For a component like Accompanist HorizontalPager, ...

# compose

[yschimke]

For a component like Accompanist HorizontalPager, the docs state

Pages in both HorizontalPager and VerticalPager are lazily composed and laid-out as required by the layout. As the user scrolls through pages, any pages which are no longer required are removed from the content.

Does this mean it is safe to use LaunchedEffect as a signal that the current page is just been shown? Or do they get created eagerly when user is contemplating a scroll/starting a swipe?

Should pager state change events be used instead?

[cb]

A LaunchedEffect reading what state? But yes, just use the PagerState.currentPage, it's what it is there for

[yschimke]

Thanks, that's perfect. It's actually going to be a DisposableEffect, needs to set up an event listener when the page goes on screen, and removes it when it leaves, replaced by handler in UI on another page. So sounds like I've introduced a bug using anything triggered on Composition, rather than the currentPage.

[Albert Chang]

Note that `LaunchedEffect`/`DisposableEffect` won't work as you expected in a lazy list. As Chris suggested, currentPage is what you should use. See this.