maui-linux/Xamarin.Forms.Core/BindableObjectExtensions.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq.Expressions;

namespace Xamarin.Forms
{
	public static class BindableObjectExtensions
	{
		internal static void PropagateBindingContext<T>(this BindableObject self, IList<T> children)
		{
			PropagateBindingContext(self, children, BindableObject.SetInheritedBindingContext);
		}

		internal static void PropagateBindingContext<T>(this BindableObject self, IList<T> children, Action<BindableObject, object> setChildBindingContext)
		{
			if (children == null || children.Count == 0)
				return;

			var bc = self.BindingContext;

			for (var i = 0; i < children.Count; i++)
			{
				var bo = children[i] as BindableObject;
				if (bo == null)
					continue;

				setChildBindingContext(bo, bc);
			}
		}

		public static void SetBinding(this BindableObject self, BindableProperty targetProperty, string path, BindingMode mode = BindingMode.Default, IValueConverter converter = null,
									  string stringFormat = null)
		{
			if (self == null)
				throw new ArgumentNullException("self");
			if (targetProperty == null)
				throw new ArgumentNullException("targetProperty");

			var binding = new Binding(path, mode, converter, stringFormat: stringFormat);
			self.SetBinding(targetProperty, binding);
		}

		[Obsolete]
		[EditorBrowsable(EditorBrowsableState.Never)]
		public static void SetBinding<TSource>(this BindableObject self, BindableProperty targetProperty, Expression<Func<TSource, object>> sourceProperty, BindingMode mode = BindingMode.Default,
											   IValueConverter converter = null, string stringFormat = null)
		{
			if (self == null)
				throw new ArgumentNullException(nameof(self));
			if (targetProperty == null)
				throw new ArgumentNullException(nameof(targetProperty));
			if (sourceProperty == null)
				throw new ArgumentNullException(nameof(sourceProperty));

			Binding binding = Binding.Create(sourceProperty, mode, converter, stringFormat: stringFormat);
			self.SetBinding(targetProperty, binding);
		}
	}
}