IndexedPropertyPathNode.cs :  » 2.6.4-mono-.net-core » System.Windows » System » Windows » Data » C# / CSharp Open Source

//
// IndexedPropertyPathNode.cs
//
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//
// 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.Collections.Specialized;
using System.Reflection;
using System.ComponentModel;

namespace System.Windows.Data{
  class IndexedPropertyPathNode : PropertyPathNode {
    static readonly PropertyInfo IListIndexer = GetIndexer (true, typeof (IList));

    bool isBroken;
    public override bool IsBroken {
      get {
        return isBroken || base.IsBroken;
      }
    }

    public object Index {
      get; private set;
    }

    public IndexedPropertyPathNode (string index)
    {
      int val;
      if (int.TryParse (index, out val))
        Index = val;
      else
        Index = index;
    }

    void GetIndexer ()
    {
      PropertyInfo = null;
      if (Source != null) {
        PropertyInfo = GetIndexer (Index is int, Source.GetType ());
        if (PropertyInfo == null && Source is IList)
          PropertyInfo = IListIndexer;
      }
    }

    static PropertyInfo GetIndexer (bool allowIntIndexer, Type type)
    {
      PropertyInfo propInfo = null;
      var members = type.GetDefaultMembers ();
      foreach (PropertyInfo member in members) {
        var param = member.GetIndexParameters ();
        if (param.Length == 1) {
          if (allowIntIndexer && param[0].ParameterType == typeof (int)) {
            propInfo = member;
            break;
          } else if (param [0].ParameterType == typeof (string)) {
            propInfo = member;
          }
        }
      }

      return propInfo;
    }

    void OnCollectionChanged (object o, NotifyCollectionChangedEventArgs e)
    {
      UpdateValue ();
      if (Next != null)
        Next.SetSource (Value);
    }

    void OnPropertyChanged (object o, PropertyChangedEventArgs e)
    {
      UpdateValue ();
      if (Next != null)
        Next.SetSource (Value);
    }

    protected override void OnSourceChanged (object oldSource, object newSource)
    {
      base.OnSourceChanged (oldSource, newSource);

      if (oldSource is INotifyCollectionChanged)
        ((INotifyCollectionChanged) oldSource).CollectionChanged -= OnCollectionChanged;
      if (newSource is INotifyCollectionChanged)
        ((INotifyCollectionChanged) newSource).CollectionChanged += OnCollectionChanged;

      if (oldSource is INotifyPropertyChanged)
        ((INotifyPropertyChanged) oldSource).PropertyChanged -= OnPropertyChanged;
      if (newSource is INotifyPropertyChanged)
        ((INotifyPropertyChanged) newSource).PropertyChanged += OnPropertyChanged;
      
      GetIndexer ();
    }

    public override void SetValue (object value)
    {
      if (PropertyInfo != null)
        PropertyInfo.SetValue (Source, value, new object[] { Index });
    }

    public override void UpdateValue ()
    {
      isBroken = true;
      if (PropertyInfo == null) {
        ValueType = null;
        Value = null;
        return;
      }

      try {
        object newVal = PropertyInfo.GetValue (Source, new object [] { Index });
        isBroken = false;
        if (Value != newVal) {
          ValueType = newVal == null ? null : newVal.GetType ();
          Value = newVal;
        }
      } catch {
        ValueType = null;
        Value = null;
      }
    }
  }
}