DialogPageContextComputer


1   /*******************************************************************************
2    * Copyright (c) 2000, 2006 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.ui.help;
12  
13  import java.util.ArrayList  ;
14  
15  import org.eclipse.core.runtime.Assert;
16  import org.eclipse.help.IContext;
17  import org.eclipse.jface.dialogs.IDialogPage;
18  import org.eclipse.swt.events.HelpEvent;
19  import org.eclipse.swt.widgets.Control;
20  
21  /**
22   * For determining the help context for controls in a dialog page.
23   * <p>
24   * This class may be instantiated; it is not intended to be subclassed.
25   * </p>
26   * @deprecated nested contexts are no longer supported by the help support system
27   */
28  public class DialogPageContextComputer implements IContextComputer {
29      private IDialogPage page;
30  
31      private ArrayList   contextList;
32  
33      private Object   context;
34  
35      /**
36       * Creates a new context computer for the given dialog page and help context.
37       *
38       * @param page the dialog page
39       * @param helpContext a single help context id (type <code>String</code>) or
40       *  help context object (type <code>IContext</code>)
41       */
42      public DialogPageContextComputer(IDialogPage page, Object   helpContext) {
43          Assert.isTrue(helpContext instanceof String  
44                  || helpContext instanceof IContext);
45          this.page = page;
46          context = helpContext;
47      }
48  
49      /**
50       * Add the contexts to the context list.
51       *
52       * @param object the contexts (<code>Object[]</code> or <code>IContextComputer</code>)
53       * @param event the help event 
54       */
55      private void addContexts(Object   object, HelpEvent event) {
56          Assert.isTrue(object instanceof Object  []
57                  || object instanceof IContextComputer
58                  || object instanceof String  );
59  
60          if (object instanceof String  ) {
61              contextList.add(object);
62              return;
63          }
64  
65          Object  [] contexts;
66          if (object instanceof IContextComputer) {
67              // get local contexts
68              contexts = ((IContextComputer) object).getLocalContexts(event);
69          } else {
70              contexts = (Object  []) object;
71          }
72  
73          // copy the contexts into our list  
74          for (int i = 0; i < contexts.length; i++) {
75              contextList.add(contexts[i]);
76          }
77      }
78  
79      /**
80       * Add the contexts for the given control to the context list.
81       *
82       * @param control the control from which to obtain the contexts
83       * @param event the help event 
84       */
85      private void addContextsForControl(Control control, HelpEvent event) {
86          // See if there is are help contexts on the control
87          Object   object = WorkbenchHelp.getHelp(control);
88  
89          if (object == null || object == this) {
90              // We need to check for this in order to avoid recursion
91              return;
92          }
93  
94          addContexts(object, event);
95      }
96  
97      /* (non-Javadoc)
98       * Method declared on IContextComputer.
99       */
100     public Object  [] computeContexts(HelpEvent event) {
101         contextList = new ArrayList  ();
102 
103         // Add the local context
104         contextList.add(context);
105 
106         // Add the contexts for the page
107         addContextsForControl(page.getControl(), event);
108 
109         // Add the contexts for the container shell 
110         addContextsForControl(page.getControl().getShell(), event);
111 
112         // Return the contexts
113         return contextList.toArray();
114     }
115 
116     /* (non-Javadoc)
117      * Method declared on IContextComputer.
118      */
119     public Object  [] getLocalContexts(HelpEvent event) {
120         return new Object  [] { context };
121     }
122 }
123
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags