UIHintAttribute.cs

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using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
 
namespace System.ComponentModel.DataAnnotations;
 
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = true)]
public class UIHintAttribute : Attribute
{
    internal sealed class UIHintImplementation
    {
        private readonly object[] _inputControlParameters;
 
        private IDictionary<string, object> _controlParameters;
 
        public string UIHint { get; }
 
        public string PresentationLayer { get; }
 
        public IDictionary<string, object> ControlParameters => _controlParameters ?? (_controlParameters = BuildControlParametersDictionary());
 
        public UIHintImplementation(string uiHint, string presentationLayer, params object[] controlParameters)
        {
            UIHint = uiHint;
            PresentationLayer = presentationLayer;
            if (controlParameters != null)
            {
                _inputControlParameters = new object[controlParameters.Length];
                Array.Copy(controlParameters, _inputControlParameters, controlParameters.Length);
            }
        }
 
        public override int GetHashCode()
        {
            string text = UIHint ?? string.Empty;
            string text2 = PresentationLayer ?? string.Empty;
            return text.GetHashCode() ^ text2.GetHashCode();
        }
 
        public override bool Equals([NotNullWhen(true)] object obj)
        {
            if (!(obj is UIHintImplementation uIHintImplementation) || UIHint != uIHintImplementation.UIHint || PresentationLayer != uIHintImplementation.PresentationLayer)
            {
                return false;
            }
            IDictionary<string, object> controlParameters;
            IDictionary<string, object> controlParameters2;
            try
            {
                controlParameters = ControlParameters;
                controlParameters2 = uIHintImplementation.ControlParameters;
            }
            catch (InvalidOperationException)
            {
                return false;
            }
            if (controlParameters.Count != controlParameters2.Count)
            {
                return false;
            }
            return controlParameters.OrderBy((KeyValuePair<string, object> p) => p.Key).SequenceEqual(controlParameters2.OrderBy((KeyValuePair<string, object> p) => p.Key));
        }
 
        private IDictionary<string, object> BuildControlParametersDictionary()
        {
            IDictionary<string, object> dictionary = new Dictionary<string, object>();
            object[] inputControlParameters = _inputControlParameters;
            if (inputControlParameters == null || inputControlParameters.Length == 0)
            {
                return dictionary;
            }
            if (inputControlParameters.Length % 2 != 0)
            {
                throw new InvalidOperationException(System.SR.UIHintImplementation_NeedEvenNumberOfControlParameters);
            }
            for (int i = 0; i < inputControlParameters.Length; i += 2)
            {
                object obj = inputControlParameters[i];
                object value = inputControlParameters[i + 1];
                if (obj == null)
                {
                    throw new InvalidOperationException(System.SR.Format(System.SR.UIHintImplementation_ControlParameterKeyIsNull, i));
                }
                if (!(obj is string text))
                {
                    throw new InvalidOperationException(System.SR.Format(System.SR.UIHintImplementation_ControlParameterKeyIsNotAString, i, inputControlParameters[i].ToString()));
                }
                if (dictionary.ContainsKey(text))
                {
                    throw new InvalidOperationException(System.SR.Format(System.SR.UIHintImplementation_ControlParameterKeyOccursMoreThanOnce, i, text));
                }
                dictionary[text] = value;
            }
            return dictionary;
        }
    }
 
    private readonly UIHintImplementation _implementation;
 
    public string UIHint => _implementation.UIHint;
 
    public string? PresentationLayer => _implementation.PresentationLayer;
 
    public IDictionary<string, object?> ControlParameters => _implementation.ControlParameters;
 
    public UIHintAttribute(string uiHint)
        : this(uiHint, null, Array.Empty<object>())
    {
    }
 
    public UIHintAttribute(string uiHint, string? presentationLayer)
        : this(uiHint, presentationLayer, Array.Empty<object>())
    {
    }
 
    public UIHintAttribute(string uiHint, string? presentationLayer, params object?[]? controlParameters)
    {
        _implementation = new UIHintImplementation(uiHint, presentationLayer, controlParameters);
    }
 
    public override int GetHashCode()
    {
        return _implementation.GetHashCode();
    }
 
    public override bool Equals([NotNullWhen(true)] object? obj)
    {
        if (obj is UIHintAttribute uIHintAttribute)
        {
            return _implementation.Equals(uIHintAttribute._implementation);
        }
        return false;
    }
}