developer/VSSDK/VisualStudioIntegration/Common/Source/CSharp/Shell/SelectionContainer.cs

   1
   2 namespace Microsoft.VisualStudio.Shell
   3 {
   4     using System;
   5     using System.Collections;
   6     using System.Runtime.InteropServices;
   7     using ISelectionContainer = Microsoft.VisualStudio.Shell.Interop.ISelectionContainer;
   8
   9     /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer"]/*' />
  10     /// <devdoc>
  11     /// This class implements the ISelectionContainer interface. It can be used to show
  12     /// informations on the property window.
  13     /// </devdoc>
  14     [CLSCompliant(false)]
  15     public class SelectionContainer :
  16         ISelectionContainer
  17     {
  18         private ICollection     _selectableObjects;
  19         private ICollection     _selectedObjects;
  20         private readonly bool   _selectableReadOnly;
  21         private readonly bool   _selectedReadOnly;
  22
  23         private static ICollection _emptyCollection = new Object[0];
  24
  25         // Constants for selection container flags.
  26         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.ALL"]/*' />
  27         public const uint ALL = 0x1;
  28         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SELECTED"]/*' />
  29         public const uint SELECTED = 0x2;
  30
  31         private const int SELOBJ_ACTIVATE_WINDOW = 0x1;
  32
  33
  34         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SelectionContainer"]/*' />
  35         /// <devdoc>
  36         /// Creates a container with empty collections of selected and selectable objects.
  37         /// </devdoc>
  38         public SelectionContainer()
  39         {
  40             _selectableObjects = _emptyCollection;
  41             _selectedObjects = _emptyCollection;
  42         }
  43
  44         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SelectionContainer1"]/*' />
  45         /// <devdoc>
  46         /// Creates a selection container with empty collections of selected and selectable objects.
  47         /// </devdoc>
  48         /// <param name="selectableReadOnly">Specifies if the collection of the selectable objects is read only.</param>
  49         /// <param name="selectedReadOnly">Specifies if the selection is read only.</param>
  50         public SelectionContainer(bool selectableReadOnly, bool selectedReadOnly) : this()
  51         {
  52             _selectableReadOnly = selectableReadOnly;
  53             _selectedReadOnly = selectedReadOnly;
  54         }
  55
  56         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SelectableObjects"]/*' />
  57         /// <devdoc>
  58         /// Get or set the collection of the selectable objects
  59         /// </devdoc>
  60         public ICollection SelectableObjects
  61         {
  62             get
  63             {
  64                 return _selectableObjects;
  65             }
  66             set
  67             {
  68                 if (value == null)
  69                 {
  70                     value = _emptyCollection;
  71                 }
  72                 _selectableObjects = value;
  73             }
  74         }
  75
  76         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SelectedObjects"]/*' />
  77         /// <devdoc>
  78         /// Get or set the collection of the selected objects.
  79         /// </devdoc>
  80         public ICollection SelectedObjects
  81         {
  82             get
  83             {
  84                 return _selectedObjects;
  85             }
  86             set
  87             {
  88                 if (value == null)
  89                 {
  90                     value = _emptyCollection;
  91                 }
  92                 _selectedObjects = value;
  93             }
  94         }
  95
  96         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.SelectedObjectsChanged"]/*' />
  97         /// <devdoc>
  98         /// This event is fired when the selection changes.
  99         /// </devdoc>
 100         public event EventHandler SelectedObjectsChanged;
 101
 102         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.ActivateObjects"]/*' />
 103         /// <devdoc>
 104         /// Activates the selected objects. Its default implementation is empty.
 105         /// </devdoc>
 106         protected virtual void ActivateObjects()
 107         {
 108             // This default implementation of this function is empty.
 109         }
 110
 111         // Helper function to change the selected objects
 112         private void ChangeSelection(object[] prgUnkObjects, int dwFlags)
 113         {
 114             // Check if it is possible to change the selection.
 115             if (_selectedReadOnly) throw new InvalidOperationException();
 116             // Store the array of selected object in the internal array
 117             SelectedObjects = prgUnkObjects;
 118             // Raise the "Selected objects changed" event.
 119             if (SelectedObjectsChanged != null) SelectedObjectsChanged(this, EventArgs.Empty);
 120             // Check if the objects need to be activated
 121             if ( (dwFlags & SELOBJ_ACTIVATE_WINDOW) != 0 )
 122             {
 123                 ActivateObjects();
 124             }
 125         }
 126
 127
 128
 129 #region ISelectionContainer Members
 130
 131         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.ISelectionContainer.CountObjects"]/*' />
 132         /// <internalonly/>
 133         int ISelectionContainer.CountObjects(uint dwFlags, out uint pc)
 134         {
 135             switch (dwFlags)
 136             {
 137                 case ALL:
 138                     pc = (uint)SelectableObjects.Count;
 139                     break;
 140
 141                 case SELECTED:
 142                     pc = (uint)SelectedObjects.Count;
 143                     break;
 144
 145                 default:
 146                     throw new ArgumentException(SR.GetString(SR.General_UnsupportedValue, dwFlags), "dwFlags");
 147             }
 148             return NativeMethods.S_OK;
 149         }
 150
 151         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.ISelectionContainer.GetObjects"]/*' />
 152         /// <internalonly/>
 153         int ISelectionContainer.GetObjects(uint dwFlags, uint cObjects, object[] apUnkObjects)
 154         {
 155             ICollection objects = null;
 156
 157             switch (dwFlags)
 158             {
 159                 case ALL:
 160                     objects = SelectableObjects;
 161                     break;
 162
 163                 case SELECTED:
 164                     objects = SelectedObjects;
 165                     break;
 166
 167                 default:
 168                     throw new ArgumentException(SR.GetString(SR.General_UnsupportedValue, dwFlags), "dwFlags");
 169             }
 170
 171             int idx = 0;
 172             foreach (object obj in objects)
 173             {
 174                 if (idx >= cObjects || idx >= apUnkObjects.Length)
 175                 {
 176                     break;
 177                 }
 178                 apUnkObjects[idx++] = obj;
 179             }
 180             return NativeMethods.S_OK;
 181         }
 182
 183         /// <include file='doc\SelectionContainer.uex' path='docs/doc[@for="SelectionContainer.ISelectionContainer.SelectObjects"]/*' />
 184         /// <internalonly/>
 185         int ISelectionContainer.SelectObjects(uint cSelect, object[] apUnkSelect, uint dwFlags)
 186         {
 187             ChangeSelection(apUnkSelect, (int)dwFlags);
 188             return NativeMethods.S_OK;
 189         }
 190
 191 #endregion
 192     }
 193 }