For rotations, how to keep element centred on window resize?

[heldrida]

Hi,

Using GSAP TimelineMax for a 360 rotate loop animation; On window resize, I can't seem to keep the element centred;  I've got a live link here

If the page is refreshed, the instance when initialised at that point, has the element aligned properly. Only on window is resized, it breaks;

So, I've tried to use the method "kill()" and also setAttribute style and removed any css styles from there; create a new instance, but it breaks, making the animation super slow;

 

I wonder if there's a solution for this. Any tip is appreciated! Thanks!

See the Pen wGBBmm by helderoliveira (@helderoliveira) on CodePen

[ZachSaucier]

Since you're setting the width as a percent, you can avoid the issue by changing your CSS a bit. Instead of left: 50% and transforming it to center it, instead use left: 25%.

 

I also cleaned up your JS a bit in

See the Pen oxggPz?editors=0110 by Zeaklous (@Zeaklous) on CodePen

[Jonathan]

Hello heldrida. and Welcome to the GreenSock forum

 

To center your element, you dont need transforms to do this. You can just use regular CSS margin: 0 auto; and the element will stay in the center.

 

Remove your transform CSS property and add margin: 0 auto; to your img CSS rule.

 

See the Pen Wwbbgg by jonathan (@jonathan) on CodePen

 

/* no need to use transforms when you can use a simple margin with auto */
img {
    width: 50%;
    height: auto;
    display: block;
    position: relative;
    left:0;
    /*left: 50%;
    transform: translateX(-50%);
    -webkit-transform: translateX(-50%);*/

    margin: 0 auto; /* add margin auto to your img CSS rule */
  }

Also regarding the kill method.. what you can do is chain the seek() method to bring your timeline back to zero before using the kill() method

 

So you have this inside your resize event handler function callback:

tl.kill();

But add this to the return timeline to zero and then kill() timeline:

tl.seek(0).kill();

Resources:

CSS margin property: https://developer.mozilla.org/en-US/docs/Web/CSS/margin

GSAP seek() method: http://greensock.com/docs/#/HTML5/GSAP/TimelineMax/seek/

 

[heldrida]

Thanks guys!

So embarassing, I've failed testing this, I was sure centring margin 0 auto didn't work for some reason.

[Jonathan]

No worries heldrida

 

If you also had a transform and position offset left property on the same element with margin auto.. then it wont work since it would be overridden by the transform and position offset left properties.

 

Happy Tweening!