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namespace System.Windows
{
using System;
/// <summary>
/// This attribute declares that a property is visible when the
/// property owner is a parent of another element. For example,
/// Canvas.Left is only useful on elements parented within the
/// canvas. The class supports two types of tree walks: a shallow
/// walk, the default which requires that the immediate parent be the
/// owner type of the property, and a deep walk, declared by setting
/// IncludeDescendants to true and requires that the owner type be
/// somewhere in the parenting hierarchy.
/// </summary>
[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
public sealed class AttachedPropertyBrowsableForChildrenAttribute : AttachedPropertyBrowsableAttribute
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
/// <summary>
/// Creates a new AttachedPropertyBrowsableForChildrenAttribute.
/// </summary>
public AttachedPropertyBrowsableForChildrenAttribute()
{
}
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
/// <summary>
/// Gets or sets if the property should be browsable for just the
/// immediate children (false) or all children (true).
/// </summary>
public bool IncludeDescendants
{
get
{
return _includeDescendants;
}
set
{
_includeDescendants = value;
}
}
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
/// <summary>
/// Overrides Object.Equals to implement correct equality semantics for this
/// attribute.
/// </summary>
public override bool Equals(object obj)
{
AttachedPropertyBrowsableForChildrenAttribute other = obj as AttachedPropertyBrowsableForChildrenAttribute;
if (other == null) return false;
return _includeDescendants == other._includeDescendants;
}
/// <summary>
/// Overrides Object.GetHashCode to implement correct hashing semantics.
/// </summary>
public override int GetHashCode()
{
return _includeDescendants.GetHashCode();
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
/// <summary>
/// Returns true if the object provided is the immediate logical
/// child (if IncludeDescendants is false) or any logical child
/// (if IncludeDescendants is true).
/// </summary>
internal override bool IsBrowsable(DependencyObject d, DependencyProperty dp)
{
if (d == null) throw new ArgumentNullException("d");
if (dp == null) throw new ArgumentNullException("dp");
DependencyObject walk = d;
Type ownerType = dp.OwnerType;
do
{
walk = FrameworkElement.GetFrameworkParent(walk);
if (walk != null && ownerType.IsInstanceOfType(walk))
{
return true;
}
}
while (_includeDescendants && walk != null);
return false;
}
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
private bool _includeDescendants;
}
}
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