Xamarin.forms: Ability to hide HomeIndicator from iPhone X, XR, XS on given page

[PawKanarek]

Summary

Ability to hide HomeIndicator from iPhone X, XR, XS on given page

API Changes

add to Xamarin.Forms.Platform.iOS/PlatformRenderer.cs

public override UIViewController ChildViewControllerForHomeIndicatorAutoHidden
{
    get
    {
         return (UIViewController)Platform.GetRenderer(this.Platform.Page);
    }
}
... 
public override void ViewDidLoad()
{
       ...
       SetNeedsUpdateOfHomeIndicatorAutoHidden();
}

and add new bindable property to page and consume it in Page Renderer

[assembly: ExportRenderer(typeof(MyPage), typeof(HomeIndicatorRenderer))]
namespace MyApp
{ 
    public class HomeIndicatorRenderer : PageRenderer
    {
        // new property
        public override bool PrefersHomeIndicatorAutoHidden => this.Element.HomeIndicatorAutoHiddenIOS;

        public override void ViewDidAppear(bool animated)
        {
            base.ViewDidAppear(animated);
            SetNeedsUpdateOfHomeIndicatorAutoHidden();
        }
    }
}

Intended Use Case

Applicable to all pages where user don't want to be distracted by home indicator, e.g. full-screen gallery window or full-screen player window.

[jfversluis]

Originated here: https://stackoverflow.com/questions/54743272/hide-home-indicator-for-iphone-x-in-xamarin-forms-page/54747722

There was already a PR for it a while ago (#1515) but this was closed for lack of spec.

I would suggest making it a platform-specific though, similar to how it works for the iOS status bar.

This would mean

API Changes

Added:
Page iOS Platform Specific

public static readonly BindableProperty HomeIndicatorAutoHiddenProperty = BindableProperty.Create(nameof(HomeIndicatorAutoHidden), typeof(bool), typeof(Page), false);

public static bool GetHomeIndicatorAutoHidden(BindableObject element)
public static void SetHomeIndicatorAutoHidden(BindableObject element, bool value)
public static IPlatformElementConfiguration<iOS, FormsElement> SetHomeIndicatorAutoHidden(this IPlatformElementConfiguration<iOS, FormsElement> config, bool value)
public static bool HomeIndicatorAutoHidden(this IPlatformElementConfiguration<iOS, FormsElement> config)

[bcaceiro]

Is it possible to hide the indicator in all application? At the moment, I have this property on my BasecontentPage, however, everytime I do an action, or change page, the indicator is always appearing and disappearing (which is far from perfect)