HelpDisplay


1   /*******************************************************************************
2    * Copyright (c) 2000, 2007 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.help.internal.base;
12  
13  import java.io.UnsupportedEncodingException  ;
14  import java.net.URLEncoder  ;
15  
16  import org.eclipse.core.runtime.Platform;
17  import org.eclipse.help.IContext;
18  import org.eclipse.help.IHelpResource;
19  import org.eclipse.help.IToc;
20  import org.eclipse.help.internal.HelpPlugin;
21  import org.eclipse.help.internal.context.Context;
22  import org.eclipse.help.internal.server.WebappManager;
23  import org.eclipse.osgi.util.NLS;
24  
25  /**
26   * This class provides methods to display help. It is independent of platform
27   * UI.
28   */
29  public class HelpDisplay {
30  
31      /**
32       * Constructor.
33       */
34      public HelpDisplay() {
35          super();
36      }
37  
38      /**
39       * Displays help.
40       */
41      public void displayHelp(boolean forceExternal) {
42          displayHelpURL(null, forceExternal);
43      }
44  
45      /**
46       * Displays a help resource specified as a url.
47       * <ul>
48       * <li>a URL in a format that can be returned by
49       * {@link  org.eclipse.help.IHelpResource#getHref() IHelpResource.getHref()}
50       * <li>a URL query in the format format
51       * <em>key=value&amp;key=value ...</em> The valid keys are: "tab", "toc",
52       * "topic", "contextId". For example,
53       * <em>toc="/myplugin/mytoc.xml"&amp;topic="/myplugin/references/myclass.html"</em>
54       * is valid.
55       * </ul>
56       */
57      public void displayHelpResource(String   href, boolean forceExternal) {
58          // check if this is a toc
59          IToc toc = HelpPlugin.getTocManager().getToc(href, Platform.getNL());
60          if (toc != null)
61              try {
62                  displayHelpURL(
63                          "toc=" + URLEncoder.encode(toc.getHref(), "UTF-8"), forceExternal); //$NON-NLS-1$ //$NON-NLS-2$
64              } catch (UnsupportedEncodingException   uee) {
65              }
66          else if (href != null && (href.startsWith("tab=") //$NON-NLS-1$
67                  || href.startsWith("toc=") //$NON-NLS-1$
68                  || href.startsWith("topic=") //$NON-NLS-1$
69          || href.startsWith("contextId="))) { //$NON-NLS-1$ // assume it is a query string
70              displayHelpURL(href, forceExternal);
71          } else { // assume this is a topic
72              if (getNoframesURL(href) == null) {
73                  try {
74                      displayHelpURL(
75                              "topic=" + URLEncoder.encode(href, "UTF-8"), forceExternal); //$NON-NLS-1$ //$NON-NLS-2$
76                  } catch (UnsupportedEncodingException   uee) {
77                  }
78              } else if (href.startsWith("jar:") || href.startsWith("platform:")) { //$NON-NLS-1$ //$NON-NLS-2$
79                  // topic from a jar/workspace to display without frames
80                  displayHelpURL(
81                          getBaseURL() + "nftopic/" + getNoframesURL(href), true); //$NON-NLS-1$
82              } else {
83                  displayHelpURL(getNoframesURL(href), true);
84              }
85          }
86      }
87  
88      /**
89       * Display help for the a given topic and related topics.
90       * 
91       * @param context
92       *            context for which related topics will be displayed
93       * @param topic
94       *            related topic to be selected
95       */
96      public void displayHelp(IContext context, IHelpResource topic,
97              boolean forceExternal) {
98          if (context == null || topic == null || topic.getHref() == null)
99              return;
100         String   topicURL = getTopicURL(topic.getHref());
101         if (getNoframesURL(topicURL) == null) {
102             try {
103                 String   url = "tab=links" //$NON-NLS-1$
104                         + "&contextId=" //$NON-NLS-1$
105                         + URLEncoder.encode(getContextID(context), "UTF-8") //$NON-NLS-1$
106                         + "&topic=" //$NON-NLS-1$
107                         + URLEncoder.encode(topicURL, "UTF-8"); //$NON-NLS-1$
108                 displayHelpURL(url, forceExternal);
109             } catch (UnsupportedEncodingException   uee) {
110             }
111 
112         } else if (topicURL.startsWith("jar:file:")) { //$NON-NLS-1$
113             // topic from a jar to display without frames
114             displayHelpURL(
115                     getBaseURL() + "nftopic/" + getNoframesURL(topicURL), true); //$NON-NLS-1$
116         } else {
117             displayHelpURL(getNoframesURL(topicURL), true);
118         }
119     }
120 
121     /**
122      * Display help to search view for given query and selected topic.
123      * 
124      * @param searchQuery
125      *            search query in URL format key=value&key=value
126      * @param topic
127      *            selected from the search results
128      */
129     public void displaySearch(String   searchQuery, String   topic,
130             boolean forceExternal) {
131         if (searchQuery == null || topic == null)
132             return;
133         if (getNoframesURL(topic) == null) {
134             try {
135                 String   url = "tab=search&" //$NON-NLS-1$
136                         + searchQuery + "&topic=" //$NON-NLS-1$
137                         + URLEncoder.encode(getTopicURL(topic), "UTF-8"); //$NON-NLS-1$
138                 displayHelpURL(url, forceExternal);
139             } catch (UnsupportedEncodingException   uee) {
140             }
141 
142         } else {
143             displayHelpURL(getNoframesURL(topic), true);
144         }
145     }
146 
147     /**
148      * Displays the specified url. The url can contain query parameters to
149      * identify how help displays the document
150      */
151     private void displayHelpURL(String   helpURL, boolean forceExternal) {
152         if (!BaseHelpSystem.ensureWebappRunning()) {
153             return;
154         }
155         if (BaseHelpSystem.getMode() == BaseHelpSystem.MODE_STANDALONE) {
156             // wait for Display to be created
157             DisplayUtils.waitForDisplay();
158         }
159 
160         try {
161             /*
162             if (helpURL == null || helpURL.length() == 0) {
163                 BaseHelpSystem.getHelpBrowser(forceExternal).displayURL(
164                         getFramesetURL());
165             } else if (helpURL.startsWith("tab=") //$NON-NLS-1$
166                     || helpURL.startsWith("toc=") //$NON-NLS-1$
167                     || helpURL.startsWith("topic=") //$NON-NLS-1$
168                     || helpURL.startsWith("contextId=")) { //$NON-NLS-1$
169                 BaseHelpSystem.getHelpBrowser(forceExternal).displayURL(
170                         getFramesetURL() + "?" + helpURL); //$NON-NLS-1$
171             } else {
172                 BaseHelpSystem.getHelpBrowser(forceExternal)
173                         .displayURL(helpURL);
174             }
175             */
176             if (helpURL == null || helpURL.length() == 0) {
177                 helpURL = getFramesetURL();
178             } else if (helpURL.startsWith("tab=") //$NON-NLS-1$
179                     || helpURL.startsWith("toc=") //$NON-NLS-1$
180                     || helpURL.startsWith("topic=") //$NON-NLS-1$
181                     || helpURL.startsWith("contextId=")) { //$NON-NLS-1$
182                 helpURL = getFramesetURL() + "?" + helpURL; //$NON-NLS-1$
183             }
184             BaseHelpSystem.getHelpBrowser(forceExternal)
185                         .displayURL(helpURL);
186         } catch (Exception   e) {
187             HelpBasePlugin
188                     .logError(
189                             "An exception occurred while launching help.  Check the log at " + Platform.getLogFileLocation().toOSString(), e); //$NON-NLS-1$
190             BaseHelpSystem.getDefaultErrorUtil()
191                     .displayError(
192                             NLS.bind(HelpBaseResources.HelpDisplay_exceptionMessage, Platform.getLogFileLocation().toOSString()));
193         }
194     }
195 
196     private String   getContextID(IContext context) {
197         if (context instanceof Context) {
198             return ((Context)context).getId();
199         }
200         return HelpPlugin.getContextManager().addContext(context);
201     }
202 
203     private String   getBaseURL() {
204         return "http://" //$NON-NLS-1$
205                 + WebappManager.getHost() + ":" //$NON-NLS-1$
206                 + WebappManager.getPort() + "/help/"; //$NON-NLS-1$
207     }
208 
209     private String   getFramesetURL() {
210         return getBaseURL() + "index.jsp"; //$NON-NLS-1$
211     }
212 
213     private String   getTopicURL(String   topic) {
214         if (topic == null)
215             return null;
216         if (topic.startsWith("../")) //$NON-NLS-1$
217             topic = topic.substring(2);
218         /*
219          * if (topic.startsWith("/")) { String base = "http://" +
220          * AppServer.getHost() + ":" + AppServer.getPort(); base +=
221          * "/help/content/help:"; topic = base + topic; }
222          */
223         return topic;
224     }
225 
226     /**
227      * If href contains URL parameter noframes=true return href with that
228      * paramter removed, otherwise returns null
229      * 
230      * @param href
231      * @return String or null
232      */
233     private String   getNoframesURL(String   href) {
234         if (href == null) {
235             return null;
236         }
237         int ix = href.indexOf("?noframes=true&"); //$NON-NLS-1$
238         if (ix >= 0) {
239             //remove noframes=true&
240             return href.substring(0, ix + 1)
241                     + href.substring(ix + "?noframes=true&".length()); //$NON-NLS-1$
242 
243         }
244         ix = href.indexOf("noframes=true"); //$NON-NLS-1$
245         if (ix > 0) {
246             //remove &noframes=true
247             return href.substring(0, ix - 1)
248                     + href.substring(ix + "noframes=true".length()); //$NON-NLS-1$
249         }
250         // can be displayed in frames
251         return null;
252     }
253 
254 }
255
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