source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Common/ObservableCollectionWrapper.cs @ 13808

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.Specialized;
using System.Collections.ObjectModel;

namespace Microsoft.Research.DynamicDataDisplay.Common
{
  public class ObservableCollectionWrapper<T> : INotifyCollectionChanged, IList<T>
  {
    public ObservableCollectionWrapper() : this(new ObservableCollection<T>()) { }

    private readonly ObservableCollection<T> collection;
    public ObservableCollectionWrapper(ObservableCollection<T> collection)
    {
      if (collection == null)
        throw new ArgumentNullException("collection");

      this.collection = collection;
      collection.CollectionChanged += new NotifyCollectionChangedEventHandler(collection_CollectionChanged);
    }

    private int attemptsToRaiseChanged = 0;
    private bool raiseEvents = true;

    public bool RaisingEvents
    {
      get { return raiseEvents; }
    }

    private void collection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
      attemptsToRaiseChanged++;
      if (raiseEvents)
      {
        CollectionChanged.Raise(this, e);
      }
    }

    #region Update methods

    public void BeginUpdate()
    {
      attemptsToRaiseChanged = 0;
      raiseEvents = false;
    }
    public void EndUpdate()
    {
      raiseEvents = true;
      if (attemptsToRaiseChanged > 0)
        CollectionChanged.Raise(this);
    }

    public IDisposable BlockEvents()
    {
      return new EventBlocker<T>(this);
    }

    private sealed class EventBlocker<TT> : IDisposable
    {
      private readonly ObservableCollectionWrapper<TT> collection;
      public EventBlocker(ObservableCollectionWrapper<TT> collection)
      {
        this.collection = collection;
        collection.BeginUpdate();
      }

      #region IDisposable Members

      public void Dispose()
      {
        collection.EndUpdate();
      }

      #endregion
    }

    #endregion // end of Update methods

    #region IList<T> Members

    public int IndexOf(T item)
    {
      return collection.IndexOf(item);
    }

    public void Insert(int index, T item)
    {
      collection.Insert(index, item);
    }

    public void RemoveAt(int index)
    {
      collection.RemoveAt(index);
    }

    public T this[int index]
    {
      get
      {
        return collection[index];
      }
      set
      {
        collection[index] = value;
      }
    }

    #endregion

    #region ICollection<T> Members

    public void Add(T item)
    {
      collection.Add(item);
    }

    public void Clear()
    {
      collection.Clear();
    }

    public bool Contains(T item)
    {
      return collection.Contains(item);
    }

    public void CopyTo(T[] array, int arrayIndex)
    {
      collection.CopyTo(array, arrayIndex);
    }

    public int Count
    {
      get { return collection.Count; }
    }

    public bool IsReadOnly
    {
      get { throw new NotImplementedException(); }
    }

    public bool Remove(T item)
    {
      return collection.Remove(item);
    }

    #endregion

    #region IEnumerable<T> Members

    public IEnumerator<T> GetEnumerator()
    {
      return collection.GetEnumerator();
    }

    #endregion

    #region IEnumerable Members

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }

    #endregion

    #region INotifyCollectionChanged Members

    public event NotifyCollectionChangedEventHandler CollectionChanged;

    #endregion
  }
}