/// <summary>
/// Returns true, iff this AttributeSource contains the passed-in attribute type.
/// </summary>
public virtual bool HasAttribute(Type attrType)
{
if (attrType == null)
{
throw new ArgumentNullException("attrType");
}
return(attributes.Contains(attrType));
}
/// <summary>
/// <b>Expert:</b> Adds a custom AttributeImpl instance with one or more Attribute interfaces.
/// <p><font color="red"><b>Please note:</b> It is not guaranteed, that <c>attr</c> is added to
/// the <c>AttributeSource</c>, because the provided attributes may already exist.
/// You should always retrieve the wanted attributes using <see cref="GetAttribute{T}"/> after adding
/// with this method and cast to your class.
/// The recommended way to use custom implementations is using an <see cref="AttributeFactory"/>
/// </font></p>
/// </summary>
public virtual void AddAttributeImpl(Attribute attr)
{
Type attrType = attr.GetType();
if (attributeImpls.Contains(attrType))
{
return;
}
LinkedList <WeakReference> foundInterfaces;
lock (knownImplClasses)
{
foundInterfaces = knownImplClasses[attrType];
if (foundInterfaces == null)
{
// we have a strong reference to the class instance holding all interfaces in the list (parameter "attr"),
// so all WeakReferences are never evicted by GC
knownImplClasses.Add(attrType, foundInterfaces = new LinkedList <WeakReference>());
// find all interfaces that this attribute instance implements
// and that extend the Attribute interface
var type = attrType;
do
{
var interfaces = type.GetInterfaces();
foreach (var curInterface in interfaces)
{
if (curInterface != typeof(IAttribute) && typeof(IAttribute).IsAssignableFrom(curInterface))
{
foundInterfaces.AddLast(new WeakReference(curInterface));
}
}
type = type.BaseType;
}while (type != null);
}
}
// add all interfaces of this AttributeImpl to the maps
foreach (var curInterfaceRef in foundInterfaces)
{
Type curInterface = (Type)curInterfaceRef.Target;
System.Diagnostics.Debug.Assert(curInterface != null,
"We have a strong reference on the class holding the interfaces, so they should never get evicted");
// Attribute is a superclass of this interface
if (!attributes.ContainsKey(curInterface))
{
// invalidate state to force recomputation in captureState()
this.currentState[0] = null;
attributes.Add(new AttributeImplItem(curInterface, attr));
if (!attributeImpls.ContainsKey(attrType))
{
attributeImpls.Add(new AttributeImplItem(attrType, attr));
}
}
}
}
/// <summary>
/// <b>Expert:</b> Adds a custom AttributeImpl instance with one or more Attribute interfaces.
/// <p><font color="red"><b>Please note:</b> It is not guaranteed, that <c>att</c> is added to
/// the <c>AttributeSource</c>, because the provided attributes may already exist.
/// You should always retrieve the wanted attributes using <see cref="GetAttribute{T}"/> after adding
/// with this method and cast to your class.
/// The recommended way to use custom implementations is using an <see cref="AttributeFactory"/>
/// </font></p>
/// </summary>
public virtual void AddAttributeImpl(Attribute att)
{
System.Type clazz = att.GetType();
if (attributeImpls.Contains(clazz))
{
return;
}
System.Collections.Generic.LinkedList <WeakReference> foundInterfaces;
lock (knownImplClasses)
{
foundInterfaces = knownImplClasses[clazz];
if (foundInterfaces == null)
{
// we have a strong reference to the class instance holding all interfaces in the list (parameter "att"),
// so all WeakReferences are never evicted by GC
knownImplClasses.Add(clazz, foundInterfaces = new LinkedList <WeakReference>());
// find all interfaces that this attribute instance implements
// and that extend the Attribute interface
System.Type actClazz = clazz;
do
{
System.Type[] interfaces = actClazz.GetInterfaces();
for (int i = 0; i < interfaces.Length; i++)
{
System.Type curInterface = interfaces[i];
if (curInterface != typeof(IAttribute) && typeof(IAttribute).IsAssignableFrom(curInterface))
{
foundInterfaces.AddLast(new WeakReference(curInterface));
}
}
actClazz = actClazz.BaseType;
}while (actClazz != null);
}
}
// add all interfaces of this AttributeImpl to the maps
foreach (var curInterfaceRef in foundInterfaces)
{
System.Type curInterface = (System.Type)curInterfaceRef.Target;
System.Diagnostics.Debug.Assert(curInterface != null,
"We have a strong reference on the class holding the interfaces, so they should never get evicted");
// Attribute is a superclass of this interface
if (!attributes.ContainsKey(curInterface))
{
// invalidate state to force recomputation in captureState()
this.currentState[0] = null;
attributes.Add(new AttributeImplItem(curInterface, att));
if (!attributeImpls.ContainsKey(clazz))
{
attributeImpls.Add(new AttributeImplItem(clazz, att));
}
}
}
}