BrowserManager


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.help.internal.browser;
12  
13  import java.util.ArrayList  ;
14  import java.util.Collection  ;
15  import java.util.Iterator  ;
16  
17  import org.eclipse.core.runtime.*;
18  import org.eclipse.help.browser.*;
19  import org.eclipse.help.internal.base.*;
20  import org.eclipse.osgi.service.environment.*;
21  import org.eclipse.osgi.util.NLS;
22  
23  /**
24   * Creates browser by delegating to appropriate browser adapter
25   */
26  public class BrowserManager {
27      public static final String   DEFAULT_BROWSER_ID_KEY = "default_browser"; //$NON-NLS-1$
28  
29      public static final String   BROWSER_ID_CUSTOM = HelpBasePlugin.PLUGIN_ID
30              + ".custombrowser"; //$NON-NLS-1$
31  
32      public static final String   BROWSER_ID_FIREFOX = HelpBasePlugin.PLUGIN_ID
33      + ".firefox"; //$NON-NLS-1$
34  
35      public static final String   BROWSER_ID_MOZILLA = HelpBasePlugin.PLUGIN_ID
36      + ".mozilla"; //$NON-NLS-1$
37  
38      public static final String   BROWSER_ID_NETSCAPE = HelpBasePlugin.PLUGIN_ID
39              + ".netscape"; //$NON-NLS-1$
40  
41      public static final String   BROWSER_ID_MAC_SYSTEM = HelpBasePlugin.PLUGIN_ID
42              + ".defaultBrowserMacOSX"; //$NON-NLS-1$
43  
44      public static final String   BROWSER_ID_EMBEDDED = "org.eclipse.help.ui.embeddedbrowser"; //$NON-NLS-1$
45  
46      public static final String   BROWSER_ID_SYSTEM = "org.eclipse.help.ui.systembrowser"; //$NON-NLS-1$
47  
48      private static BrowserManager instance;
49  
50      private boolean initialized = false;
51  
52      private BrowserDescriptor currentBrowserDesc;
53  
54      private BrowserDescriptor defaultBrowserDesc;
55  
56      private BrowserDescriptor[] browsersDescriptors;
57  
58      private BrowserDescriptor internalBrowserDesc;
59  
60      private Collection   browsers = new ArrayList  ();
61  
62      private boolean alwaysUseExternal = false;
63  
64      /**
65       * Private Constructor
66       */
67      private BrowserManager() {
68      }
69  
70      /**
71       * Initialize
72       */
73      private void init() {
74          initialized = true;
75          // Find all available browsers
76          browsersDescriptors = createBrowserDescriptors();
77          // 1. set default browser from preferences
78          String   defBrowserID = HelpBasePlugin.getDefault()
79                  .getPluginPreferences()
80                  .getDefaultString(DEFAULT_BROWSER_ID_KEY);
81          if (defBrowserID != null && (!"".equals(defBrowserID))) { //$NON-NLS-1$
82              setDefaultBrowserID(defBrowserID);
83          }
84          // 2. set default browser to embedded
85          //      if (defaultBrowserDesc == null) {
86          //          setDefaultBrowserID(BROWSER_ID_EMBEDDED);
87          //      }
88          // 3. set default browser to help implementation of system specific
89          // browser
90          String   os = Platform.getOS();
91          if (defaultBrowserDesc == null) {
92              if (Constants.WS_WIN32.equalsIgnoreCase(os)) {
93                  setDefaultBrowserID(BROWSER_ID_SYSTEM);
94              } else if (Constants.OS_AIX.equalsIgnoreCase(os)
95                      || (Constants.OS_HPUX.equalsIgnoreCase(os))
96                      || (Constants.OS_LINUX.equalsIgnoreCase(os))
97                      || (Constants.OS_SOLARIS.equalsIgnoreCase(os))) {
98                  setDefaultBrowserID(BROWSER_ID_MOZILLA);
99                  if (defaultBrowserDesc == null) {
100                     setDefaultBrowserID(BROWSER_ID_FIREFOX);
101                 }
102                 if (defaultBrowserDesc == null) {
103                     setDefaultBrowserID(BROWSER_ID_NETSCAPE);
104                 }
105             } else if (Constants.OS_MACOSX.equalsIgnoreCase(os)) {
106                 setDefaultBrowserID(BROWSER_ID_MAC_SYSTEM);
107             }
108         }
109         // 4. set browser to one of externally contributed
110         if (defaultBrowserDesc == null) {
111             for (int i = 0; i < browsersDescriptors.length; i++) {
112                 if (BROWSER_ID_CUSTOM.equals(browsersDescriptors[i].getID())) {
113                     defaultBrowserDesc = browsersDescriptors[i];
114                 }
115             }
116         }
117         // 5. let user specify program
118         if (defaultBrowserDesc == null) {
119             setDefaultBrowserID(BROWSER_ID_CUSTOM);
120         }
121         // 6. use null browser
122         if (defaultBrowserDesc == null) {
123             // If no browsers at all, use the Null Browser Adapter
124             defaultBrowserDesc = new BrowserDescriptor("", "Null Browser", //$NON-NLS-1$ //$NON-NLS-2$
125                     new IBrowserFactory() {
126                         public boolean isAvailable() {
127                             return true;
128                         }
129 
130                         public IBrowser createBrowser() {
131                             return new IBrowser() {
132                                 public void close() {
133                                 }
134 
135                                 public void displayURL(String   url) {
136                                     HelpBasePlugin
137                                             .logError(
138                                                     "There is no browser adapter configured to display " //$NON-NLS-1$
139                                                             + url
140                                                             + ".  Ensure that you have a required browser and adapter installed, and that the browser program is available on the system path.", //$NON-NLS-1$
141                                                     null);
142                                     String   msg = NLS.bind(HelpBaseResources.no_browsers, url);
143                                     BaseHelpSystem.getDefaultErrorUtil()
144                                             .displayError(msg);
145                                 }
146 
147                                 public boolean isCloseSupported() {
148                                     return false;
149                                 }
150 
151                                 public boolean isSetLocationSupported() {
152                                     return false;
153                                 }
154 
155                                 public boolean isSetSizeSupported() {
156                                     return false;
157                                 }
158 
159                                 public void setLocation(int width, int height) {
160                                 }
161 
162                                 public void setSize(int x, int y) {
163                                 }
164                             };
165                         }
166                     });
167         }
168         // initialize current browser
169         String   curBrowserID = HelpBasePlugin.getDefault()
170                 .getPluginPreferences().getString(DEFAULT_BROWSER_ID_KEY);
171         if (curBrowserID != null && (!"".equals(curBrowserID))) { //$NON-NLS-1$
172             setCurrentBrowserID(curBrowserID);
173             // may fail if such browser does not exist
174         }
175         if (currentBrowserDesc == null) {
176             setCurrentBrowserID(getDefaultBrowserID());
177         }
178         setAlwaysUseExternal(HelpBasePlugin.getDefault().getPluginPreferences()
179                 .getBoolean(IHelpBaseConstants.P_KEY_ALWAYS_EXTERNAL_BROWSER));
180     }
181 
182     /**
183      * Obtains singleton instance.
184      */
185     public static BrowserManager getInstance() {
186         if (instance == null)
187             instance = new BrowserManager();
188         return instance;
189     }
190 
191     /**
192      * Creates all adapters, and returns available ones.
193      */
194     private BrowserDescriptor[] createBrowserDescriptors() {
195         if (this.browsersDescriptors != null)
196             return this.browsersDescriptors;
197         Collection   bDescriptors = new ArrayList  ();
198         IConfigurationElement configElements[] = Platform
199                 .getExtensionRegistry().getConfigurationElementsFor(
200                         HelpBasePlugin.PLUGIN_ID, "browser"); //$NON-NLS-1$
201         for (int i = 0; i < configElements.length; i++) {
202             if (!configElements[i].getName().equals("browser")) //$NON-NLS-1$
203                 continue;
204             String   id = configElements[i].getAttribute("id"); //$NON-NLS-1$
205             if (id == null)
206                 continue;
207             String   label = configElements[i].getAttribute("name"); //$NON-NLS-1$
208             if (label == null)
209                 continue;
210             try {
211                 Object   adapter = configElements[i]
212                         .createExecutableExtension("factoryclass"); //$NON-NLS-1$
213                 if (!(adapter instanceof IBrowserFactory))
214                     continue;
215                 if (((IBrowserFactory) adapter).isAvailable()) {
216                     BrowserDescriptor descriptor = new BrowserDescriptor(id,
217                             label, (IBrowserFactory) adapter);
218                     if (descriptor.isExternal()) {
219                         bDescriptors.add(descriptor);
220                     } else {
221                         internalBrowserDesc = descriptor;
222                     }
223                 }
224             } catch (CoreException ce) {
225             }
226         }
227         this.browsersDescriptors = (BrowserDescriptor[]) bDescriptors
228                 .toArray(new BrowserDescriptor[bDescriptors.size()]);
229         return this.browsersDescriptors;
230     }
231 
232     /**
233      * Obtains browsers descriptors.
234      */
235     public BrowserDescriptor[] getBrowserDescriptors() {
236         if (!initialized) {
237             init();
238         }
239         return this.browsersDescriptors;
240     }
241 
242     /**
243      * Gets the currentBrowserID.
244      * 
245      * @return Returns a String or null if not set
246      */
247     public String   getCurrentBrowserID() {
248         if (!initialized) {
249             init();
250         }
251         if (currentBrowserDesc == null)
252             return null;
253         return currentBrowserDesc.getID();
254     }
255 
256     /**
257      * Gets the currentBrowserID.
258      * 
259      * @return Returns a String or null if not set
260      */
261     public String   getCurrentInternalBrowserID() {
262         if (!initialized) {
263             init();
264         }
265         if (isEmbeddedBrowserPresent() && !alwaysUseExternal) {
266             return internalBrowserDesc.getID();
267         }
268         return getCurrentBrowserID();
269     }
270 
271     /**
272      * Gets the currentBrowserID.
273      * 
274      * @return Returns a String or null if not set
275      */
276     public String   getDefaultBrowserID() {
277         if (!initialized) {
278             init();
279         }
280         if (defaultBrowserDesc == null)
281             return null;
282         return defaultBrowserDesc.getID();
283     }
284 
285     /**
286      * Sets the currentBrowserID. If browser of given ID does not exists, the
287      * method does nothing
288      * 
289      * @param currentAdapterID
290      *            The ID of the adapter to to set as current
291      */
292     public void setCurrentBrowserID(String   currentAdapterID) {
293         if (!initialized) {
294             init();
295         }
296         for (int i = 0; i < browsersDescriptors.length; i++) {
297             if (browsersDescriptors[i].getID().equals(currentAdapterID)) {
298                 currentBrowserDesc = browsersDescriptors[i];
299                 return;
300             }
301         }
302     }
303 
304     /**
305      * Sets the defaultBrowserID. If browser of given ID does not exists, the
306      * method does nothing
307      * 
308      * @param defaultAdapterID
309      *            The ID of the adapter to to set as default
310      */
311     private void setDefaultBrowserID(String   defaultAdapterID) {
312         if (!initialized) {
313             init();
314         }
315         for (int i = 0; i < browsersDescriptors.length; i++) {
316             if (browsersDescriptors[i].getID().equals(defaultAdapterID)) {
317                 defaultBrowserDesc = browsersDescriptors[i];
318                 return;
319             }
320         }
321     }
322 
323     /**
324      * Creates web browser If preferences specify to always use external, the
325      * parameter will not be honored
326      */
327     public IBrowser createBrowser(boolean external) {
328         if (!initialized) {
329             init();
330         }
331         //external = external || alwaysUseExternal;
332         //return createBrowserAdapter(forceExternal);
333         if (external) {
334             return new CurrentBrowser(createBrowserAdapter(true),
335                     getCurrentBrowserID(), true);
336         }
337         return new CurrentBrowser(createBrowserAdapter(alwaysUseExternal),
338                 getCurrentInternalBrowserID(), false);
339     }
340 
341     /**
342      * Creates web browser
343      */
344     public IBrowser createBrowser() {
345         return createBrowser(true);
346     }
347 
348     /**
349      * Creates web browser for external == false, if no internal browsers are
350      * present it will create external one
351      */
352     private IBrowser createBrowserAdapter(boolean external) {
353         if (!initialized) {
354             init();
355         }
356         IBrowser browser = null;
357         if (!external && isEmbeddedBrowserPresent()) {
358             browser = internalBrowserDesc.getFactory().createBrowser();
359         } else {
360             browser = currentBrowserDesc.getFactory().createBrowser();
361         }
362         browsers.add(browser);
363         return browser;
364     }
365 
366     /**
367      * Closes all browsers created
368      */
369     public void closeAll() {
370         if (!initialized) {
371             // nothing to do, do not initialize
372             return;
373         }
374         for (Iterator   it = browsers.iterator(); it.hasNext();) {
375             IBrowser browser = (IBrowser) it.next();
376             browser.close();
377         }
378     }
379 
380     public boolean isEmbeddedBrowserPresent() {
381         if (!initialized) {
382             init();
383         }
384         return internalBrowserDesc != null;
385     }
386 
387     public void setAlwaysUseExternal(boolean alwaysExternal) {
388         if (!initialized) {
389             init();
390         }
391         alwaysUseExternal = alwaysExternal || !isEmbeddedBrowserPresent();
392     }
393 
394     public boolean isAlwaysUseExternal() {
395         if (!isEmbeddedBrowserPresent()) {
396             return true;
397         }
398         return alwaysUseExternal;
399     }
400 }
401
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