sdk/samples/all in on code/Visual Studio 2010/CSBrowserHelperObject/HTMLDocumentEventHelper.cs

   1 /****************************** Module Header ******************************\
   2 * Module Name:  HTMLDocumentEventHelper.cs
   3 * Project:          CSBrowserHelperObject
   4 * Copyright (c) Microsoft Corporation.
   5 *
   6 * This ComVisible class HTMLDocumentEventHelper is used to set the event handler
   7 * of the HTMLDocument. The interface DispHTMLDocument defines many events like
   8 * oncontextmenu, onclick and so on, and these events could be set to an
   9 * HTMLEventHandler instance.
  10 *
  11 *
  12 * This source is subject to the Microsoft Public License.
  13 * See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  14 * All other rights reserved.
  15 *
  16 * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
  17 * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
  18 * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
  19 \***************************************************************************/
  20
  21 using System.Runtime.InteropServices;
  22 using mshtml;
  23
  24 namespace CSBrowserHelperObject
  25 {
  26     [ComVisible(true)]
  27     public class HTMLDocumentEventHelper
  28     {
  29         private HTMLDocument document;
  30
  31         public HTMLDocumentEventHelper(HTMLDocument document)
  32         {
  33             this.document = document;
  34         }
  35
  36         public event HtmlEvent oncontextmenu
  37         {
  38             add
  39             {
  40                 DispHTMLDocument dispDoc = this.document as DispHTMLDocument;
  41
  42                 object existingHandler = dispDoc.oncontextmenu;
  43                 HTMLEventHandler handler = existingHandler is HTMLEventHandler ?
  44                     existingHandler as HTMLEventHandler :
  45                     new HTMLEventHandler(this.document);
  46
  47                 // Set the handler to the oncontextmenu event.
  48                 dispDoc.oncontextmenu = handler;
  49
  50                 handler.eventHandler += value;
  51             }
  52             remove
  53             {
  54                 DispHTMLDocument dispDoc = this.document as DispHTMLDocument;
  55                 object existingHandler = dispDoc.oncontextmenu;
  56
  57                 HTMLEventHandler handler = existingHandler is HTMLEventHandler ?
  58                     existingHandler as HTMLEventHandler : null;
  59
  60                 if (handler != null)
  61                     handler.eventHandler -= value;
  62             }
  63         }
  64     }
  65
  66 }