appDisplay: Separate app loading from filling the grid

At the moment when loading the applications, each app is inserted
at its correct (alphabetical) position. Avoid this overhead by
loading all apps first, then sort them once and fill the grid with
the sorted actors.

https://bugzilla.gnome.org/show_bug.cgi?id=694192

js/ui/appDisplay.js

@@ -89,12 +89,21 @@ const AlphabeticalView = new Lang.Class({
             return null;
 
         let itemIcon = this._createItemIcon(item);
-        let pos = Util.insertSorted(this._allItems, item, this._compareItems);
+        this._allItems.push(item);
-        this._grid.addItem(itemIcon.actor, pos);
-
         this._items[id] = itemIcon;
 
         return itemIcon;
+    },
+
+    loadGrid: function() {
+        this._allItems.sort(this._compareItems);
+
+        for (let i = 0; i < this._allItems.length; i++) {
+            let id = this._getItemId(this._allItems[i]);
+            if (!id)
+                continue;
+            this._grid.addItem(this._items[id].actor);
+        }
     }
 });
 
@@ -276,6 +285,7 @@ const AppDisplay = new Lang.Class({
                 _loadCategory(dir, this._view);
             }
         }
+        this._view.loadGrid();
 
         if (this._focusDummy) {
             let focused = this._focusDummy.has_key_focus();
@@ -367,6 +377,7 @@ const FolderIcon = new Lang.Class({
         this.view = new FolderView();
         this.view.actor.reactive = false;
         _loadCategory(dir, this.view);
+        this.view.loadGrid();
 
         this.actor.connect('clicked', Lang.bind(this,
             function() {