[Android] CarouselView: Fix scroll to last item after data reset in loop mode

[SyedAbdulAzeemSF4852]

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Issue Details :

• When the item source is reloaded and items are added dynamically, updating the CurrentItem to one of the last items correctly changes the property, but the carousel fails to visually scroll to that position.

Root Cause:

• When ScrollToPosition(carouselPosition) was called with a logical position like 0 (i.e., the CarouselView position), it scrolled to the raw adapter position 0. However, position 0 in the virtualized array represented the beginning of the full range, which was not the correct location for proper looping behavior. As a result, the center position was set to 0. Then, when attempting to scroll backward, the logic subtracted the target item index from this center position (0), leading to negative values.
• This caused the scroll operation to fail, and no scrolling took place.

Description of Change

• Updated GetGoToIndex in CarouselViewLoopManager.cs to correctly handle empty item sources and fix the calculation for determining the shortest scroll path in loop mode.
• Added a new helper method UpdateLoopCentering to MauiCarouselRecyclerView.cs that recalculates and centers the carousel on the correct item when in loop mode, both after collection changes and during initial position updates. This ensures the view is properly centered even after resetting the data or changing the selected item.

Issues Fixed

Fixes #23023

Validated the behaviour in the following platforms

• Windows - Test fails on Windows — tracked in #31670
• Android
• iOS
• Mac

Output

Before	After
Before.mov	After.mov

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[Copilot]

Pull Request Overview

Fixes incorrect centering/scrolling behavior of CarouselView (loop mode) on Android after the ItemsSource is reset and CurrentItem points to a tail item.
Key changes:

• Adjusted loop index calculation in GetGoToIndex to use modular arithmetic and added bounds/empty checks.
• Added UpdateLoopCentering helper and invoked it after collection changes and during initial position setup when looping.
• Added a new UI test (Issue23023) and corresponding host page to reproduce and validate the scenario.

Reviewed Changes

Copilot reviewed 4 out of 7 changed files in this pull request and generated 3 comments.

File	Description
src/Controls/src/Core/Handlers/Items/Android/CarouselViewLoopManager.cs	Corrects loop navigation index calculations and adds input validation.
src/Controls/src/Core/Handlers/Items/Android/MauiCarouselRecyclerView.cs	Introduces UpdateLoopCentering to properly center after resets and refactors initial positioning logic.
src/Controls/tests/TestCases.HostApp/Issues/Issue23023.cs	Adds a repro page with looping CarouselView and controls to reload items and scroll to last item.
src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue23023.cs	Adds UI test exercising reload + scroll-to-last-item scenario (currently wrapped in a conditional compilation symbol).

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 31672

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 31672"

[SyedAbdulAzeemSF4852]

Addressed concerns raised in the AI summary.

[kubaflo]

The test failed

[SyedAbdulAzeemSF4852]

The test failed

@kubaflo , I checked the test locally — it passes with the fix and fails without it. I’ve added the test output below for your reference.

With_Fix	Without_Fix

[kubaflo]

/azp run maui-pr-uitests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[sheiksyedm]

/azp run maui-pr-uitests , maui-pr-devicetests

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[MauiBot]

🧪 UI Test Results

🧪 a9e40b6 · Fix formatting and remove hardcoded index value · 2026-04-22 18:41 UTC

Build #1391112 | 🔄 inProgress | / passed (0%)

🎯 Detected categories: CarouselView,CollectionView — ran 17 of 143 matrix cells (skipped 126)