Unplanned
Last Updated: 18 Sep 2024 11:34 by ADMIN
Matthew
Created on: 17 Sep 2024 20:31
Category: CollectionView
Type: Feature Request
4
CollectionView: Add support for sticky group headers

Add support for sticky group headers (iOS, Android)

This feature is available in the ListView control. E.g. On iOS using the built-in CollectionView it can be added this way:

public class CollectionViewPlatformHandler : CollectionViewHandler { /// <inheritdoc /> protected override ItemsViewLayout SelectLayout() { var layout = base.SelectLayout(); if (ItemsView.IsGrouped && layout is UICollectionViewFlowLayout flowLayout) { // Enable sticky section headers. flowLayout.SectionHeadersPinToVisibleBounds = true; } return layout; } }

Add support for scrollable index titles (iOS).

This feature is available in the ListView control. E.g. On iOS using the built-in CollectionView it can be added this way:

    public class CollectionViewPlatformHandler : CollectionViewHandler
    {
        /// <inheritdoc />
        protected override UIView CreatePlatformView()
        {
            var platformView = base.CreatePlatformView();
            if (ItemsView.IsGrouped && ItemsView.ItemsSource is IEnumerable<IGrouping<string, object>> groups && platformView.Subviews[0] is UICollectionView collectionView)
            {
                // Enable index titles.
                collectionView.DataSource = new GroupedCollectionViewDataSource(collectionView.DataSource, groups.Select(q => q.Key));
            }

            return platformView;
        }
        
        private class GroupedCollectionViewDataSource(IUICollectionViewDataSource datasource, IEnumerable<string> sections) : UICollectionViewDataSource
        {
            public override nint NumberOfSections(UICollectionView collectionView) => datasource.NumberOfSections(collectionView);
            public override nint GetItemsCount(UICollectionView collectionView, nint section) => datasource.GetItemsCount(collectionView, section);
            public override UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath) => datasource.GetCell(collectionView, indexPath);
            public override UICollectionReusableView GetViewForSupplementaryElement(UICollectionView collectionView, NSString elementKind, NSIndexPath indexPath) => datasource.GetViewForSupplementaryElement(collectionView, elementKind, indexPath);
            public override string[] GetIndexTitles(UICollectionView collectionView) => sections.ToArray();
        }
    }
 

Note: This is available out-of-the-box on iOS 14 and above for a native UICollectionView. See documentation.

https://developer.apple.com/documentation/uikit/uicollectionviewdatasource/2851455-indextitlesforcollectionview

3 comments
ADMIN
Didi
Posted on: 18 Sep 2024 11:34

Hi Matthew,

The Telerik MAUI CollectionView does not depend on the native iOS CollectionView. In general, the Telerik MAUI CollectionView is not a native control as the Telerik MAUI RadListView.

I have logged this feature for all platforms as I think such feature will be a good addition to the control's features set. Here is the link: https://feedback.telerik.com/maui/1664774-collectionview-add-support-for-scrollable-index-titles 

If you have any additional feedback and comments on the Telerik MAUI RadCollectionView, let me know.

Regards,
Didi
Progress Telerik

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Matthew
Posted on: 18 Sep 2024 10:56

Thanks Didi.

Unfortunately Android's RecyclerView does not have a built-in feature for index titles (like the right-aligned, scrollable list of titles in UICollectionView on iOS) for quick navigation. However it may be possible to implement using "fast-scroll support" e.g. https://medium.com/android-news/fast-scrolling-with-recyclerview-2b89d4574688

However it would be sufficient to implement this on iOS only initially since it is supported out-of-the-box.

Regards,

Matthew

ADMIN
Didi
Posted on: 18 Sep 2024 10:32

Hi Matthew,

Thank you for your feedback. 

I noticed you listed two different requests here. I will separate them as they are different requests. I will keep the first in this item and will log the second separately. But to be sure I understand your point could you please share whether the requested scenario for scrollable index title is only on iOS?

Looking forward to your reply.

Regards,
Didi
Progress Telerik