source: branches/OptimizationNetworks/HeuristicLab.Optimization.Networks/3.3/InputPort.cs @ 11452

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using System;
using System.Drawing;

namespace HeuristicLab.Optimization.Networks {
  [Item("InputPort", "An asynchronous input port of an optimization network node.")]
  [StorableClass]
  public class InputPort<T> : ValuePort<T>, IInputPort<T> where T : class, IItem {
    public static new Image StaticItemImage {
      get { return HeuristicLab.Common.Resources.VSImageLibrary.ArrowDown; }
    }

    [Storable]
    private IOutputPort<T> outputPort;
    public IOutputPort<T> OutputPort {
      get { return outputPort; }
      set {
        if (outputPort != value) {
          DeregisterOutputPortEvents();
          outputPort = value;
          RegisterOutputPortEvents();
          OnOutputPortChanged();
          UpdateValue();
        }
      }
    }
    IOutputPort IInputPort.OutputPort {
      get { return outputPort; }
      set {
        var val = value as IOutputPort<T>;
        if ((value != null) && (val == null))
          throw new InvalidOperationException(
            string.Format("Type mismatch. OutputPort is not a \"{0}\".",
                          typeof(IOutputPort<T>).GetPrettyName())
          );
        OutputPort = val;
      }
    }

    [StorableConstructor]
    protected InputPort(bool deserializing) : base(deserializing) { }
    protected InputPort(InputPort<T> original, Cloner cloner) : base(original, cloner) {
      outputPort = cloner.Clone(original.outputPort);
      RegisterOutputPortEvents();
    }
    public InputPort() : base("InputPort") { }
    public InputPort(string name) : base(name) { }
    public InputPort(string name, string description) : base(name, description) { }

    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      RegisterOutputPortEvents();
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new InputPort<T>(this, cloner);
    }

    protected virtual void UpdateValue() {
      if (OutputPort != null) {
        var value = OutputPort.Value;
        if (value != null)
          value = (T)value.Clone();
        Value = value;
        //DISCUSS: clone value?
        //DISCUSS: switch threads to decouple value propagation and to make communication asynchronous -> should be done in Node?
      }
    }

    public event EventHandler OutputPortChanged;
    protected void OnOutputPortChanged() {
      var handler = OutputPortChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    protected void RegisterOutputPortEvents() {
      if (outputPort != null) {
        outputPort.ValueChanged += OutputPort_ValueChanged;
      }
    }
    protected void DeregisterOutputPortEvents() {
      if (outputPort != null) {
        outputPort.ValueChanged -= OutputPort_ValueChanged;
      }
    }
    protected void OutputPort_ValueChanged(object sender, EventArgs e) {
      UpdateValue();
    }
  }
}