//
// PropertyPathNode.cs
//
// Contact:
// Moonlight List (moonlight-list@lists.ximian.com)
//
// Copyright 2010 Novell, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
using System.ComponentModel;
using System.Reflection;
namespace System.Windows.Data{
abstract class PropertyPathNode : IPropertyPathNode {
public event EventHandler ValueChanged;
object value;
public DependencyProperty DependencyProperty {
get; protected set;
}
public virtual bool IsBroken {
get {
// If any node in the middle of the chain has a null source,
// then the final value cannot be retrieved so the chain is broken
return Source == null || (PropertyInfo == null && DependencyProperty == null);
}
}
public IPropertyPathNode Next {
get; set;
}
public PropertyInfo PropertyInfo {
get; protected set;
}
public object Source {
get; set;
}
public object Value {
get { return value; }
protected set {
if (!object.Equals (value, this.value)) {
this.value = value;
var h = ValueChanged;
if (h != null && this.Next == null)
h (this, EventArgs.Empty);
}
}
}
public Type ValueType {
get; protected set;
}
protected PropertyPathNode ()
{
}
protected virtual void OnSourceChanged (object oldSource, object newSource)
{
}
protected virtual void OnSourcePropertyChanged (object o, PropertyChangedEventArgs e)
{
}
public abstract void SetValue (object value);
public void SetSource (object source)
{
if (Source != source) {
var oldSource = Source;
if (Source is INotifyPropertyChanged)
((INotifyPropertyChanged) Source).PropertyChanged -= OnSourcePropertyChanged;
Source = source;
if (Source is INotifyPropertyChanged)
((INotifyPropertyChanged) Source).PropertyChanged += OnSourcePropertyChanged;
OnSourceChanged (oldSource, Source);
UpdateValue ();
if (Next != null)
Next.SetSource (Value);
}
}
public abstract void UpdateValue ();
}
}
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