-duration: 0.5s;
 -webkit-animation-timing-function: ease-in-out;
 -webkit-transform: translate3d(0,0,0);
}
.screen.slideleft.outgoing{
 z-index: 50 !important;
 -webkit-animation-name: slideleft-outgoing;
 -webkit-transform: translate3d(-100%,0,0);
}
.screen.slideleft.incoming{
 z-index: 100 !important;
 -webkit-animation-name: slideleft-incoming;
 -webkit-transform: translate3d(0,0,0);
}
@-webkit-keyframes slideleft-outgoing{
 from { -webkit-transform: translate3d(0,0,0); }
 to { -webkit-transform: translate3d(-100%,0,0); }
}
@-webkit-keyframes slideleft-incoming{
 from { -webkit-transform: translate3d(100%,0,0); }
 to { -webkit-transform: translate3d(0,0,0); }
}

If that doesn't work, I'd be curious to test if only translating the X with translateX(-100%) fixes the problem. (Not necessarily a fix, because you don't have hardware acceleration without 3D transforms, but would help narrow down the problem.)

Upvotes: 0

Ben Collier
Ben Collier

Reputation: 618

Looking at your source, the translate3d(0,0,0) isn't applied until the transition starts?

Try

.screen{
    -webkit-transform: translate3d(0,0,0);
}

or

.screen *, .screen{
        -webkit-transform: translate3d(0,0,0);
}

The flicker is probably the hardware acceleration kicking in (it currently only works on 3d translated elements).

Upvotes: 1

Anonymous
Anonymous

Reputation:

You're not going to like me saying this, but JavaScript may be the answer you're looking for. I fear that when you bring the keyboard up, the process of rendering the HTML loses priority. With a continually updating script, like a setInterval loop, the iPad will have no choice but to render as planned. Explicit code requires no hacks.

Upvotes: 0

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