File: Interactivity\MultiCondition.cs
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Project: src\src\Controls\src\Core\Controls.Core.csproj (Microsoft.Maui.Controls)
#nullable disable
using System.Collections.Generic;
 
namespace Microsoft.Maui.Controls
{
	internal sealed class MultiCondition : Condition
	{
		readonly BindableProperty _aggregatedStateProperty;
 
		public MultiCondition()
		{
			_aggregatedStateProperty = BindableProperty.CreateAttached("AggregatedState", typeof(bool), typeof(MultiCondition), false, propertyChanged: OnAggregatedStatePropertyChanged);
			Conditions = new TriggerBase.SealedList<Condition>();
		}
 
		public IList<Condition> Conditions { get; }
 
		internal override bool GetState(BindableObject bindable)
		{
			return (bool)bindable.GetValue(_aggregatedStateProperty);
		}
 
		internal override void OnSealed()
		{
			((TriggerBase.SealedList<Condition>)Conditions).IsReadOnly = true;
			foreach (Condition condition in Conditions)
				condition.ConditionChanged = OnConditionChanged;
		}
 
		internal override void SetUp(BindableObject bindable)
		{
			foreach (Condition condition in Conditions)
				condition.SetUp(bindable);
		}
 
		internal override void TearDown(BindableObject bindable)
		{
			foreach (Condition condition in Conditions)
				condition.TearDown(bindable);
		}
 
		void OnAggregatedStatePropertyChanged(BindableObject bindable, object oldValue, object newValue)
		{
			if ((bool)oldValue == (bool)newValue)
				return;
 
			ConditionChanged?.Invoke(bindable, (bool)oldValue, (bool)newValue);
		}
 
		void OnConditionChanged(BindableObject bindable, bool oldValue, bool newValue)
		{
			var oldState = (bool)bindable.GetValue(_aggregatedStateProperty);
			var newState = true;
			foreach (Condition condition in Conditions)
			{
				if (!condition.GetState(bindable))
				{
					newState = false;
					break;
				}
			}
			if (newState != oldState)
				bindable.SetValue(_aggregatedStateProperty, newState);
		}
	}
}