[Android] Fix for CollectionView.EmptyView does not remeasure its height when the parent layout changes dynamically, causing incorrect sizing.

[BagavathiPerumal]

Note

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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!

Root Cause:

The issue occurs because of Android RecyclerView reusing ViewHolders with previously measured dimensions and not automatically remeasuring them when only the layout size changes, causing the EmptyView to retain its old dimensions instead of adapting to the new available space.

Fix Description:

The fix involves explicitly forcing the EmptyView to remeasure when the RecyclerView dimensions change by detecting width or height updates, locating the corresponding EmptyView ViewHolder, and requesting a layout pass so it is resized to match the new available space. When the ViewHolder isn't immediately available, the layout request is deferred to the next UI loop iteration.

Issues Fixed

Fixes #33324

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Output Screenshot

Before Issue Fix	After Issue Fix
CollectionViewLayoutIssue-BeforeFix.mov	CollectionViewLayoutIssue-AfterFix.mov

[sheiksyedm]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[Copilot]

Pull request overview

Fixes an Android CollectionView EmptyView sizing issue where the empty view can retain stale measured dimensions after the parent layout size changes.

Changes:

• Android handler: detect RecyclerView size changes and trigger an EmptyView layout pass when the size updates.
• Add a new issue page (Issue33324) to reproduce the scenario via dynamic layout changes.
• Add a UI screenshot test and new Android/iOS snapshot baselines for EmptyViewShouldRemeasureWhenParentLayoutChanges.

Reviewed changes

Copilot reviewed 3 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Controls/src/Core/Handlers/Items/ItemsViewHandler.Android.cs	Forces the EmptyView ViewHolder to re-layout when RecyclerView size changes.
src/Controls/tests/TestCases.HostApp/Issues/Issue33324.cs	Adds a repro page that changes layout dynamically to validate EmptyView remeasurement behavior.
src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue33324.cs	Adds a screenshot-based UI test for the repro scenario.
src/Controls/tests/TestCases.Android.Tests/snapshots/android/EmptyViewShouldRemeasureWhenParentLayoutChanges.png	Adds Android baseline screenshot for the new test.
src/Controls/tests/TestCases.iOS.Tests/snapshots/ios/EmptyViewShouldRemeasureWhenParentLayoutChanges.png	Adds iOS baseline screenshot for the new test.

[Copilot]

After tapping "LoadItemsButton", this waits for "SecondCollectionView", which is already present before the tap. That means the test can take the screenshot before the layout change occurs (or before items become visible), making the test ineffective/flaky. Consider waiting for a UI change caused by the command (e.g., the now-visible "FirstCollectionView" inside the previously-hidden container, or a specific item) before calling VerifyScreenshot().

Suggested change

	App.WaitForElement("SecondCollectionView");
	App.WaitForElement("FirstCollectionView");

[Copilot]

The size-change tolerance is a magic number. Consider extracting it to a named const/static readonly (and adding a brief comment explaining the unit/why that tolerance was chosen) so future changes are easier and intent is clearer.

[PureWeen]

/rebase