source: trunk/sources/HeuristicLab.Core.Views/3.3/ObjectViewBase.cs @ 2655

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2008 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 System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Xml;
using System.Windows.Forms;
using HeuristicLab.MainForm.WindowsForms;

namespace HeuristicLab.Core.Views {
  /// <summary>
  /// Base class for all visual representations.
  /// </summary>
  public partial class ObjectViewBase : ViewBase, IObjectView {
    private object obj;
    /// <summary>
    /// Gets or sets the item to represent visually.
    /// </summary>
    /// <remarks>Calls <see cref="OnItemChanged"/>, <see cref="Refresh"/>, 
    /// <see cref="RemoveItemEvents"/> (if the current item is not null) and 
    /// <see cref="AddItemEvents"/> (if the new item is not null) in the setter.</remarks>
    public object Object {
      get { return obj; }
      protected set {
        if (InvokeRequired) {
          Invoke(new Action<object>(delegate(object o) { Object = o; }), value);
        } else {
          if (value != obj) {
            if (obj != null)
              DeregisterObjectEvents();
            obj = value;
            OnObjectChanged();
            if (obj != null)
              RegisterObjectEvents();
          }
        }
      }
    }

    /// <summary>
    /// Initializes a new instance of <see cref="ViewBase"/> with the caption "View".
    /// </summary>
    public ObjectViewBase() {
      InitializeComponent();
      Caption = "View";
    }

    /// <summary>
    /// Removes the eventhandlers from the current instance.
    /// </summary>
    protected virtual void DeregisterObjectEvents() { }
    /// <summary>
    /// Adds eventhandlers to the current instance.
    /// </summary>
    protected virtual void RegisterObjectEvents() { }

    /// <summary>
    /// Occurs when the current item was changed.
    /// </summary>
    public event EventHandler ObjectChanged;
    /// <summary>
    /// Fires a new <c>ItemChanged</c> event.
    /// </summary>
    protected virtual void OnObjectChanged() {
      Caption = "View";
      if (ObjectChanged != null)
        ObjectChanged(this, new EventArgs());
    }

    /// <summary>
    /// Asynchron call of GUI updating.
    /// </summary>
    /// <param name="method">The delegate to invoke.</param>
    protected new void Invoke(Delegate method) {
      // enforce context switch to improve GUI response time
      System.Threading.Thread.Sleep(0);

      // prevent blocking of worker thread in Invoke, if the control is disposed
      IAsyncResult result = BeginInvoke(method);
      while ((!result.AsyncWaitHandle.WaitOne(100, false)) && (!IsDisposed)) { }
      if (!IsDisposed) EndInvoke(result);
    }
    /// <summary>
    /// Asynchron call of GUI updating.
    /// </summary>
    /// <param name="method">The delegate to invoke.</param>
    /// <param name="args">The invoke arguments.</param>
    protected new void Invoke(Delegate method, params object[] args) {
      // enforce context switch to improve GUI response time
      System.Threading.Thread.Sleep(0);

      // prevent blocking of worker thread in Invoke, if the control is disposed
      IAsyncResult result = BeginInvoke(method, args);
      while ((!result.AsyncWaitHandle.WaitOne(100, false)) && (!IsDisposed)) { }
      if (!IsDisposed) EndInvoke(result);
    }
  }
}