use the singleton construction idiom to create vimperator.tabs

content/commands.js

@@ -1934,7 +1934,7 @@ vimperator.Commands = function () //{{{
             else if (/^\d+$/.test(args))
             {
                 var index = parseInt(args, 10) - 1;
-                if (index < vimperator.tabs.count())
+                if (index < vimperator.tabs.count)
                     vimperator.tabs.select(index, true);
                 else
                     vimperator.beep();

content/mappings.js

@@ -552,7 +552,7 @@ vimperator.Mappings = function () //{{{
     addDefaultMap(new vimperator.Map([vimperator.modes.NORMAL], ["<C-^>", "<C-6>"],
         function ()
         {
-            if (vimperator.tabs.getTab() == vimperator.tabs.alternate)
+            if (vimperator.tabs.alternate == null || vimperator.tabs.getTab() == vimperator.tabs.alternate)
             {
                 vimperator.echoerr("E23: No alternate page");
                 return;

content/tabs.js

@@ -38,13 +38,12 @@ vimperator.Tabs = function () //{{{
     ////////////////////// PRIVATE SECTION /////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{
 
-    /** @param spec can either be:
+    // @param spec can either be:
-     * - an absolute integer
+    // - an absolute integer
-     * - "" for the current tab
+    // - "" for the current tab
-     * - "+1" for the next tab
+    // - "+1" for the next tab
-     * - "-3" for the tab, which is 3 positions left of the current
+    // - "-3" for the tab, which is 3 positions left of the current
-     * - "$" for the last tab
+    // - "$" for the last tab
-     */
     function indexFromSpec(spec, wrap)
     {
         var position = getBrowser().tabContainer.selectedIndex;
@@ -80,14 +79,20 @@ vimperator.Tabs = function () //{{{
         return position;
     }
 
-    var alternates = [null, null];
+    var alternates = [getBrowser().mCurrentTab, null];
 
     /////////////////////////////////////////////////////////////////////////////}}}
     ////////////////////// PUBLIC SECTION //////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{
 
+    return {
+
+        get alternate() { return alternates[1]; },
+
+        get count() { return getBrowser().mTabs.length; },
+
         // @returns the index of the currently selected tab starting with 0
-    this.index = function (tab)
+        index: function (tab)
         {
             if (tab)
             {
@@ -101,16 +106,11 @@ vimperator.Tabs = function () //{{{
             }
 
             return getBrowser().tabContainer.selectedIndex;
-    };
+        },
-
-    this.count = function ()
-    {
-        return getBrowser().mTabs.length;
-    };
 
         // TODO: implement filter
         // @returns an array of tabs which match filter
-    this.get = function (filter)
+        get: function (filter)
         {
             var buffers = [];
             var browsers = getBrowser().browsers;
@@ -122,34 +122,32 @@ vimperator.Tabs = function () //{{{
                 buffers.push([number, title, uri]);
             }
             return buffers;
-    };
+        },
 
-    this.getTab = function (index)
+        getTab: function (index)
         {
             if (index)
                 return getBrowser().mTabs[index];
 
             return getBrowser().tabContainer.selectedItem;
-    };
+        },
 
-    /*  spec == "" moves the tab to the last position as per Vim
+        // spec == "" moves the tab to the last position as per Vim
-     *  wrap causes the movement to wrap around the start and end of the tab list
+        // wrap causes the movement to wrap around the start and end of the tab list
-     *  NOTE: position is a 0 based index
+        // NOTE: position is a 0 based index
-     *  FIXME: tabmove! N should probably produce an error
+        // FIXME: tabmove! N should probably produce an error
-     */
+        move: function (tab, spec, wrap)
-    this.move = function (tab, spec, wrap)
         {
             if (spec === "")
                 spec = "$"; // if not specified, move to the last tab -> XXX: move to ex handling?
 
             var index = indexFromSpec(spec, wrap);
             getBrowser().moveTabTo(tab, index);
-    };
+        },
 
-    /* quit_on_last_tab = 1: quit without saving session
+        // quit_on_last_tab = 1: quit without saving session
-     * quit_on_last_tab = 2: quit and save session
+        // quit_on_last_tab = 2: quit and save session
-     */
+        remove: function (tab, count, focus_left_tab, quit_on_last_tab)
-    this.remove = function (tab, count, focus_left_tab, quit_on_last_tab)
         {
             function removeOrBlankTab (tab)
             {
@@ -195,20 +193,20 @@ vimperator.Tabs = function () //{{{
             else
             {
                 var i = index + count - 1;
-            if (i >= this.count())
+                if (i >= this.count)
-                i = this.count() - 1;
+                    i = this.count - 1;
 
                 for (; i >= index; i--)
                     removeOrBlankTab(this.getTab(i));
             }
-    };
+        },
 
-    this.keepOnly = function (tab)
+        keepOnly: function (tab)
         {
             getBrowser().removeAllTabsBut(tab);
-    };
+        },
 
-    this.select = function (spec, wrap)
+        select: function (spec, wrap)
         {
             var index = indexFromSpec(spec, wrap);
             if (index === false)
@@ -217,22 +215,18 @@ vimperator.Tabs = function () //{{{
                 return false;
             }
             getBrowser().mTabContainer.selectedIndex = index;
-    };
+        },
 
         // TODO: when restarting a session FF selects the first tab and then the
         // tab that was selected when the session was created.  As a result the
         // alternate after a restart is often incorrectly tab 1 when there
         // shouldn't be one yet.
-    this.updateSelectionHistory = function ()
+        updateSelectionHistory: function ()
         {
             alternates = [this.getTab(), alternates[0]];
-        this.alternate = alternates[1];
+        },
-    };
 
-    // TODO: move to v.buffers
+        reload: function (tab, bypass_cache)
-    this.alternate = this.getTab();
-
-    this.reload = function (tab, bypass_cache)
         {
             if (bypass_cache)
             {
@@ -244,9 +238,9 @@ vimperator.Tabs = function () //{{{
             {
                 getBrowser().reloadTab(tab);
             }
-    };
+        },
 
-    this.reloadAll = function (bypass_cache)
+        reloadAll: function (bypass_cache)
         {
             if (bypass_cache)
             {
@@ -267,6 +261,8 @@ vimperator.Tabs = function () //{{{
             {
                 getBrowser().reloadAllTabs();
             }
+        }
+
     };
     //}}}
 }; //}}}

content/ui.js

@@ -1184,7 +1184,7 @@ vimperator.StatusLine = function () //{{{
             if (!cur_index || typeof cur_index != "number")
                 cur_index = vimperator.tabs.index() + 1;
             if (!total_tabs || typeof cur_index != "number")
-                total_tabs = vimperator.tabs.count();
+                total_tabs = vimperator.tabs.count;
 
             tabcount_widget.value = "[" + cur_index + "/" + total_tabs + "]";
         },

content/vimperator.js

@@ -245,9 +245,12 @@ const vimperator = (function () //{{{
 
             var string = "";
             var obj = "";
-            try { // for window.JSON
+            try
+            { // for window.JSON
                 obj = object.toString();
-            } catch (e) {
+            }
+            catch (e)
+            {
                 obj = "<Object>";
             }
 
@@ -604,7 +607,7 @@ const vimperator = (function () //{{{
             vimperator.log("Loading module editor...", 3);
             vimperator.editor        = vimperator.Editor();
             vimperator.log("Loading module tabs...", 3);
-            vimperator.tabs          = new vimperator.Tabs();
+            vimperator.tabs          = vimperator.Tabs();
             vimperator.log("Loading module marks...", 3);
             vimperator.marks         = vimperator.Marks();
             vimperator.log("Loading module quickmarks...", 3);