MenuTreeView.cs :  » Business-Application » DC » DCSharp » GUI » C# / CSharp Open Source

/*
 * Copyright (C) 2006-2007 Eskil Bylund
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

using System;
using System.Collections;

using Gtk;

namespace DCSharp.GUI{
  public delegate void PopulatePopupHandler(object obj,
    PopulatePopupArgs args);
  
  public class PopulatePopupArgs : EventArgs
  {
    public PopulatePopupArgs(Menu menu)
    {
      this.menu = menu;
    }
    
    private Menu menu;
    
    public Menu Menu
    {
      get
      {
        return menu;
      }
    }
  }
  
  public class MenuTreeView : TreeView
  {
    public event PopulatePopupHandler PopulatePopup;
    
    public MenuTreeView(TreeModel model) : base(model)
    {
      uim = new UIManager();
    }
    
    public MenuTreeView() : base()
    {
      uim = new UIManager();
    }
    
    #region Properties
    
    private UIManager uim;
    
    public UIManager Uim
    {
      get
      {
        return uim;
      }
    }
    
    #endregion
    
    #region Methods
    
    protected override bool OnButtonPressEvent(Gdk.EventButton evnt)
    {
      if (evnt.Type == Gdk.EventType.ButtonPress && evnt.Button == 3)
      {
        TreePath path;
        if (GetPathAtPos((int)evnt.X, (int)evnt.Y, out path))
        {
          // TreePath.Equals is broken. Proper implementation:
          Predicate<TreePath> pathEquals = delegate(TreePath p)
          {
            return p.Compare(path) == 0;
          };
          
          // Selection handling
          // TODO: Proper selection when the shift key is pressed.
          TreePath[] selectedPaths = Selection.GetSelectedRows();
          if (!Array.Exists(selectedPaths, pathEquals))
          {
            // Path not selected
            if ((evnt.State & Gdk.ModifierType.ControlMask) == 0)
            {
              Selection.UnselectAll();
            }
            Selection.SelectPath(path);
          }
          
          DoMenuPopup(evnt);
          return true;
        }
      }
      return base.OnButtonPressEvent(evnt);
    }
    
    protected override bool OnPopupMenu()
    {
      DoMenuPopup(null);
      return true;
    }
    
    protected void DoMenuPopup(Gdk.EventButton evnt)
    {
      Menu menu = uim.GetWidget("/Popup") as Menu;
      if (menu == null)
      {
        menu = new Menu();
      }
      
      OnPopulatePopup(menu);
      
      if (menu.Children.Length > 0)
      {
        // TODO: Position the menu when the event is null.
        uint button = evnt != null ? evnt.Button : 0;
        uint eventTime = evnt != null ? evnt.Time : Global.CurrentEventTime;
        
        menu.Popup(null, null, null, button, eventTime);
      }
    }
    
    protected virtual void OnPopulatePopup(Menu menu)
    {
      if (PopulatePopup != null)
      {
        PopulatePopup(this, new PopulatePopupArgs(menu));
      }
    }
    
    #endregion
  }
}