[Enhancement] Horizontal ListView

[PureWeen]

Rationale

ListView control currently can only flow items vertically. This will add the ability to flow the items horizontally.

Implementation

public enum ListViewOrientation
	{
		Vertical,
		Horizontal
	}

public static readonly BindableProperty OrientationProperty = BindableProperty.Create(nameof(Orientation), typeof(ListViewOrientation), typeof(ListView), ListViewOrientation.Vertical,
			propertyChanged: (bindable, oldvalue, newvalue) => ((ListView)bindable).InvalidateLayout());

Expected Result

Android

• ListView.Orientation: should indicate the directions items flow

iOS

See Android

UWP

See Android

Implications for CSS

Backward Compatibility

If not specified just ensure that no behavior changes and that items by default flow vertically

Difficulty : Medium

[samhouts]

Some things that might be problematic:

1. Pull-to-refresh. Would we want to have a horizontal swipe initiate this, or just have this be unsupported?
2. ContextActions on iOS. These are currently activated with a horizontal swipe, which will conflict with the scrolling now. Do we want to change the swipe direction? Not support it?

[jassmith]

1. I think for now that should be unsupported

2. We will need to change the swipe direction I think.

[weitzhandler]

Related #1718.

Anyway, the lack of ItemsControl and horizontal ListView is extremely painful!
Xamarin has a quirky fixation to bias everything towards mobile and completely ignore anything else. Time has passed and we want to start using Xamarin for bigger screen too, and also for desktops.
The lack of horizontal support, better keyboard and mouse control is totally annoying!

[samhouts]

Since #3172 CollectionView will support Horizontal mode, is it possible that this is no longer needed as a feature of ListView?

[davidortinau]

Closing it. As @samhouts mentioned, CollectionView handles this case.