source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/ViewportConstraints/ConstraintCollection.cs @ 13847

using System.Linq;
using System.Windows;
using Microsoft.Research.DynamicDataDisplay;
using Microsoft.Research.DynamicDataDisplay.Common;
using Microsoft.Research.DynamicDataDisplay.Common.Auxiliary;
using System;
using System.Collections.Specialized;

namespace Microsoft.Research.DynamicDataDisplay.ViewportConstraints
{
  /// <summary>
  /// Represents a collection of <see cref="ViewportConstraint"/>s.
  /// <remarks>
  /// ViewportConstraint that is being added should not be null.
  /// </remarks>
  /// </summary>
  public sealed class ConstraintCollection : D3Collection<ViewportConstraint>
  {
    private readonly Viewport2D viewport;
    internal ConstraintCollection(Viewport2D viewport)
    {
      if (viewport == null)
        throw new ArgumentNullException("viewport");

      this.viewport = viewport;
    }

    protected override void OnItemAdding(ViewportConstraint item)
    {
      if (item == null)
        throw new ArgumentNullException("item");
    }

    protected override void OnItemAdded(ViewportConstraint item)
    {
      item.Changed += OnItemChanged;
      ISupportAttachToViewport attachable = item as ISupportAttachToViewport;
      if (attachable != null)
      {
        attachable.Attach(viewport);
      }
    }

    private void OnItemChanged(object sender, EventArgs e)
    {
      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    }

    protected override void OnItemRemoving(ViewportConstraint item)
    {
      ISupportAttachToViewport attachable = item as ISupportAttachToViewport;
      if (attachable != null)
      {
        attachable.Detach(viewport);
      }
      item.Changed -= OnItemChanged;
    }

    internal DataRect Apply(DataRect oldVisible, DataRect newVisible, Viewport2D viewport)
    {
      DataRect res = newVisible;
      foreach (var constraint in this)
      {
        res = constraint.Apply(oldVisible, res, viewport);
      }
      return res;
    }
  }
}