source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/DataSources/OneDimensional/EmptyDataSource.cs @ 13467

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Diagnostics.CodeAnalysis;

namespace Microsoft.Research.DynamicDataDisplay.DataSources
{
  /// <summary>
  /// Empty data source - for testing purposes, represents data source with 0 points inside.
  /// </summary>
  public class EmptyDataSource : IPointDataSource
  {
    #region IPointDataSource Members

    public IPointEnumerator GetEnumerator(DependencyObject context)
    {
      return new EmptyPointEnumerator();
    }

    [SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
    private void RaiseDataChanged()
    {
      if (DataChanged != null)
      {
        DataChanged(this, EventArgs.Empty);
      }
    }

    public event EventHandler DataChanged;

    #endregion

    private sealed class EmptyPointEnumerator : IPointEnumerator
    {
      public bool MoveNext()
      {
        return false;
      }

      public void GetCurrent(ref Point p)
      {
        // nothing to do
      }

      public void ApplyMappings(DependencyObject target)
      {
        // nothing to do
      }

      public void Dispose() { }
    }
  }
}