summaryrefslogtreecommitdiffstats
path: root/application/basilisk/components/preferences/in-content/main.js
blob: bac771bece97d7d8c093f3557001d9b9d1805134 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

Components.utils.import("resource://gre/modules/Downloads.jsm");
Components.utils.import("resource://gre/modules/FileUtils.jsm");
Components.utils.import("resource://gre/modules/Task.jsm");
Components.utils.import("resource:///modules/ShellService.jsm");
Components.utils.import("resource:///modules/TransientPrefs.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "OS",
                                  "resource://gre/modules/osfile.jsm");

var gMainPane = {
  /**
   * Initialization of this.
   */
  init: function ()
  {
    function setEventListener(aId, aEventType, aCallback)
    {
      document.getElementById(aId)
              .addEventListener(aEventType, aCallback.bind(gMainPane));
    }

    if (AppConstants.HAVE_SHELL_SERVICE) {
      this.updateSetDefaultBrowser();
      if (AppConstants.platform == "win") {
        // In Windows 8 we launch the control panel since it's the only
        // way to get all file type association prefs. So we don't know
        // when the user will select the default.  We refresh here periodically
        // in case the default changes. On other Windows OS's defaults can also
        // be set while the prefs are open.
        window.setInterval(this.updateSetDefaultBrowser.bind(this), 1000);
      }
    }

    // set up the "use current page" label-changing listener
    this._updateUseCurrentButton();
    window.addEventListener("focus", this._updateUseCurrentButton.bind(this), false);

    this.updateBrowserStartupLastSession();

    if (AppConstants.platform == "win") {
      // Functionality for "Show tabs in taskbar" on Windows 7 and up.
      try {
        let sysInfo = Cc["@mozilla.org/system-info;1"].
                      getService(Ci.nsIPropertyBag2);
        let ver = parseFloat(sysInfo.getProperty("version"));
        let showTabsInTaskbar = document.getElementById("showTabsInTaskbar");
        showTabsInTaskbar.hidden = ver < 6.1;
      } catch (ex) {}
    }

    // The "closing multiple tabs" and "opening multiple tabs might slow down
    // &brandShortName;" warnings provide options for not showing these
    // warnings again. When the user disabled them, we provide checkboxes to
    // re-enable the warnings.
    if (!TransientPrefs.prefShouldBeVisible("browser.tabs.warnOnClose"))
      document.getElementById("warnCloseMultiple").hidden = true;
    if (!TransientPrefs.prefShouldBeVisible("browser.tabs.warnOnOpen"))
      document.getElementById("warnOpenMany").hidden = true;

    setEventListener("browser.privatebrowsing.autostart", "change",
                     gMainPane.updateBrowserStartupLastSession);
    setEventListener("browser.download.dir", "change",
                     gMainPane.displayDownloadDirPref);
    if (AppConstants.HAVE_SHELL_SERVICE) {
      setEventListener("setDefaultButton", "command",
                       gMainPane.setDefaultBrowser);
    }
    setEventListener("useCurrent", "command",
                     gMainPane.setHomePageToCurrent);
    setEventListener("useBookmark", "command",
                     gMainPane.setHomePageToBookmark);
    setEventListener("restoreDefaultHomePage", "command",
                     gMainPane.restoreDefaultHomePage);
    setEventListener("chooseFolder", "command",
                     gMainPane.chooseFolder);

    if (AppConstants.MOZ_DEV_EDITION) {
      let uAppData = OS.Constants.Path.userApplicationDataDir;
      let ignoreSeparateProfile = OS.Path.join(uAppData, "ignore-dev-edition-profile");

      setEventListener("separateProfileMode", "command", gMainPane.separateProfileModeChange);
      let separateProfileModeCheckbox = document.getElementById("separateProfileMode");
      setEventListener("getStarted", "click", gMainPane.onGetStarted);

      OS.File.stat(ignoreSeparateProfile).then(() => separateProfileModeCheckbox.checked = false,
                                               () => separateProfileModeCheckbox.checked = true);
    }

    // Notify observers that the UI is now ready
    Components.classes["@mozilla.org/observer-service;1"]
              .getService(Components.interfaces.nsIObserverService)
              .notifyObservers(window, "main-pane-loaded", null);
  },

  enableE10SChange: function ()
  {
    // **STUB**
  },

  separateProfileModeChange: function ()
  {
    if (AppConstants.MOZ_DEV_EDITION) {
      function quitApp() {
        Services.startup.quit(Ci.nsIAppStartup.eAttemptQuit |  Ci.nsIAppStartup.eRestartNotSameProfile);
      }
      function revertCheckbox(error) {
        separateProfileModeCheckbox.checked = !separateProfileModeCheckbox.checked;
        if (error) {
          Cu.reportError("Failed to toggle separate profile mode: " + error);
        }
      }
      function createOrRemoveSpecialDevEditionFile(onSuccess) {
        let uAppData = OS.Constants.Path.userApplicationDataDir;
        let ignoreSeparateProfile = OS.Path.join(uAppData, "ignore-dev-edition-profile");

        if (separateProfileModeCheckbox.checked) {
          OS.File.remove(ignoreSeparateProfile).then(onSuccess, revertCheckbox);
        } else {
          OS.File.writeAtomic(ignoreSeparateProfile, new Uint8Array()).then(onSuccess, revertCheckbox);
        }
      }

      let separateProfileModeCheckbox = document.getElementById("separateProfileMode");
      let button_index = confirmRestartPrompt(separateProfileModeCheckbox.checked,
                                              0, false, true);
      switch (button_index) {
        case CONFIRM_RESTART_PROMPT_CANCEL:
          revertCheckbox();
          return;
        case CONFIRM_RESTART_PROMPT_RESTART_NOW:
          const Cc = Components.classes, Ci = Components.interfaces;
          let cancelQuit = Cc["@mozilla.org/supports-PRBool;1"]
                             .createInstance(Ci.nsISupportsPRBool);
          Services.obs.notifyObservers(cancelQuit, "quit-application-requested",
                                        "restart");
          if (!cancelQuit.data) {
            createOrRemoveSpecialDevEditionFile(quitApp);
            return;
          }

          // Revert the checkbox in case we didn't quit
          revertCheckbox();
          return;
        case CONFIRM_RESTART_PROMPT_RESTART_LATER:
          createOrRemoveSpecialDevEditionFile();
          return;
      }
    }
  },

  onGetStarted: function (aEvent) {
    if (AppConstants.MOZ_DEV_EDITION) {
      const Cc = Components.classes, Ci = Components.interfaces;
      let wm = Cc["@mozilla.org/appshell/window-mediator;1"]
                  .getService(Ci.nsIWindowMediator);
      let win = wm.getMostRecentWindow("navigator:browser");

      if (win) {
        let accountsTab = win.gBrowser.addTab("about:accounts?action=signin&entrypoint=dev-edition-setup");
        win.gBrowser.selectedTab = accountsTab;
      }
    }
  },

  // HOME PAGE

  /*
   * Preferences:
   *
   * browser.startup.homepage
   * - the user's home page, as a string; if the home page is a set of tabs,
   *   this will be those URLs separated by the pipe character "|"
   * browser.startup.page
   * - what page(s) to show when the user starts the application, as an integer:
   *
   *     0: a blank page
   *     1: the home page (as set by the browser.startup.homepage pref)
   *     2: the last page the user visited (DEPRECATED)
   *     3: windows and tabs from the last session (a.k.a. session restore)
   *
   *   The deprecated option is not exposed in UI; however, if the user has it
   *   selected and doesn't change the UI for this preference, the deprecated
   *   option is preserved.
   */

  syncFromHomePref: function ()
  {
    let homePref = document.getElementById("browser.startup.homepage");

    // If the pref is set to about:home or about:newtab, set the value to ""
    // to show the placeholder text (about:home title) rather than
    // exposing those URLs to users.
    let defaultBranch = Services.prefs.getDefaultBranch("");
    let defaultValue = defaultBranch.getComplexValue("browser.startup.homepage",
                                                     Ci.nsIPrefLocalizedString).data;
    let currentValue = homePref.value.toLowerCase();
    if (currentValue == "about:home" ||
        (currentValue == defaultValue && currentValue == "about:newtab")) {
      return "";
    }

    // If the pref is actually "", show about:blank.  The actual home page
    // loading code treats them the same, and we don't want the placeholder text
    // to be shown.
    if (homePref.value == "")
      return "about:blank";

    // Otherwise, show the actual pref value.
    return undefined;
  },

  syncToHomePref: function (value)
  {
    // If the value is "", use about:home.
    if (value == "")
      return "about:home";

    // Otherwise, use the actual textbox value.
    return undefined;
  },

  /**
   * Sets the home page to the current displayed page (or frontmost tab, if the
   * most recent browser window contains multiple tabs), updating preference
   * window UI to reflect this.
   */
  setHomePageToCurrent: function ()
  {
    let homePage = document.getElementById("browser.startup.homepage");
    let tabs = this._getTabsForHomePage();
    function getTabURI(t) {
      return t.linkedBrowser.currentURI.spec;
    }

    // FIXME Bug 244192: using dangerous "|" joiner!
    if (tabs.length)
      homePage.value = tabs.map(getTabURI).join("|");
  },

  /**
   * Displays a dialog in which the user can select a bookmark to use as home
   * page.  If the user selects a bookmark, that bookmark's name is displayed in
   * UI and the bookmark's address is stored to the home page preference.
   */
  setHomePageToBookmark: function ()
  {
    var rv = { urls: null, names: null };
    gSubDialog.open("chrome://browser/content/preferences/selectBookmark.xul",
                    "resizable=yes, modal=yes", rv,
                    this._setHomePageToBookmarkClosed.bind(this, rv));
  },

  _setHomePageToBookmarkClosed: function(rv, aEvent) {
    if (aEvent.detail.button != "accept")
      return;
    if (rv.urls && rv.names) {
      var homePage = document.getElementById("browser.startup.homepage");

      // XXX still using dangerous "|" joiner!
      homePage.value = rv.urls.join("|");
    }
  },

  /**
   * Switches the "Use Current Page" button between its singular and plural
   * forms.
   */
  _updateUseCurrentButton: function () {
    let useCurrent = document.getElementById("useCurrent");


    let tabs = this._getTabsForHomePage();

    if (tabs.length > 1)
      useCurrent.label = useCurrent.getAttribute("label2");
    else
      useCurrent.label = useCurrent.getAttribute("label1");

    // In this case, the button's disabled state is set by preferences.xml.
    let prefName = "pref.browser.homepage.disable_button.current_page";
    if (document.getElementById(prefName).locked)
      return;

    useCurrent.disabled = !tabs.length
  },

  _getTabsForHomePage: function ()
  {
    var win;
    var tabs = [];

    const Cc = Components.classes, Ci = Components.interfaces;
    var wm = Cc["@mozilla.org/appshell/window-mediator;1"]
                .getService(Ci.nsIWindowMediator);
    win = wm.getMostRecentWindow("navigator:browser");

    if (win && win.document.documentElement
                  .getAttribute("windowtype") == "navigator:browser") {
      // We should only include visible & non-pinned tabs

      tabs = win.gBrowser.visibleTabs.slice(win.gBrowser._numPinnedTabs);
      tabs = tabs.filter(this.isNotAboutPreferences);
    }

    return tabs;
  },

  /**
   * Check to see if a tab is not about:preferences
   */
  isNotAboutPreferences: function (aElement, aIndex, aArray)
  {
    return !aElement.linkedBrowser.currentURI.spec.startsWith("about:preferences");
  },

  /**
   * Restores the default home page as the user's home page.
   */
  restoreDefaultHomePage: function ()
  {
    var homePage = document.getElementById("browser.startup.homepage");
    homePage.value = homePage.defaultValue;
  },

  // DOWNLOADS

  /*
   * Preferences:
   *
   * browser.download.useDownloadDir - bool
   *   True - Save files directly to the folder configured via the
   *   browser.download.folderList preference.
   *   False - Always ask the user where to save a file and default to
   *   browser.download.lastDir when displaying a folder picker dialog.
   * browser.download.dir - local file handle
   *   A local folder the user may have selected for downloaded files to be
   *   saved. Migration of other browser settings may also set this path.
   *   This folder is enabled when folderList equals 2.
   * browser.download.lastDir - local file handle
   *   May contain the last folder path accessed when the user browsed
   *   via the file save-as dialog. (see contentAreaUtils.js)
   * browser.download.folderList - int
   *   Indicates the location users wish to save downloaded files too.
   *   It is also used to display special file labels when the default
   *   download location is either the Desktop or the Downloads folder.
   *   Values:
   *     0 - The desktop is the default download location.
   *     1 - The system's downloads folder is the default download location.
   *     2 - The default download location is elsewhere as specified in
   *         browser.download.dir.
   * browser.download.downloadDir
   *   deprecated.
   * browser.download.defaultFolder
   *   deprecated.
   */

  /**
   * Enables/disables the folder field and Browse button based on whether a
   * default download directory is being used.
   */
  readUseDownloadDir: function ()
  {
    var downloadFolder = document.getElementById("downloadFolder");
    var chooseFolder = document.getElementById("chooseFolder");
    var preference = document.getElementById("browser.download.useDownloadDir");
    downloadFolder.disabled = !preference.value || preference.locked;
    chooseFolder.disabled = !preference.value || preference.locked;

    // don't override the preference's value in UI
    return undefined;
  },

  /**
   * Displays a file picker in which the user can choose the location where
   * downloads are automatically saved, updating preferences and UI in
   * response to the choice, if one is made.
   */
  chooseFolder()
  {
    return this.chooseFolderTask().catch(Components.utils.reportError);
  },
  chooseFolderTask: Task.async(function* ()
  {
    let bundlePreferences = document.getElementById("bundlePreferences");
    let title = bundlePreferences.getString("chooseDownloadFolderTitle");
    let folderListPref = document.getElementById("browser.download.folderList");
    let currentDirPref = yield this._indexToFolder(folderListPref.value);
    let defDownloads = yield this._indexToFolder(1);
    let fp = Components.classes["@mozilla.org/filepicker;1"].
             createInstance(Components.interfaces.nsIFilePicker);

    fp.init(window, title, Components.interfaces.nsIFilePicker.modeGetFolder);
    fp.appendFilters(Components.interfaces.nsIFilePicker.filterAll);
    // First try to open what's currently configured
    if (currentDirPref && currentDirPref.exists()) {
      fp.displayDirectory = currentDirPref;
    } // Try the system's download dir
    else if (defDownloads && defDownloads.exists()) {
      fp.displayDirectory = defDownloads;
    } // Fall back to Desktop
    else {
      fp.displayDirectory = yield this._indexToFolder(0);
    }

    let result = yield new Promise(resolve => fp.open(resolve));
    if (result != Components.interfaces.nsIFilePicker.returnOK) {
      return;
    }

    let downloadDirPref = document.getElementById("browser.download.dir");
    downloadDirPref.value = fp.file;
    folderListPref.value = yield this._folderToIndex(fp.file);
    // Note, the real prefs will not be updated yet, so dnld manager's
    // userDownloadsDirectory may not return the right folder after
    // this code executes. displayDownloadDirPref will be called on
    // the assignment above to update the UI.
  }),

  /**
   * Initializes the download folder display settings based on the user's
   * preferences.
   */
  displayDownloadDirPref()
  {
    this.displayDownloadDirPrefTask().catch(Components.utils.reportError);

    // don't override the preference's value in UI
    return undefined;
  },

  displayDownloadDirPrefTask: Task.async(function* ()
  {
    var folderListPref = document.getElementById("browser.download.folderList");
    var bundlePreferences = document.getElementById("bundlePreferences");
    var downloadFolder = document.getElementById("downloadFolder");
    var currentDirPref = document.getElementById("browser.download.dir");

    // Used in defining the correct path to the folder icon.
    var ios = Components.classes["@mozilla.org/network/io-service;1"]
                        .getService(Components.interfaces.nsIIOService);
    var fph = ios.getProtocolHandler("file")
                 .QueryInterface(Components.interfaces.nsIFileProtocolHandler);
    var iconUrlSpec;

    // Display a 'pretty' label or the path in the UI.
    if (folderListPref.value == 2) {
      // Custom path selected and is configured
      downloadFolder.label = this._getDisplayNameOfFile(currentDirPref.value);
      iconUrlSpec = fph.getURLSpecFromFile(currentDirPref.value);
    } else if (folderListPref.value == 1) {
      // 'Downloads'
      // In 1.5, this pointed to a folder we created called 'My Downloads'
      // and was available as an option in the 1.5 drop down. On XP this
      // was in My Documents, on OSX it was in User Docs. In 2.0, we did
      // away with the drop down option, although the special label was
      // still supported for the folder if it existed. Because it was
      // not exposed it was rarely used.
      // With 3.0, a new desktop folder - 'Downloads' was introduced for
      // platforms and versions that don't support a default system downloads
      // folder. See nsDownloadManager for details.
      downloadFolder.label = bundlePreferences.getString("downloadsFolderName");
      iconUrlSpec = fph.getURLSpecFromFile(yield this._indexToFolder(1));
    } else {
      // 'Desktop'
      downloadFolder.label = bundlePreferences.getString("desktopFolderName");
      iconUrlSpec = fph.getURLSpecFromFile(yield this._getDownloadsFolder("Desktop"));
    }
    downloadFolder.image = "moz-icon://" + iconUrlSpec + "?size=16";
  }),

  /**
   * Returns the textual path of a folder in readable form.
   */
  _getDisplayNameOfFile: function (aFolder)
  {
    // TODO: would like to add support for 'Downloads on Macintosh HD'
    //       for OS X users.
    return aFolder ? aFolder.path : "";
  },

  /**
   * Returns the Downloads folder.  If aFolder is "Desktop", then the Downloads
   * folder returned is the desktop folder; otherwise, it is a folder whose name
   * indicates that it is a download folder and whose path is as determined by
   * the XPCOM directory service via the download manager's attribute
   * defaultDownloadsDirectory.
   *
   * @throws if aFolder is not "Desktop" or "Downloads"
   */
  _getDownloadsFolder: Task.async(function* (aFolder)
  {
    switch (aFolder) {
      case "Desktop":
        var fileLoc = Components.classes["@mozilla.org/file/directory_service;1"]
                                    .getService(Components.interfaces.nsIProperties);
        return fileLoc.get("Desk", Components.interfaces.nsILocalFile);
      case "Downloads":
        let downloadsDir = yield Downloads.getSystemDownloadsDirectory();
        return new FileUtils.File(downloadsDir);
    }
    throw "ASSERTION FAILED: folder type should be 'Desktop' or 'Downloads'";
  }),

  /**
   * Determines the type of the given folder.
   *
   * @param   aFolder
   *          the folder whose type is to be determined
   * @returns integer
   *          0 if aFolder is the Desktop or is unspecified,
   *          1 if aFolder is the Downloads folder,
   *          2 otherwise
   */
  _folderToIndex: Task.async(function* (aFolder)
  {
    if (!aFolder || aFolder.equals(yield this._getDownloadsFolder("Desktop")))
      return 0;
    else if (aFolder.equals(yield this._getDownloadsFolder("Downloads")))
      return 1;
    return 2;
  }),

  /**
   * Converts an integer into the corresponding folder.
   *
   * @param   aIndex
   *          an integer
   * @returns the Desktop folder if aIndex == 0,
   *          the Downloads folder if aIndex == 1,
   *          the folder stored in browser.download.dir
   */
  _indexToFolder: Task.async(function* (aIndex)
  {
    switch (aIndex) {
      case 0:
        return yield this._getDownloadsFolder("Desktop");
      case 1:
        return yield this._getDownloadsFolder("Downloads");
    }
    var currentDirPref = document.getElementById("browser.download.dir");
    return currentDirPref.value;
  }),

  /**
   * Hide/show the "Show my windows and tabs from last time" option based
   * on the value of the browser.privatebrowsing.autostart pref.
   */
  updateBrowserStartupLastSession: function()
  {
    let pbAutoStartPref = document.getElementById("browser.privatebrowsing.autostart");
    let startupPref = document.getElementById("browser.startup.page");
    let menu = document.getElementById("browserStartupPage");
    let option = document.getElementById("browserStartupLastSession");
    if (pbAutoStartPref.value) {
      option.setAttribute("disabled", "true");
      if (option.selected) {
        menu.selectedItem = document.getElementById("browserStartupHomePage");
      }
    } else {
      option.removeAttribute("disabled");
      startupPref.updateElements(); // select the correct index in the startup menulist
    }
  },

  // TABS

  /*
   * Preferences:
   *
   * browser.link.open_newwindow - int
   *   Determines where links targeting new windows should open.
   *   Values:
   *     1 - Open in the current window or tab.
   *     2 - Open in a new window.
   *     3 - Open in a new tab in the most recent window.
   * browser.tabs.loadInBackground - bool
   *   True - Whether browser should switch to a new tab opened from a link.
   * browser.tabs.warnOnClose - bool
   *   True - If when closing a window with multiple tabs the user is warned and
   *          allowed to cancel the action, false to just close the window.
   * browser.tabs.warnOnOpen - bool
   *   True - Whether the user should be warned when trying to open a lot of
   *          tabs at once (e.g. a large folder of bookmarks), allowing to
   *          cancel the action.
   * browser.taskbar.previews.enable - bool
   *   True - Tabs are to be shown in Windows 7 taskbar.
   *   False - Only the window is to be shown in Windows 7 taskbar.
   */

  /**
   * Determines where a link which opens a new window will open.
   *
   * @returns |true| if such links should be opened in new tabs
   */
  readLinkTarget: function() {
    var openNewWindow = document.getElementById("browser.link.open_newwindow");
    return openNewWindow.value != 2;
  },

  /**
   * Determines where a link which opens a new window will open.
   *
   * @returns 2 if such links should be opened in new windows,
   *          3 if such links should be opened in new tabs
   */
  writeLinkTarget: function() {
    var linkTargeting = document.getElementById("linkTargeting");
    return linkTargeting.checked ? 3 : 2;
  },
  /*
   * Preferences:
   *
   * browser.shell.checkDefault
   * - true if a default-browser check (and prompt to make it so if necessary)
   *   occurs at startup, false otherwise
   */

  /**
   * Show button for setting browser as default browser or information that
   * browser is already the default browser.
   */
  updateSetDefaultBrowser: function()
  {
    if (AppConstants.HAVE_SHELL_SERVICE) {
      let shellSvc = getShellService();
      let defaultBrowserBox = document.getElementById("defaultBrowserBox");
      if (!shellSvc) {
        defaultBrowserBox.hidden = true;
        return;
      }
      let setDefaultPane = document.getElementById("setDefaultPane");
      let isDefault = shellSvc.isDefaultBrowser(false, true);
      setDefaultPane.selectedIndex = isDefault ? 1 : 0;
      let alwaysCheck = document.getElementById("alwaysCheckDefault");
      alwaysCheck.disabled = alwaysCheck.disabled ||
                             isDefault && alwaysCheck.checked;
    }
  },

  /**
   * Set browser as the operating system default browser.
   */
  setDefaultBrowser: function()
  {
    if (AppConstants.HAVE_SHELL_SERVICE) {
      let alwaysCheckPref = document.getElementById("browser.shell.checkDefaultBrowser");
      alwaysCheckPref.value = true;

      let shellSvc = getShellService();
      if (!shellSvc)
        return;
      try {
        shellSvc.setDefaultBrowser(true, false);
      } catch (ex) {
        Cu.reportError(ex);
        return;
      }

      let selectedIndex = shellSvc.isDefaultBrowser(false, true) ? 1 : 0;
      document.getElementById("setDefaultPane").selectedIndex = selectedIndex;
    }
  },
};