|
//------------------------------------------------------------------------------
// <copyright file="ExtendedPropertyDescriptor.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
*/
namespace System.ComponentModel {
using Microsoft.Win32;
using System;
using System.Collections;
using System.ComponentModel.Design;
using System.Diagnostics;
using System.Security.Permissions;
/// <internalonly/>
/// <devdoc>
/// <para>
/// This class wraps an PropertyDescriptor with something that looks like a property. It
/// allows you to treat extended properties the same as regular properties.
/// </para>
/// </devdoc>
[HostProtection(SharedState = true)]
internal sealed class ExtendedPropertyDescriptor : PropertyDescriptor {
private readonly ReflectPropertyDescriptor extenderInfo; // the extender property
private readonly IExtenderProvider provider; // the guy providing it
/// <devdoc>
/// Creates a new extended property info. Callers can then treat this as
/// a standard property.
/// </devdoc>
public ExtendedPropertyDescriptor(ReflectPropertyDescriptor extenderInfo, Type receiverType, IExtenderProvider provider, Attribute[] attributes)
: base(extenderInfo, attributes) {
Debug.Assert(extenderInfo != null, "ExtendedPropertyDescriptor must have extenderInfo");
Debug.Assert(provider != null, "ExtendedPropertyDescriptor must have provider");
ArrayList attrList = new ArrayList(AttributeArray);
attrList.Add(ExtenderProvidedPropertyAttribute.Create(extenderInfo, receiverType, provider));
if (extenderInfo.IsReadOnly) {
attrList.Add(ReadOnlyAttribute.Yes);
}
Attribute[] temp = new Attribute[attrList.Count];
attrList.CopyTo(temp, 0);
AttributeArray = temp;
this.extenderInfo = extenderInfo;
this.provider = provider;
}
public ExtendedPropertyDescriptor(PropertyDescriptor extender, Attribute[] attributes) : base(extender, attributes) {
Debug.Assert(extender != null, "The original PropertyDescriptor must be non-null");
ExtenderProvidedPropertyAttribute attr = extender.Attributes[typeof(ExtenderProvidedPropertyAttribute)] as ExtenderProvidedPropertyAttribute;
Debug.Assert(attr != null, "The original PropertyDescriptor does not have an ExtenderProvidedPropertyAttribute");
ReflectPropertyDescriptor reflectDesc = attr.ExtenderProperty as ReflectPropertyDescriptor;
Debug.Assert(reflectDesc != null, "The original PropertyDescriptor has an invalid ExtenderProperty");
this.extenderInfo = reflectDesc;
this.provider = attr.Provider;
}
/// <devdoc>
/// Determines if the the component will allow its value to be reset.
/// </devdoc>
public override bool CanResetValue(object comp) {
return extenderInfo.ExtenderCanResetValue(provider, comp);
}
/// <devdoc>
/// Retrieves the type of the component this PropertyDescriptor is bound to.
/// </devdoc>
public override Type ComponentType {
get {
return extenderInfo.ComponentType;
}
}
/// <devdoc>
/// Determines if the property can be written to.
/// </devdoc>
public override bool IsReadOnly {
get {
return Attributes[typeof(ReadOnlyAttribute)].Equals(ReadOnlyAttribute.Yes);
}
}
/// <devdoc>
/// Retrieves the data type of the property.
/// </devdoc>
public override Type PropertyType {
get {
return extenderInfo.ExtenderGetType(provider);
}
}
/// <devdoc>
/// Retrieves the display name of the property. This is the name that will
/// be displayed in a properties window. This will be the same as the property
/// name for most properties.
/// </devdoc>
public override string DisplayName {
get {
string name = base.DisplayName;
DisplayNameAttribute displayNameAttr = Attributes[typeof(DisplayNameAttribute)] as DisplayNameAttribute;
if (displayNameAttr == null || displayNameAttr.IsDefaultAttribute()) {
ISite site = GetSite(provider);
if (site != null) {
string providerName = site.Name;
if (providerName != null && providerName.Length > 0) {
name = SR.GetString(SR.MetaExtenderName, name, providerName);
}
}
}
return name;
}
}
/// <devdoc>
/// Retrieves the value of the property for the given component. This will
/// throw an exception if the component does not have this property.
/// </devdoc>
public override object GetValue(object comp) {
return extenderInfo.ExtenderGetValue(provider, comp);
}
/// <devdoc>
/// Resets the value of this property on comp to the default value.
/// </devdoc>
public override void ResetValue(object comp) {
extenderInfo.ExtenderResetValue(provider, comp, this);
}
/// <devdoc>
/// Sets the value of this property on the given component.
/// </devdoc>
public override void SetValue(object component, object value) {
extenderInfo.ExtenderSetValue(provider, component, value, this);
}
/// <devdoc>
/// Determines if this property should be persisted. A property is
/// to be persisted if it is marked as persistable through a
/// PersistableAttribute, and if the property contains something other
/// than the default value. Note, however, that this method will
/// return true for design time properties as well, so callers
/// should also check to see if a property is design time only before
/// persisting to runtime storage.
/// </devdoc>
public override bool ShouldSerializeValue(object comp) {
return extenderInfo.ExtenderShouldSerializeValue(provider, comp);
}
/*
The following code has been removed to fix FXCOP violations. The code
is left here incase it needs to be resurrected in the future.
/// <devdoc>
/// Creates a new extended property info. Callers can then treat this as
/// a standard property.
/// </devdoc>
public ExtendedPropertyDescriptor(ReflectPropertyDescriptor extenderInfo, Type receiverType, IExtenderProvider provider) : this(extenderInfo, receiverType, provider, null) {
}
/// <devdoc>
/// Retrieves the object that is providing this extending property.
/// </devdoc>
public IExtenderProvider Provider {
get {
return provider;
}
}
*/
}
}
|