mcs/class/System.Design/System.ComponentModel.Design/CollectionEditor.cs

   1 //
   2 // System.ComponentModel.Design.CollectionEditor
   3 //
   4 // Authors:
   5 //      Martin Willemoes Hansen (mwh@sysrq.dk)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //      Ivan N. Zlatev (contact@i-nz.net)
   8 //
   9 // (C) 2003 Martin Willemoes Hansen
  10 // (C) 2007 Andreas Nahr
  11 // (C) 2007 Ivan N. Zlatev
  12 // (C) 2008 Novell, Inc
  13 //
  14
  15 //
  16 // Permission is hereby granted, free of charge, to any person obtaining
  17 // a copy of this software and associated documentation files (the
  18 // "Software"), to deal in the Software without restriction, including
  19 // without limitation the rights to use, copy, modify, merge, publish,
  20 // distribute, sublicense, and/or sell copies of the Software, and to
  21 // permit persons to whom the Software is furnished to do so, subject to
  22 // the following conditions:
  23 //
  24 // The above copyright notice and this permission notice shall be
  25 // included in all copies or substantial portions of the Software.
  26 //
  27 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  28 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  29 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  30 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  31 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  32 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  33 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  34 //
  35
  36
  37 using System;
  38 using System.Reflection;
  39 using System.Collections;
  40 using System.ComponentModel;
  41 using System.Drawing.Design;
  42 using System.Windows.Forms;
  43 using System.Windows.Forms.Design;
  44
  45 namespace System.ComponentModel.Design
  46 {
  47         public class CollectionEditor : UITypeEditor
  48         {
  49                 protected abstract class CollectionForm : Form
  50                 {
  51                         private CollectionEditor editor;
  52                         private object editValue;
  53
  54                         public CollectionForm (CollectionEditor editor)
  55                         {
  56                                 this.editor = editor;
  57                         }
  58
  59                         protected Type CollectionItemType
  60                         {
  61                                 get { return editor.CollectionItemType; }
  62                         }
  63
  64                         protected Type CollectionType
  65                         {
  66                                 get { return editor.CollectionType; }
  67                         }
  68
  69                         protected ITypeDescriptorContext Context
  70                         {
  71                                 get { return editor.Context; }
  72                         }
  73
  74                         public object EditValue
  75                         {
  76                                 get { return editValue; }
  77                                 set
  78                                 {
  79                                         editValue = value;
  80                                         OnEditValueChanged ();
  81                                 }
  82                         }
  83
  84                         protected object[] Items
  85                         {
  86                                 get { return editor.GetItems (editValue); }
  87                                 set {
  88                                         if (editValue == null) {
  89                                                 object newEmptyCollection = null;
  90                                                 try {
  91                                                         if (typeof (Array).IsAssignableFrom (CollectionType))
  92                                                                 newEmptyCollection = Array.CreateInstance (CollectionItemType, 0);
  93                                                         else
  94                                                                 newEmptyCollection = Activator.CreateInstance (CollectionType);
  95                                                 } catch {}
  96
  97                                                 object val = editor.SetItems (newEmptyCollection, value);
  98                                                 if (val != newEmptyCollection)
  99                                                         EditValue = val;
 100                                         } else {
 101                                                 object val = editor.SetItems (editValue, value);
 102                                                 if (val != editValue)
 103                                                         EditValue = val;
 104                                         }
 105                                 }
 106                         }
 107
 108                         protected Type[] NewItemTypes
 109                         {
 110                                 get { return editor.NewItemTypes; }
 111                         }
 112
 113                         protected bool CanRemoveInstance (object value)
 114                         {
 115                                 return editor.CanRemoveInstance (value);
 116                         }
 117
 118                         protected virtual bool CanSelectMultipleInstances ()
 119                         {
 120                                 return editor.CanSelectMultipleInstances ();
 121                         }
 122
 123                         protected object CreateInstance (Type itemType)
 124                         {
 125                                 return editor.CreateInstance (itemType);
 126                         }
 127
 128                         protected void DestroyInstance (object instance)
 129                         {
 130                                 editor.DestroyInstance (instance);
 131                         }
 132
 133                         protected virtual void DisplayError (Exception e)
 134                         {
 135                                 MessageBox.Show (e.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Information);
 136                         }
 137
 138                         protected override object GetService (Type serviceType)
 139                         {
 140                                 return editor.GetService (serviceType);
 141                         }
 142
 143                         protected abstract void OnEditValueChanged ();
 144
 145                         protected internal virtual DialogResult ShowEditorDialog (IWindowsFormsEditorService edSvc)
 146                         {
 147                                 return edSvc.ShowDialog (this);
 148                         }
 149                 }
 150
 151                 private class ConcreteCollectionForm : CollectionForm
 152                 {
 153                         internal class ObjectContainerConverter : TypeConverter
 154                         {
 155                                 private class ObjectContainerPropertyDescriptor : TypeConverter.SimplePropertyDescriptor
 156                                 {
 157                                         private AttributeCollection attributes;
 158
 159                                         public ObjectContainerPropertyDescriptor (Type componentType, Type propertyType)
 160                                                 : base (componentType, "Value", propertyType)
 161                                         {
 162                                                 CategoryAttribute cat = new CategoryAttribute (propertyType.Name);
 163                                                 attributes = new AttributeCollection (new Attribute[] { cat });
 164                                         }
 165
 166                                         public override object GetValue (object component)
 167                                         {
 168                                                 ObjectContainer container = (ObjectContainer)component;
 169                                                 return container.Object;
 170                                         }
 171
 172                                         public override void SetValue (object component, object value)
 173                                         {
 174                                                 ObjectContainer container = (ObjectContainer)component;
 175                                                 container.Object = value;
 176                                         }
 177
 178                                         public override AttributeCollection Attributes
 179                                         {
 180                                                 get { return attributes; }
 181                                         }
 182                                 }
 183
 184                                 public override PropertyDescriptorCollection GetProperties (ITypeDescriptorContext context, object value, Attribute[] attributes)
 185                                 {
 186                                         ObjectContainer container = (ObjectContainer)value;
 187                                         ObjectContainerPropertyDescriptor desc = new ObjectContainerPropertyDescriptor (value.GetType (), container.editor.CollectionItemType);
 188                                         PropertyDescriptor[] properties = new PropertyDescriptor[] { desc };
 189                                         PropertyDescriptorCollection pc = new PropertyDescriptorCollection (properties);
 190                                         return pc;
 191                                 }
 192
 193                                 public override bool GetPropertiesSupported (ITypeDescriptorContext context)
 194                                 {
 195                                         return true;
 196                                 }
 197                         }
 198
 199                         [TypeConverter (typeof (ObjectContainerConverter))]
 200                         private class ObjectContainer
 201                         {
 202                                 internal object Object;
 203                                 internal CollectionEditor editor;
 204
 205                                 public ObjectContainer (object obj, CollectionEditor editor)
 206                                 {
 207                                         this.Object = obj;
 208                                         this.editor = editor;
 209                                 }
 210
 211                                 internal string Name {
 212                                         get { return editor.GetDisplayText (Object); }
 213                                 }
 214
 215                                 public override string ToString ()
 216                                 {
 217                                         return Name;
 218                                 }
 219                         }
 220
 221                         private class UpdateableListbox : ListBox
 222                         {
 223                                 public void DoRefreshItem (int index)
 224                                 {
 225                                         base.RefreshItem (index);
 226                                 }
 227                         }
 228
 229                         private CollectionEditor editor;
 230
 231                         private System.Windows.Forms.Label labelMember;
 232                         private System.Windows.Forms.Label labelProperty;
 233                         private UpdateableListbox itemsList;
 234                         private System.Windows.Forms.PropertyGrid itemDisplay;
 235                         private System.Windows.Forms.Button doClose;
 236                         private System.Windows.Forms.Button moveUp;
 237                         private System.Windows.Forms.Button moveDown;
 238                         private System.Windows.Forms.Button doAdd;
 239                         private System.Windows.Forms.Button doRemove;
 240                         private System.Windows.Forms.Button doCancel;
 241                         private System.Windows.Forms.ComboBox addType;
 242
 243                         public ConcreteCollectionForm (CollectionEditor editor)
 244                                 : base (editor)
 245                         {
 246                                 this.editor = editor;
 247
 248                                 this.labelMember = new System.Windows.Forms.Label ();
 249                                 this.labelProperty = new System.Windows.Forms.Label ();
 250                                 this.itemsList = new UpdateableListbox ();
 251                                 this.itemDisplay = new System.Windows.Forms.PropertyGrid ();
 252                                 this.doClose = new System.Windows.Forms.Button ();
 253                                 this.moveUp = new System.Windows.Forms.Button ();
 254                                 this.moveDown = new System.Windows.Forms.Button ();
 255                                 this.doAdd = new System.Windows.Forms.Button ();
 256                                 this.doRemove = new System.Windows.Forms.Button ();
 257                                 this.doCancel = new System.Windows.Forms.Button ();
 258                                 this.addType = new System.Windows.Forms.ComboBox ();
 259                                 this.SuspendLayout ();
 260                                 //
 261                                 // labelMember
 262                                 //
 263                                 this.labelMember.Location = new System.Drawing.Point (12, 9);
 264                                 this.labelMember.Size = new System.Drawing.Size (55, 13);
 265                                 this.labelMember.Text = "Members:";
 266                                 //
 267                                 // labelProperty
 268                                 //
 269                                 this.labelProperty.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
 270                                                         | System.Windows.Forms.AnchorStyles.Right)));
 271                                 this.labelProperty.Location = new System.Drawing.Point (172, 9);
 272                                 this.labelProperty.Size = new System.Drawing.Size (347, 13);
 273                                 this.labelProperty.Text = "Properties:";
 274                                 //
 275                                 // itemsList
 276                                 //
 277                                 this.itemsList.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
 278                                                         | System.Windows.Forms.AnchorStyles.Left)));
 279                                 this.itemsList.HorizontalScrollbar = true;
 280                                 this.itemsList.Location = new System.Drawing.Point (12, 25);
 281                                 this.itemsList.SelectionMode = System.Windows.Forms.SelectionMode.MultiExtended;
 282                                 this.itemsList.Size = new System.Drawing.Size (120, 290);
 283                                 this.itemsList.TabIndex = 0;
 284                                 this.itemsList.SelectedIndexChanged += new System.EventHandler (this.itemsList_SelectedIndexChanged);
 285                                 //
 286                                 // itemDisplay
 287                                 //
 288                                 this.itemDisplay.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
 289                                                         | System.Windows.Forms.AnchorStyles.Left)
 290                                                         | System.Windows.Forms.AnchorStyles.Right)));
 291                                 this.itemDisplay.HelpVisible = false;
 292                                 this.itemDisplay.Location = new System.Drawing.Point (175, 25);
 293                                 this.itemDisplay.Size = new System.Drawing.Size (344, 314);
 294                                 this.itemDisplay.TabIndex = 6;
 295                                 this.itemDisplay.PropertyValueChanged += new System.Windows.Forms.PropertyValueChangedEventHandler (this.itemDisplay_PropertyValueChanged);
 296                                 //
 297                                 // doClose
 298                                 //
 299                                 this.doClose.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
 300                                 this.doClose.Location = new System.Drawing.Point (341, 345);
 301                                 this.doClose.Size = new System.Drawing.Size (86, 26);
 302                                 this.doClose.TabIndex = 7;
 303                                 this.doClose.Text = "OK";
 304                                 this.doClose.Click += new System.EventHandler (this.doClose_Click);
 305                                 //
 306                                 // moveUp
 307                                 //
 308                                 this.moveUp.Location = new System.Drawing.Point (138, 25);
 309                                 this.moveUp.Size = new System.Drawing.Size (31, 28);
 310                                 this.moveUp.TabIndex = 4;
 311                                 this.moveUp.Enabled = false;
 312                                 this.moveUp.Text = "Up";
 313                                 this.moveUp.Click += new System.EventHandler (this.moveUp_Click);
 314                                 //
 315                                 // moveDown
 316                                 //
 317                                 this.moveDown.Location = new System.Drawing.Point (138, 59);
 318                                 this.moveDown.Size = new System.Drawing.Size (31, 28);
 319                                 this.moveDown.TabIndex = 5;
 320                                 this.moveDown.Enabled = false;
 321                                 this.moveDown.Text = "Dn";
 322                                 this.moveDown.Click += new System.EventHandler (this.moveDown_Click);
 323                                 //
 324                                 // doAdd
 325                                 //
 326                                 this.doAdd.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
 327                                 this.doAdd.Location = new System.Drawing.Point (12, 346);
 328                                 this.doAdd.Size = new System.Drawing.Size (59, 25);
 329                                 this.doAdd.TabIndex = 1;
 330                                 this.doAdd.Text = "Add";
 331                                 this.doAdd.Click += new System.EventHandler (this.doAdd_Click);
 332                                 //
 333                                 // doRemove
 334                                 //
 335                                 this.doRemove.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
 336                                 this.doRemove.Location = new System.Drawing.Point (77, 346);
 337                                 this.doRemove.Size = new System.Drawing.Size (55, 25);
 338                                 this.doRemove.TabIndex = 2;
 339                                 this.doRemove.Text = "Remove";
 340                                 this.doRemove.Click += new System.EventHandler (this.doRemove_Click);
 341                                 //
 342                                 // doCancel
 343                                 //
 344                                 this.doCancel.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
 345                                 this.doCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel;
 346                                 this.doCancel.Location = new System.Drawing.Point (433, 345);
 347                                 this.doCancel.Size = new System.Drawing.Size (86, 26);
 348                                 this.doCancel.TabIndex = 8;
 349                                 this.doCancel.Text = "Cancel";
 350                                 this.doCancel.Click += new System.EventHandler (this.doCancel_Click);
 351                                 //
 352                                 // addType
 353                                 //
 354                                 this.addType.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
 355                                 this.addType.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
 356                                 this.addType.Location = new System.Drawing.Point (12, 319);
 357                                 this.addType.Size = new System.Drawing.Size (120, 21);
 358                                 this.addType.TabIndex = 3;
 359                                 //
 360                                 // DesignerForm
 361                                 //
 362                                 this.AcceptButton = this.doClose;
 363                                 this.CancelButton = this.doCancel;
 364                                 this.ClientSize = new System.Drawing.Size (531, 381);
 365                                 this.ControlBox = false;
 366                                 this.Controls.Add (this.addType);
 367                                 this.Controls.Add (this.doCancel);
 368                                 this.Controls.Add (this.doRemove);
 369                                 this.Controls.Add (this.doAdd);
 370                                 this.Controls.Add (this.moveDown);
 371                                 this.Controls.Add (this.moveUp);
 372                                 this.Controls.Add (this.doClose);
 373                                 this.Controls.Add (this.itemDisplay);
 374                                 this.Controls.Add (this.itemsList);
 375                                 this.Controls.Add (this.labelProperty);
 376                                 this.Controls.Add (this.labelMember);
 377                                 this.HelpButton = true;
 378                                 this.MaximizeBox = false;
 379                                 this.MinimizeBox = false;
 380                                 this.MinimumSize = new System.Drawing.Size (400, 300);
 381                                 this.ShowInTaskbar = false;
 382                                 this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
 383                                 this.ResumeLayout (false);
 384
 385                                 if (editor.CollectionType.IsGenericType)
 386                                         this.Text = editor.CollectionItemType.Name + " Collection Editor";
 387                                 else
 388                                         this.Text = editor.CollectionType.Name + " Collection Editor";
 389                                 foreach (Type type in editor.NewItemTypes)
 390                                         addType.Items.Add (type.Name);
 391                                 if (addType.Items.Count > 0)
 392                                         addType.SelectedIndex = 0;
 393                         }
 394
 395                         private void UpdateItems ()
 396                         {
 397                                 object[] items = editor.GetItems (EditValue);
 398                                 if (items != null) {
 399                                         itemsList.BeginUpdate ();
 400                                         itemsList.Items.Clear ();
 401                                         foreach (object o in items)
 402                                                 this.itemsList.Items.Add (new ObjectContainer (o, editor));
 403                                         if (itemsList.Items.Count > 0)
 404                                                 itemsList.SelectedIndex = 0;
 405                                         itemsList.EndUpdate ();
 406                                 }
 407                         }
 408
 409                         private void doClose_Click (object sender, EventArgs e)
 410                         {
 411                                 SetEditValue ();
 412                                 this.Close ();
 413                         }
 414
 415                         private void SetEditValue ()
 416                         {
 417                                 object[] items = new object[itemsList.Items.Count];
 418                                 for (int i = 0; i < itemsList.Items.Count; i++)
 419                                         items[i] = ((ObjectContainer)itemsList.Items[i]).Object;
 420                                 this.Items = items;
 421                         }
 422
 423                         private void doCancel_Click (object sender, EventArgs e)
 424                         {
 425                                 editor.CancelChanges ();
 426                                 this.Close ();
 427                         }
 428
 429                         private void itemsList_SelectedIndexChanged (object sender, EventArgs e)
 430                         {
 431                                 if (itemsList.SelectedIndex == -1) {
 432                                         itemDisplay.SelectedObject = null;
 433                                         return;
 434                                 }
 435
 436                                 if (itemsList.SelectedIndex <= 0 || itemsList.SelectedItems.Count > 1)
 437                                         moveUp.Enabled = false;
 438                                 else
 439                                         moveUp.Enabled = true;
 440                                 if (itemsList.SelectedIndex > itemsList.Items.Count - 2 || itemsList.SelectedItems.Count > 1)
 441                                         moveDown.Enabled = false;
 442                                 else
 443                                         moveDown.Enabled = true;
 444
 445                                 if (itemsList.SelectedItems.Count == 1)
 446                                 {
 447                                         ObjectContainer o = (ObjectContainer)itemsList.SelectedItem;
 448                                         if (Type.GetTypeCode (o.Object.GetType ()) != TypeCode.Object)
 449                                                 itemDisplay.SelectedObject = o;
 450                                         else
 451                                                 itemDisplay.SelectedObject = o.Object;
 452                                 }
 453                                 else
 454                                 {
 455                                         object[] items = new object[itemsList.SelectedItems.Count];
 456                                         for (int i = 0; i < itemsList.SelectedItems.Count; i++)
 457                                         {
 458                                                 ObjectContainer o = (ObjectContainer)itemsList.SelectedItem;
 459                                                 if (Type.GetTypeCode (o.Object.GetType ()) != TypeCode.Object)
 460                                                         items[i] = ((ObjectContainer)itemsList.SelectedItems[i]);
 461                                                 else
 462                                                         items[i] = ((ObjectContainer)itemsList.SelectedItems[i]).Object;
 463                                         }
 464                                         itemDisplay.SelectedObjects = items;
 465                                 }
 466                                 labelProperty.Text = ((ObjectContainer)itemsList.SelectedItem).Name + " properties:";
 467                         }
 468
 469                         private void itemDisplay_PropertyValueChanged (object sender, EventArgs e)
 470                         {
 471                                 int[] selected = new int[itemsList.SelectedItems.Count];
 472                                 for (int i = 0; i < itemsList.SelectedItems.Count; i++)
 473                                         selected[i] = itemsList.Items.IndexOf (itemsList.SelectedItems[i]);
 474
 475                                 // The list might be repopulated if a new instance of the collection edited
 476                                 // is created during the update. This happen for example for Arrays.
 477                                 SetEditValue ();
 478
 479                                 // Restore current selection in case the list gets repopulated.
 480                                 // Refresh the item after that to reflect possible value change.
 481                                 //
 482                                 itemsList.BeginUpdate ();
 483                                 itemsList.ClearSelected ();
 484                                 foreach (int index in selected) {
 485                                         itemsList.DoRefreshItem (index);
 486                                         itemsList.SetSelected (index, true);
 487                                 }
 488                                 itemsList.SelectedIndex = selected[0];
 489                                 itemsList.EndUpdate ();
 490                         }
 491
 492                         private void moveUp_Click (object sender, EventArgs e)
 493                         {
 494                                 if (itemsList.SelectedIndex <= 0)
 495                                         return;
 496
 497                                 object selected = itemsList.SelectedItem;
 498                                 int index = itemsList.SelectedIndex;
 499                                 itemsList.Items.RemoveAt (index);
 500                                 itemsList.Items.Insert (index - 1, selected);
 501                                 itemsList.SelectedIndex = index - 1;
 502                         }
 503
 504                         private void moveDown_Click (object sender, EventArgs e)
 505                         {
 506                                 if (itemsList.SelectedIndex > itemsList.Items.Count - 2)
 507                                         return;
 508
 509                                 object selected = itemsList.SelectedItem;
 510                                 int index = itemsList.SelectedIndex;
 511                                 itemsList.Items.RemoveAt (index);
 512                                 itemsList.Items.Insert (index + 1, selected);
 513                                 itemsList.SelectedIndex = index + 1;
 514                         }
 515
 516                         private void doAdd_Click (object sender, EventArgs e)
 517                         {
 518                                 object o;
 519                                 try {
 520                                         o = editor.CreateInstance (editor.NewItemTypes[addType.SelectedIndex]);
 521                                 } catch (Exception ex) {
 522                                         DisplayError (ex);
 523                                         return;
 524                                 }
 525                                 itemsList.Items.Add (new ObjectContainer (o, editor));
 526                                 itemsList.SelectedIndex = -1;
 527                                 itemsList.SelectedIndex = itemsList.Items.Count - 1;
 528                         }
 529
 530                         private void doRemove_Click (object sender, EventArgs e)
 531                         {
 532                                 if (itemsList.SelectedIndex != -1) {
 533                                         int[] selected = new int[itemsList.SelectedItems.Count];
 534                                         for (int i=0; i < itemsList.SelectedItems.Count; i++)
 535                                                 selected[i] = itemsList.Items.IndexOf (itemsList.SelectedItems[i]);
 536
 537                                         for (int i = selected.Length - 1; i >= 0; i--)
 538                                                 itemsList.Items.RemoveAt (selected[i]);
 539
 540                                         itemsList.SelectedIndex = Math.Min (selected[0], itemsList.Items.Count-1);
 541                                 }
 542                         }
 543
 544                         // OnEditValueChanged is called only if the  EditValue has changed,
 545                         // which is only in the case when a new instance of the collection is
 546                         // required, e.g for arrays.
 547                         //
 548                         protected override void OnEditValueChanged ()
 549                         {
 550                                 UpdateItems ();
 551                         }
 552                 }
 553
 554                 private Type type;
 555                 private Type collectionItemType;
 556                 private Type[] newItemTypes;
 557                 private ITypeDescriptorContext context;
 558                 private IServiceProvider provider;
 559                 private IWindowsFormsEditorService editorService;
 560
 561                 public CollectionEditor (Type type)
 562                 {
 563                         this.type = type;
 564                         this.collectionItemType = CreateCollectionItemType ();
 565                         this.newItemTypes = CreateNewItemTypes ();
 566                 }
 567
 568                 protected Type CollectionItemType
 569                 {
 570                         get { return collectionItemType; }
 571                 }
 572
 573                 protected Type CollectionType
 574                 {
 575                         get { return type; }
 576                 }
 577
 578                 protected ITypeDescriptorContext Context
 579                 {
 580                         get { return context; }
 581                 }
 582
 583                 protected virtual string HelpTopic
 584                 {
 585                         get { return "CollectionEditor"; }
 586                 }
 587
 588                 protected Type[] NewItemTypes
 589                 {
 590                         get { return newItemTypes; }
 591                 }
 592
 593                 protected virtual void CancelChanges ()
 594                 {
 595                 }
 596
 597                 protected virtual bool CanRemoveInstance (object value)
 598                 {
 599                         return true;
 600                 }
 601
 602                 protected virtual bool CanSelectMultipleInstances ()
 603                 {
 604                         return true;
 605                 }
 606
 607                 protected virtual CollectionEditor.CollectionForm CreateCollectionForm ()
 608                 {
 609                         return new ConcreteCollectionForm (this);
 610                 }
 611
 612                 protected virtual Type CreateCollectionItemType ()
 613                 {
 614                         PropertyInfo[] properties = type.GetProperties ();
 615                         foreach (PropertyInfo property in properties)
 616                                 if (property.Name == "Item")
 617                                         return property.PropertyType;
 618                         return typeof (object);
 619                 }
 620
 621                 protected virtual object CreateInstance (Type itemType)
 622                 {
 623                         object instance = null;
 624                         if (typeof (IComponent).IsAssignableFrom (itemType)) {
 625                                 IDesignerHost host = GetService (typeof (IDesignerHost)) as IDesignerHost;
 626                                 if (host != null)
 627                                         instance = host.CreateComponent (itemType);
 628                         }
 629
 630                         if (instance == null) {
 631                                 instance = TypeDescriptor.CreateInstance (provider, itemType, null, null);
 632                         }
 633                         return instance;
 634                 }
 635
 636                 protected virtual Type[] CreateNewItemTypes ()
 637                 {
 638                         return new Type[] { collectionItemType };
 639                 }
 640
 641                 protected virtual void DestroyInstance (object instance)
 642                 {
 643                         IComponent component = instance as IComponent;
 644                         if (component != null) {
 645                                 IDesignerHost host = GetService (typeof (IDesignerHost)) as IDesignerHost;
 646                                 if (host != null)
 647                                         host.DestroyComponent (component);
 648                         }
 649                 }
 650
 651                 public override object EditValue (ITypeDescriptorContext context, IServiceProvider provider, object value)
 652                 {
 653                         this.context = context;
 654                         this.provider = provider;
 655
 656                         if (context != null && provider != null)
 657                         {
 658                                 editorService = (IWindowsFormsEditorService)provider.GetService (typeof (IWindowsFormsEditorService));
 659                                 if (editorService != null)
 660                                 {
 661                                         CollectionForm editorForm = CreateCollectionForm ();
 662                                         editorForm.EditValue = value;
 663                                         editorForm.ShowEditorDialog (editorService);
 664                                         return editorForm.EditValue;
 665                                 }
 666                         }
 667                         return base.EditValue (context, provider, value);
 668                 }
 669
 670                 protected virtual string GetDisplayText (object value)
 671                 {
 672                         if (value == null)
 673                                 return string.Empty;
 674
 675                         PropertyInfo nameProperty = value.GetType ().GetProperty ("Name");
 676                         if (nameProperty != null)
 677                         {
 678                                 string data = (nameProperty.GetValue (value, null)) as string;
 679                                 if (data != null)
 680                                         if (data.Length != 0)
 681                                                 return data;
 682                         }
 683
 684                         if (Type.GetTypeCode (value.GetType ()) == TypeCode.Object)
 685                                 return value.GetType ().Name;
 686                         else
 687                                 return value.ToString ();
 688                 }
 689
 690                 public override UITypeEditorEditStyle GetEditStyle (ITypeDescriptorContext context)
 691                 {
 692                         return UITypeEditorEditStyle.Modal;
 693                 }
 694
 695                 protected virtual object[] GetItems (object editValue)
 696                 {
 697                         if (editValue == null)
 698                                 return new object[0];
 699                         ICollection collection = editValue as ICollection;
 700                         if (collection == null)
 701                                 return new object[0];
 702
 703                         object[] result = new object[collection.Count];
 704                         collection.CopyTo (result, 0);
 705                         return result;
 706                 }
 707
 708                 protected virtual IList GetObjectsFromInstance (object instance)
 709                 {
 710                         ArrayList list = new ArrayList ();
 711                         list.Add (instance);
 712                         return list;
 713                 }
 714
 715                 protected object GetService (Type serviceType)
 716                 {
 717                         return context.GetService (serviceType);
 718                 }
 719
 720                 protected virtual object SetItems (object editValue, object[] value)
 721                 {
 722                         IList list = (IList) editValue;
 723                         if (list == null)
 724                                 return null;
 725
 726                         list.Clear ();
 727                         foreach (object o in value)
 728                                 list.Add (o);
 729
 730                         return list;
 731                 }
 732
 733                 protected virtual void ShowHelp ()
 734                 {
 735                         //TODO: Fixme Add parent and URL
 736                         Help.ShowHelp (null, "", HelpTopic);
 737                 }
 738         }
 739 }