[iOS] Fixed HeaderFooterGrid to pass on CV1 and CV2

[devanathan-vaithiyanathan]

Issue details

The size of the CollectionView, including the header and footer, is not rendered correctly on the UI in CV1 but displays correctly in CV2.

Root cause

The GetSize() method calculated the size of the CollectionView based only on its content, ignoring the header and footer sizes. This caused incorrect height or width rendering when a header or footer was used.

Description of Change

The fix calculates the sizes of the header and footer using helper methods, This ensures the total size includes all elements, and the result is adjusted to fit within the CollectionView bounds.

Issues Fixed

Fixes #25773

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Output Screenshot

Before	After

[jsuarezruiz]

/azp run

[azure-pipelines]

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[rmarinho]

It s failing some tests..

https://dev.azure.com/xamarin/public/_apis/test/Runs/3418613/Results/100053/Attachments/14

[rmarinho]

Could this be CV2 failing

[devanathan-vaithiyanathan]

Could this be CV2 failing

Hi @rmarinho,

In CV1, It appears that the VerticalItemsSpacing in the GridItemsLayout is creating excessive spacing in the last section of the items layout. The build failures are due to these ItemSpacing discrepancies, resulting in snapshot mismatches.

The following Issue was previously identified and resolved, and a separate PR was created.

PR Link Reference => #25825

In this Focused PR, We have made targeted changes specifically to resolve the VerticalItemsSpacing issue for the last section of CV items. We expect the next CI run to pass with these updates.

Code Changes :
https://github.com/dotnet/maui/blob/0e5aabf62ed9ec4213066de39b090a20f93a414d/src/Controls/src/Core/Handlers/Items/iOS/ItemsViewLayout.cs#L136C4-L141C5

Please review the PR and let us know if any further clarification.

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[devanathan-vaithiyanathan]

@rmarinho,

We have attached the original and error snapshot images for reference. As highlighted by the difference between the two, there is a noticeable pixel error in the layout of the header and footer Grid in the CV1 snapshot.

Would it be possible to replace the header and footer Grid image for this case or are there other adjustments we can make to resolve this pixel discrepancy? Please share your thoughts on this.

Looking forward to your feedback! Thank you in advance.

[rmarinho]

Can we try replace the image to check if it passes?

[devanathan-vaithiyanathan]

Can we try replace the image to check if it passes?

Thank you for the suggestion. We will replace the header and footer Grid images to check if the build passes with the updated snapshot.

[rmarinho]

/azp run

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Azure Pipelines successfully started running 3 pipeline(s).

[rmarinho]

/rebase