//------------------------------------------------------------------------------
// <copyright file="EditorAttribute.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
//------------------------------------------------------------------------------

/*
 */
namespace System.ComponentModel {
    
    using System.Diagnostics;
    using System.Globalization;
    using System.Security.Permissions;
                                
    /// <devdoc>
    ///    <para>Specifies the editor to use to change a property. This class cannot be inherited.</para>
    /// </devdoc>
    [AttributeUsage(AttributeTargets.All, AllowMultiple = true, Inherited = true)]
    public sealed class EditorAttribute : Attribute {

        private string baseTypeName;
        private string typeName;
        private string typeId;
        
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.EditorAttribute'/> class with the default editor, which is
        ///    no editor.</para>
        /// </devdoc>
        public EditorAttribute() {
            this.typeName = string.Empty;
            this.baseTypeName = string.Empty;
        }

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.EditorAttribute'/> class with the type name and base type
        ///    name of the editor.</para>
        /// </devdoc>
        public EditorAttribute(string typeName, string baseTypeName) {
            string temp = typeName.ToUpper(CultureInfo.InvariantCulture);
            Debug.Assert(temp.IndexOf(".DLL") == -1, "Came across: " + typeName + " . Please remove the .dll extension");
            this.typeName = typeName;
            this.baseTypeName = baseTypeName;
        }

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.EditorAttribute'/> class.</para>
        /// </devdoc>
        public EditorAttribute(string typeName, Type baseType) {
            string temp = typeName.ToUpper(CultureInfo.InvariantCulture);
            Debug.Assert(temp.IndexOf(".DLL") == -1, "Came across: " + typeName + " . Please remove the .dll extension");
            this.typeName = typeName;
            this.baseTypeName = baseType.AssemblyQualifiedName;
        }

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.EditorAttribute'/>
        /// class.</para>
        /// </devdoc>
        public EditorAttribute(Type type, Type baseType) {
            this.typeName = type.AssemblyQualifiedName;
            this.baseTypeName = baseType.AssemblyQualifiedName;
        }

        /// <devdoc>
        ///    <para>Gets the name of the base class or interface serving as a lookup key for this editor.</para>
        /// </devdoc>
        public string EditorBaseTypeName {
            get {
                return baseTypeName;
            }
        }

        /// <devdoc>
        ///    <para>Gets the name of the editor class.</para>
        /// </devdoc>
        public string EditorTypeName {
            get {
                return typeName;
            }
        }
    
        /// <internalonly/>
        /// <devdoc>
        ///    <para>
        ///       This defines a unique ID for this attribute type. It is used
        ///       by filtering algorithms to identify two attributes that are
        ///       the same type. For most attributes, this just returns the
        ///       Type instance for the attribute. EditorAttribute overrides
        ///       this to include the type of the editor base type.
        ///    </para>
        /// </devdoc>
        public override object TypeId {
            get {
                if (typeId == null) {
                    string baseType = baseTypeName;
                    int comma = baseType.IndexOf(',');
                    if (comma != -1) {
                        baseType = baseType.Substring(0, comma);
                    }
                    typeId = GetType().FullName + baseType;
                }
                return typeId;
            }
        }

        public override bool Equals(object obj) {
            if (obj == this) {
                return true;
            }

            EditorAttribute other = obj as EditorAttribute;

            return (other != null) && other.typeName == typeName && other.baseTypeName == baseTypeName;
        }

        public override int GetHashCode() {
            return base.GetHashCode();
        }
    }
}