Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/UI/IDReferencePropertyAttribute.cs

@@ -0,0 +1,80 @@
+//------------------------------------------------------------------------------
+// <copyright file="IDReferencePropertyAttribute.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI
+{
+    using System;
+    using System.Diagnostics.CodeAnalysis;
+
+    /// <devdoc>
+    /// An IDReferencePropertyAttribute metadata attribute can be applied to string properties
+    /// that contain ID references.
+    /// This can be used to identify ID reference properties which allows design-time functionality 
+    /// to do interesting things with the property values.
+    /// </devdoc>
+    [AttributeUsage(AttributeTargets.Property)]
+    public sealed class IDReferencePropertyAttribute : Attribute
+    {
+
+        private Type _referencedControlType;
+
+
+        /// <devdoc>
+        /// </devdoc>
+        public IDReferencePropertyAttribute()
+            : this(typeof(Control))
+        {
+        }
+
+
+        /// <devdoc>
+        /// Used to mark a property as an ID reference. In addition, the type of controls
+        /// can be specified.
+        /// </devdoc>
+        public IDReferencePropertyAttribute(Type referencedControlType)
+        {
+            _referencedControlType = referencedControlType;
+        }
+
+
+        /// <devdoc>
+        /// The types of controls allowed by the property.
+        /// </devdoc>
+        public Type ReferencedControlType
+        {
+            get
+            {
+                return _referencedControlType;
+            }
+        }
+
+
+        /// <internalonly/>
+        [SuppressMessage("Microsoft.Usage", "CA2303:FlagTypeGetHashCode", Justification = "The types are Sytem.Web.UI.Control derived classes and not com interop types.")]
+        public override int GetHashCode()
+        {
+            return ((ReferencedControlType != null) ? ReferencedControlType.GetHashCode() : 0);
+        }
+
+
+        /// <internalonly/>
+        public override bool Equals(object obj)
+        {
+            if (obj == this)
+            {
+                return true;
+            }
+
+            IDReferencePropertyAttribute other = obj as IDReferencePropertyAttribute;
+            if (other != null)
+            {
+                return (ReferencedControlType == other.ReferencedControlType);
+            }
+
+            return false;
+        }
+    }
+}