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//------------------------------------------------------------------------------
// <copyright file="EnumConverter.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
*/
namespace System.ComponentModel {
using Microsoft.Win32;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.Serialization.Formatters;
using System.Runtime.Remoting;
using System.Runtime.InteropServices;
using System.Security.Permissions;
/// <devdoc>
/// <para>Provides a type converter to convert <see cref='System.Enum'/>
/// objects to and from various
/// other representations.</para>
/// </devdoc>
[HostProtection(SharedState = true)]
public class EnumConverter : TypeConverter {
/// <devdoc>
/// <para>
/// Provides a <see cref='System.ComponentModel.TypeConverter.StandardValuesCollection'/> that specifies the
/// possible values for the enumeration.
/// </para>
/// </devdoc>
private StandardValuesCollection values;
/// <devdoc>
/// <para>
/// Specifies
/// the
/// type of the enumerator this converter is
/// associated with.
/// </para>
/// </devdoc>
private Type type;
/// <devdoc>
/// <para>
/// Initializes a new instance of the <see cref='System.ComponentModel.EnumConverter'/> class for the given
/// type.
/// </para>
/// </devdoc>
public EnumConverter(Type type) {
this.type = type;
}
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
protected Type EnumType {
get {
return type;
}
}
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
protected StandardValuesCollection Values {
get {
return values;
}
set {
values = value;
}
}
/// <internalonly/>
/// <devdoc>
/// <para>Gets a value indicating whether this converter
/// can convert an object in the given source type to an enumeration object using
/// the specified context.</para>
/// </devdoc>
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
if (sourceType == typeof(string) || sourceType == typeof(Enum[])) {
return true;
}
return base.CanConvertFrom(context, sourceType);
}
/// <devdoc>
/// <para>Gets a value indicating whether this converter can
/// convert an object to the given destination type using the context.</para>
/// </devdoc>
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
if (destinationType == typeof(InstanceDescriptor) || destinationType == typeof(Enum[])) {
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <devdoc>
/// <para>Gets an <see cref='System.Collections.IComparer'/>
/// interface that can
/// be used to sort the values of the enumerator.</para>
/// </devdoc>
protected virtual IComparer Comparer {
get {
return InvariantComparer.Default;
}
}
/// <internalonly/>
/// <devdoc>
/// <para>Converts the specified value object to an enumeration object.</para>
/// </devdoc>
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
if (value is string) {
try {
string strValue = (string)value;
if (strValue.IndexOf(',') != -1) {
long convertedValue = 0;
string[] values = strValue.Split(new char[] {','});
foreach(string v in values) {
convertedValue |= Convert.ToInt64((Enum)Enum.Parse(type, v, true), culture);
}
return Enum.ToObject(type, convertedValue);
}
else {
return Enum.Parse(type, strValue, true);
}
}
catch (Exception e) {
throw new FormatException(SR.GetString(SR.ConvertInvalidPrimitive, (string)value, type.Name), e);
}
}
else if (value is Enum[]) {
long finalValue = 0;
foreach(Enum e in (Enum[])value) {
finalValue |= Convert.ToInt64(e, culture);
}
return Enum.ToObject(type, finalValue);
}
return base.ConvertFrom(context, culture, value);
}
/// <internalonly/>
/// <devdoc>
/// <para>Converts the given
/// value object to the
/// specified destination type.</para>
/// </devdoc>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1803:AvoidCostlyCallsWherePossible")] // Keep call to Enum.IsDefined
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
if (destinationType == null) {
throw new ArgumentNullException("destinationType");
}
if (destinationType == typeof(string) && value != null) {
// Raise an argument exception if the value isn't defined and if
// the enum isn't a flags style.
//
Type underlyingType = Enum.GetUnderlyingType(type);
if (value is IConvertible && value.GetType() != underlyingType) {
value = ((IConvertible)value).ToType(underlyingType, culture);
}
if (!type.IsDefined(typeof(FlagsAttribute), false) && !Enum.IsDefined(type, value)) {
throw new ArgumentException(SR.GetString(SR.EnumConverterInvalidValue, value.ToString(), type.Name));
}
return Enum.Format(type, value, "G");
}
if (destinationType == typeof(InstanceDescriptor) && value != null) {
string enumName = ConvertToInvariantString(context, value);
if (type.IsDefined(typeof(FlagsAttribute), false) && enumName.IndexOf(',') != -1) {
// This is a flags enum, and there is no one flag
// that covers the value. Instead, convert the
// value to the underlying type and invoke
// a ToObject call on enum.
//
Type underlyingType = Enum.GetUnderlyingType(type);
if (value is IConvertible) {
object convertedValue = ((IConvertible)value).ToType(underlyingType, culture);
MethodInfo method = typeof(Enum).GetMethod("ToObject", new Type[] {typeof(Type), underlyingType});
if (method != null) {
return new InstanceDescriptor(method, new object[] {type, convertedValue});
}
}
}
else {
FieldInfo info = type.GetField(enumName);
if (info != null) {
return new InstanceDescriptor(info, null);
}
}
}
if (destinationType == typeof(Enum[]) && value != null) {
if (type.IsDefined(typeof(FlagsAttribute), false)) {
List<Enum> flagValues = new List<Enum>();
Array objValues = Enum.GetValues(type);
long[] ulValues = new long[objValues.Length];
for(int idx = 0; idx < objValues.Length; idx++) {
ulValues[idx] = Convert.ToInt64((Enum)objValues.GetValue(idx), culture);
}
long longValue = Convert.ToInt64((Enum)value, culture);
bool valueFound = true;
while(valueFound) {
valueFound = false;
foreach(long ul in ulValues) {
if ((ul != 0 && (ul & longValue) == ul) || ul == longValue) {
flagValues.Add((Enum)Enum.ToObject(type, ul));
valueFound = true;
longValue &= ~ul;
break;
}
}
if (longValue == 0) {
break;
}
}
if (!valueFound && longValue != 0) {
flagValues.Add((Enum)Enum.ToObject(type, longValue));
}
return flagValues.ToArray();
}
else {
return new Enum[] {(Enum)Enum.ToObject(type, value)};
}
}
return base.ConvertTo(context, culture, value, destinationType);
}
/// <internalonly/>
/// <devdoc>
/// <para>Gets a collection of standard values for the data type this validator is
/// designed for.</para>
/// </devdoc>
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
if (values == null) {
// We need to get the enum values in this rather round-about way so we can filter
// out fields marked Browsable(false). Note that if multiple fields have the same value,
// the behavior is undefined, since what we return are just enum values, not names.
Type reflectType = TypeDescriptor.GetReflectionType(type);
if (reflectType == null) {
reflectType = type;
}
FieldInfo[] fields = reflectType.GetFields(BindingFlags.Public | BindingFlags.Static);
ArrayList objValues = null;
if (fields != null && fields.Length > 0) {
objValues = new ArrayList(fields.Length);
}
if (objValues != null) {
foreach (FieldInfo field in fields) {
BrowsableAttribute browsableAttr = null;
foreach (Attribute attr in field.GetCustomAttributes(typeof(BrowsableAttribute), false)) {
browsableAttr = attr as BrowsableAttribute;
}
if (browsableAttr == null || browsableAttr.Browsable) {
object value = null;
try {
if (field.Name != null) {
value = Enum.Parse(type, field.Name);
}
}
catch (ArgumentException) {
// Hmm, for some reason, the parse threw. Let us ignore this value.
}
if (value != null) {
objValues.Add(value);
}
}
}
IComparer comparer = Comparer;
if (comparer != null) {
objValues.Sort(comparer);
}
}
Array arr = (objValues != null) ? objValues.ToArray() : null;
values = new StandardValuesCollection(arr);
}
return values;
}
/// <internalonly/>
/// <devdoc>
/// <para>Gets a value indicating whether the list of standard values returned from
/// <see cref='System.ComponentModel.TypeConverter.GetStandardValues'/>
/// is an exclusive list using the specified context.</para>
/// </devdoc>
public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) {
return !type.IsDefined(typeof(FlagsAttribute), false);
}
/// <internalonly/>
/// <devdoc>
/// <para>Gets a value indicating
/// whether this object
/// supports a standard set of values that can be picked
/// from a list using the specified context.</para>
/// </devdoc>
public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
return true;
}
/// <internalonly/>
/// <devdoc>
/// <para>Gets a value indicating whether the given object value is valid for this type.</para>
/// </devdoc>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1803:AvoidCostlyCallsWherePossible")] // Keep call to Enum.IsDefined
public override bool IsValid(ITypeDescriptorContext context, object value) {
return Enum.IsDefined(type, value);
}
}
}
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