Just Simple Alternative

In my case, i am using infinite builder by default. no itemCount. and my list is widget.images .

PageView.builder(
    controller: _pageController,
    allowImplicitScrolling: true,
    itemBuilder: (context, index) {
      final url = widget.images[index % widget.images.length];
      return InteractiveViewer(maxScale: 3, child: Image.asset(url));
    },
),

But also, i want to view initial page, so i manage using _pageController . To initialize _pageController , i sent initialIndex for example index 2.
When i snap to right, infinite looping work. after i reach last page, the page show first page again and keep going.

But !!, when i star over again. after pageview show initial page then i snap to left, infinite loop not work. from this i learn that is pageview default infinite only work for upcoming index.

To fix this, i create schema to handle range page/index e.g. from 0-1000. and create function to calculateActualInitialIndex. to make infinite loop to left direction, i set initialIndex to center of range page. if range 0-1000, then initialIndex will be 500. This will work to infitie loop for left direction until indexValue is 0.

and here to initialize _pageCntroller and calculate initial:

late final PageController _pageController;
static const int _infiniteScrollFactor = 1000; // range for 0-1000

int _calculateInitialPage() {
    return (_infiniteScrollFactor ~/ 2) * widget.images.length + widget.initialIndex;
}

@override
void initState() {
    _pageController = PageController(initialPage: _calculateInitialPage());
    super.initState();
}