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

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

namespace System.Windows.Data{

  class EnumerableCollectionView : ICollectionView, INotifyPropertyChanged, IDeferRefresh {

    ObservableCollection<object> clonedCollection;
    StandardCollectionView view;

    public event EventHandler CurrentChanged;
    public event CurrentChangingEventHandler CurrentChanging;
    public event NotifyCollectionChangedEventHandler CollectionChanged;
    public event PropertyChangedEventHandler PropertyChanged;
    
    public bool CanFilter {
      get { return view.CanFilter; }
    }

    public bool CanGroup {
      get { return view.CanGroup; }
    }

    public bool CanSort {
      get { return view.CanSort; }
    }

    public System.Globalization.CultureInfo Culture {
      get { return view.Culture; }
      set { view.Culture = value; }
    }

    public object CurrentItem {
      get { return view.CurrentItem; }
    }

    public int CurrentPosition {
      get { return view.CurrentPosition; }
    }

    int IDeferRefresh.DeferLevel {
      get { return ((IDeferRefresh) view).DeferLevel; }
      set { ((IDeferRefresh) view).DeferLevel = value; }
    }

    public Predicate<object> Filter {
      get { return view.Filter; }
      set { view.Filter = value; }
    }

    public ObservableCollection<GroupDescription> GroupDescriptions {
      get { return view.GroupDescriptions; }
    }

    public ReadOnlyObservableCollection<object> Groups {
      get { return view.Groups; }
    }

    public bool IsCurrentAfterLast {
      get { return view.IsCurrentAfterLast; }
    }

    public bool IsCurrentBeforeFirst {
      get { return view.IsCurrentBeforeFirst; }
    }

    public bool IsEmpty {
      get { return view.IsEmpty; }
    }

    public SortDescriptionCollection SortDescriptions {
      get { return view.SortDescriptions; }
    }

    public IEnumerable SourceCollection {
      get; private set;
    }

    public EnumerableCollectionView (IEnumerable collection)
    {
      SourceCollection = collection;

      clonedCollection = new ObservableCollection<object> (collection.Cast <object> ());
      view = new StandardCollectionView (clonedCollection);

      var c = collection as INotifyCollectionChanged;
      if (c != null)
        c.CollectionChanged += HandleCollectionChanged;

      view.CollectionChanged += (o, e) => {
        var h = CollectionChanged;
        if (h != null)
          h (this, e);
      };
      view.CurrentChanged += (o, e) => {
        var h = CurrentChanged;
        if (h != null)
          h (this, e);
      };
      view.CurrentChanging += (o, e) => {
        var h = CurrentChanging;
        if (h != null)
          h (this, e);
      };
      view.PropertyChanged += (o, e) => {
        var h = PropertyChanged;
        if (h != null)
          h (this, e);
      };
    }

    void HandleCollectionChanged (object sender, NotifyCollectionChangedEventArgs e)
    {
      switch (e.Action) {
      case NotifyCollectionChangedAction.Add:
        for (int i = 0; i < e.NewItems.Count; i++)
          clonedCollection.Insert (e.NewStartingIndex + i, e.NewItems [i]);
        break;
      case NotifyCollectionChangedAction.Remove:
        for (int i = e.OldItems.Count; i > 0; i--)
          clonedCollection.RemoveAt (e.OldStartingIndex);
        break;

      case NotifyCollectionChangedAction.Replace:
        for (int i = 0; i < e.OldItems.Count; i++)
          clonedCollection[e.OldStartingIndex + i] = e.NewItems [i];
        break;
      case NotifyCollectionChangedAction.Reset:
        clonedCollection.Clear ();
        foreach (var v in SourceCollection)
          clonedCollection.Add (v);
        break;
      default:
        throw new NotSupportedException ();
      }
    }

    public bool Contains (object item)
    {
      return view.Contains (item);
    }

    public IDisposable DeferRefresh ()
    {
      return view.DeferRefresh ();
    }

    public bool MoveCurrentTo (object item)
    {
      return view.MoveCurrentTo (item);
    }

    public bool MoveCurrentToFirst ()
    {
      return view.MoveCurrentToFirst ();
    }

    public bool MoveCurrentToLast ()
    {
      return view.MoveCurrentToLast ();
    }

    public bool MoveCurrentToNext ()
    {
      return view.MoveCurrentToNext ();
    }

    public bool MoveCurrentToPosition (int position)
    {
      return view.MoveCurrentToPosition (position);
    }

    public bool MoveCurrentToPrevious ()
    {
      return view.MoveCurrentToPrevious ();
    }

    public void Refresh ()
    {
      view.Refresh ();
    }

    public IEnumerator GetEnumerator ()
    {
      return view.GetEnumerator ();
    }
  }
}