use one rAF manager

[snewcomer]

Huge thanks to the work done in #103

Also splits out the recursive rAF function to it's own service.

close #103

[snewcomer]

@jheth Hey Joe 👋 Would you mind trying out this branch? This uses an rAFPoolManager to use one rAF for all your components on the page. Also, I realized we use a concept called viewportSpy. By default it is false (may change the default in the future). But viewportSpy -

When false, the Mixin will only watch the Component until it enters the viewport once

I short circuited the rAF calls if viewportSpy is kept as the default (false), so rAF will stop running if your component enters the viewport once.

[jheth]

This looks great! I'll give it a try.

[snewcomer]

@jheth I'll wait for your confirmation before merging 👍

[jheth]

@snewcomer The branch is much improved over the previous where I was seeing rAF for each LazyImage component I had on the page. However, I'm not seeing the rAF ever stop, even after all images are loaded.

This is a performance chart on page load with 10 lazy image components on the page.

This is a close up, showing a single rAF is being used, which is much better than before. 👍

This is a performance chart after scrolling to the bottom of the page and all images had been scrolled into the viewport. I don't see a difference from the first chart. I would have expected no more rAF requests.

[snewcomer]

@jheth Do you have viewportSpy set to true (ensures continuous rAF calls, default is false)? Here, we are trying to set _stopListening to true.

Here and here.

Let me know what you have set for this property.

[jheth]

I do not have viewportSpy enabled, it's using the default of false.

[snewcomer]

@jheth I added a test with one slightly small regression. Lmk if you see anything different. Otherwise, perhaps simplify things by putting one image on the page and put a debugger here and ensure _stopListening is true.

[snewcomer]

@jheth Also you can test this behavior (of turning off rAF after first entering the viewport) in the dummy app on the rAF route. I'll merge as is if you don't mind and we can make further improvements in the future.

Thanks again for everything here.