Vertical virtual scroller causing flaky image index change without explicit invocation

[maranmaran]

What is the expected behavior?

Vertical scroll doesn't change item index

What is the current behavior?

Images jitter and jump index on vertical scroll

Two days valid link: https://streamable.com/rguhly

What are the steps to reproduce?

I have virtual scrolling grid.

When I go out of view with the gallery and in fast manner pull the vertical scroll back, sometimes (frequently) I get different item index as my first, and it kind of jumps between few photos.

Stackblitz

I'll post repro issue when I get the time.

Which versions are you using for the following packages?

Angular: 16
Gallery: ^11.0.0

My setup code:

 ngOnDestroy() { this.ref.destroy() }

 private async setupGallery() {
    
    // this gets or creates the ref and adds images to it
    await this.addItemsToGallery(); 

    this.ref.set(0, 'instant'); // set 0 as index - (should see no jumping of images)
  }

The html is wrapped in virtual scroll component.
However, I don't think that should bother it.

My image data are always in consistent order
I'm forcing the index to be set as 0 but even so on init I see this jumping when I scroll or even refresh the page

[MurhafSousli]

I see, yes it is better to have a reproduction, there are couple of options we can try

[MurhafSousli]

Please try with the newer version 12 beta npm i ng-gallery@beta, closing this for now... feel free to reopen if you still encounter the issue

#583