Scrollsmoother with lazysizes/lazyload images

[Superloop]

Hi!

I'm trying to use Scrollsmoother but I have a problem with lazyload images.

The scroll doesn't refresh or update when images are loaded.

Maybe it could nice a method for refresh or update scrollsmoother.

Anyone has a solution for this?

Thanks!

See the Pen OJzQgRQ by marctaule (@marctaule) on CodePen.

[walpolea]

I ran into the same issue with a tabbed component changing the content height. The only solution I found was to dispatch a resize event which ScrollTrigger refreshes values on pretty gracefully.

window.dispatchEvent(new Event("resize"));

 

This also works as images lazily load in, but there is some undesired jank as things recalculate while the scrolling is mid-tween

document.querySelectorAll("img[loading=lazy]").forEach((i) => {
  i.addEventListener("load", (e) => {
    window.dispatchEvent(new Event("resize"));
  });
});

[Cassie]

You can also call

 

ScrollTrigger.refresh()
 

https://greensock.com/docs/v3/Plugins/ScrollTrigger/refresh()

[walpolea]

Thanks! This works. I wrote this off because I had tried:

const sm = SccrollSmoother.create(...)                                
//... then later
sm.scrollTrigger.refresh()

Which did not work.

[Superloop]

6 hours ago, walpolea said:

Thanks! This works. I wrote this off because I had tried:

const sm = SccrollSmoother.create(...)                                
//... then later
sm.scrollTrigger.refresh()

Which did not work.

Oh nice!! This works for me 

[GreenSock]

Yeah, I definitely wouldn't call .refresh() after every single image load - I'd set up a simple queue system that only calls ScrollTrigger.refresh() once ALL of the images finish loading. 

[Superloop]

 

12 hours ago, walpolea said:

Thanks! This works. I wrote this off because I had tried:

const sm = SccrollSmoother.create(...)                                
//... then later
sm.scrollTrigger.refresh()

Which did not work.

 

I made some tests but it doesn't work... I edit my codepen. You will see you can get "last" div. 

See the Pen OJzQgRQ by marctaule (@marctaule) on CodePen.

 

If I use refresh in every image loaded, it seems that works but there are some performance problems.
 

document.addEventListener('lazyloaded', function(e){
	smoother.ScrollTrigger.refresh();
});

 

[walpolea]

I think it's less performance problems and more that the refresh stops the existing scroll tween, causing a stuttering effect. Given the nature of lazy-loaded images (which load as you scroll them near the viewport) I'm not sure there is much to be done, perhaps wait until the velocity is closer to 0 like this:

let needsToRefresh = false;

document.addEventListener('lazyloaded', function(e){
  needsToRefresh = true;
  refresh();
});

function refresh() {
  if( needsToRefresh && smoother.getVelocity() < 0.01 ) {
    ScrollTrigger.refresh();    
    needsToRefresh = false;
  } else if( needsToRefresh ) {
    requestAnimationFrame(refresh);
  }
}

Still not the best experience. Definitely the killer feature would be for gsap to somehow not stop the scrolling tween as ScrollTrigger refreshes.

[GreenSock]

4 hours ago, Marc Taule said:

If I use refresh in every image loaded, it seems that works but there are some performance problems.

You had a typo in your code that was throwing an error. I'm not sure why you were trying to call .refresh() on the smoother's ScrollTrigger (before your images even loaded). 

 

I didn't realize you were using a different library and only loading the images on-demand. In that case, yes, you'd need to at least call .refresh() on the individual ScrollTrigger associated with that newly-loaded image.

 

Originally, I thought you were just starting the load of all the images after your page loaded (without the images), so this is what I was talking about: 

function onLoadImages(selector, callback) {
  let images = gsap.utils.toArray(selector),
      onLoad = e => {
        images.splice(images.indexOf(e.target), 1);
        images.length || callback();
      };
  images.forEach(img => img.addEventListener("load", onLoad));
}
onLoadImages(".lazyload", ScrollTrigger.refresh);

But of course that won't work if you're only loading each one when the scroll reaching a certain position. 

 

I have made some improvements in the next release which I'm using in this fork: 

See the Pen KKZovwj?editors=0010 by GreenSock (@GreenSock) on CodePen.

 

Does that behave more like what you hoped? 

[Stoggy]

On 4/7/2022 at 7:07 AM, GreenSock said:

You had a typo in your code that was throwing an error. I'm not sure why you were trying to call .refresh() on the smoother's ScrollTrigger (before your images even loaded). 

 

I didn't realize you were using a different library and only loading the images on-demand. In that case, yes, you'd need to at least call .refresh() on the individual ScrollTrigger associated with that newly-loaded image.

 

Originally, I thought you were just starting the load of all the images after your page loaded (without the images), so this is what I was talking about: 

function onLoadImages(selector, callback) {
  let images = gsap.utils.toArray(selector),
      onLoad = e => {
        images.splice(images.indexOf(e.target), 1);
        images.length || callback();
      };
  images.forEach(img => img.addEventListener("load", onLoad));
}
onLoadImages(".lazyload", ScrollTrigger.refresh);

But of course that won't work if you're only loading each one when the scroll reaching a certain position. 

 

I have made some improvements in the next release which I'm using in this fork: 

 

 

 

Does that behave more like what you hoped? 

That works like charm for me! 

[KeviinCosmos]

On 4/5/2022 at 10:57 PM, walpolea said:

I ran into the same issue with a tabbed component changing the content height. The only solution I found was to dispatch a resize event which ScrollTrigger refreshes values on pretty gracefully.

window.dispatchEvent(new Event("resize"));

 

This also works as images lazily load in, but there is some undesired jank as things recalculate while the scrolling is mid-tween

document.querySelectorAll("img[loading=lazy]").forEach((i) => {
  i.addEventListener("load", (e) => {
    window.dispatchEvent(new Event("resize"));
  });
});

THANK YOU SOOOO MUCH!!!!! ❤️