linux-packaging-mono/mcs/class/referencesource/System/compmod/system/componentmodel/DefaultValueAttribute.cs

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

namespace System.ComponentModel {

    using System;
    using System.ComponentModel;
    using System.Diagnostics;
    using System.Globalization;
    using System.Runtime.InteropServices;
#if !SILVERLIGHT
    using System.Runtime.Serialization.Formatters;
#endif
    using System.Security.Permissions;

    /// <devdoc>
    ///    <para>Specifies the default value for a property.</para>
    /// </devdoc>
#if !SILVERLIGHT
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1019:DefineAccessorsForAttributeArguments")]
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes")]
#endif
    [AttributeUsage(AttributeTargets.All)]
    public class DefaultValueAttribute : Attribute {
        /// <devdoc>
        ///     This is the default value.
        /// </devdoc>
        private object value;

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class, converting the
        ///    specified value to the
        ///    specified type, and using the U.S. English culture as the
        ///    translation
        ///    context.</para>
        /// </devdoc>
        public DefaultValueAttribute(Type type, string value) {
        
            // The try/catch here is because attributes should never throw exceptions.  We would fail to
            // load an otherwise normal class.
            try {
#if !SILVERLIGHT
                this.value = TypeDescriptor.GetConverter(type).ConvertFromInvariantString(value);
#else
                if (type.IsEnum) {
                    this.value = Enum.Parse(type, value, true);
                } else if (type == typeof(TimeSpan)) {
                    this.value = TimeSpan.Parse(value);
                } else if (type.Module == typeof(string).Module) {
                    this.value = Convert.ChangeType(value, type, CultureInfo.InvariantCulture);
                }
#endif
            }
            catch {
#if !SILVERLIGHT
                Debug.Fail("Default value attribute of type " + type.FullName + " threw converting from the string '" + value + "'.");
#else
                Debug.WriteLine("Default value attribute of type " + type.FullName + " threw converting from the string '" + value + "'.");
#endif
            }
        }

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a Unicode
        ///    character.</para>
        /// </devdoc>
        public DefaultValueAttribute(char value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using an 8-bit unsigned
        ///    integer.</para>
        /// </devdoc>
        public DefaultValueAttribute(byte value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a 16-bit signed
        ///    integer.</para>
        /// </devdoc>
        public DefaultValueAttribute(short value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a 32-bit signed
        ///    integer.</para>
        /// </devdoc>
        public DefaultValueAttribute(int value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a 64-bit signed
        ///    integer.</para>
        /// </devdoc>
        public DefaultValueAttribute(long value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a
        ///    single-precision floating point
        ///    number.</para>
        /// </devdoc>
        public DefaultValueAttribute(float value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a
        ///    double-precision floating point
        ///    number.</para>
        /// </devdoc>
        public DefaultValueAttribute(double value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a <see cref='System.Boolean'/>
        /// value.</para>
        /// </devdoc>
        public DefaultValueAttribute(bool value) {
            this.value = value;
        }
        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/> class using a <see cref='System.String'/>.</para>
        /// </devdoc>
        public DefaultValueAttribute(string value) {
            this.value = value;
        }

        /// <devdoc>
        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.DefaultValueAttribute'/>
        /// class.</para>
        /// </devdoc>
        public DefaultValueAttribute(object value) {
            this.value = value;
        }

        /// <devdoc>
        ///    <para>
        ///       Gets the default value of the property this
        ///       attribute is
        ///       bound to.
        ///    </para>
        /// </devdoc>
        public virtual object Value {
            get {
                return value;
            }
        }

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

            DefaultValueAttribute other = obj as DefaultValueAttribute;

            if (other != null) {
                if (Value != null) {
                    return Value.Equals(other.Value);
                }
                else {
                    return (other.Value == null);           
                }
            }
            return false;
        }

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

        protected void SetValue(object value) {
            this.value = value;
        }
    }
}