js: Remove unnecessary versions of clutter_actor_get_children

clutter_actor_get_children requires making a temporary GSList from
a linked list structure, and then creating a JS Array from that GSList.
For simple cases like the number of children, use clutter_actor_get_n_children.

https://bugzilla.gnome.org/show_bug.cgi?id=677426

js/ui/calendar.js

@@ -448,7 +448,7 @@ const Calendar = new Lang.Class({
         }
 
         // All the children after this are days, and get removed when we update the calendar
-        this._firstDayIndex = this.actor.get_children().length;
+        this._firstDayIndex = this.actor.get_n_children();
     },
 
     _onStyleChange: function(actor, event) {

js/ui/endSessionDialog.js

@@ -31,7 +31,6 @@ const St = imports.gi.St;
 const Shell = imports.gi.Shell;
 
 const GnomeSession = imports.misc.gnomeSession;
-const Lightbox = imports.ui.lightbox;
 const Main = imports.ui.main;
 const ModalDialog = imports.ui.modalDialog;
 const Tweener = imports.ui.tweener;
@@ -288,13 +287,13 @@ const EndSessionDialog = new Lang.Class({
 
         this._applicationList.connect('actor-added',
                                       Lang.bind(this, function() {
-                                          if (this._applicationList.get_children().length == 1)
+                                          if (this._applicationList.get_n_children() == 1)
                                               scrollView.show();
                                       }));
 
         this._applicationList.connect('actor-removed',
                                       Lang.bind(this, function() {
-                                          if (this._applicationList.get_children().length == 0)
+                                          if (this._applicationList.get_n_children() == 0)
                                               scrollView.hide();
                                       }));
 

js/ui/iconGrid.js

@@ -310,9 +310,7 @@ const IconGrid = new Lang.Class({
     },
 
     removeAll: function() {
-        this._grid.get_children().forEach(Lang.bind(this, function (child) {
+        this._grid.destroy_all_children();
-            child.destroy();
-        }));
     },
 
     addItem: function(actor) {
@@ -320,10 +318,10 @@ const IconGrid = new Lang.Class({
     },
 
     getItemAtIndex: function(index) {
-        return this._grid.get_children()[index];
+        return this._grid.get_child_at_index(index);
     },
 
     visibleItemsCount: function() {
-        return this._grid.get_children().length - this._grid.get_n_skip_paint();
+        return this._grid.get_n_children() - this._grid.get_n_skip_paint();
     }
 });

js/ui/lookingGlass.js

@@ -320,7 +320,7 @@ const WindowList = new Lang.Class({
     },
 
     _updateWindowList: function() {
-        this.actor.get_children().forEach(function (actor) { actor.destroy(); });
+        this.actor.destroy_all_children();
         let windows = global.get_window_actors();
         let tracker = Shell.WindowTracker.get_default();
         for (let i = 0; i < windows.length; i++) {
@@ -378,7 +378,7 @@ const ObjInspector = new Lang.Class({
             this._previousObj = null;
         this._obj = obj;
 
-        this._container.get_children().forEach(function (child) { child.destroy(); });
+        this._container.destroy_all_children();
 
         let hbox = new St.BoxLayout({ style_class: 'lg-obj-inspector-title' });
         this._container.add_actor(hbox);

js/ui/messageTray.js

@@ -756,7 +756,7 @@ const Notification = new Lang.Class({
             button.label = label;
         }
 
-        if (this._buttonBox.get_children().length > 0)
+        if (this._buttonBox.get_n_children() > 0)
             this._buttonFocusManager.remove_group(this._buttonBox);
 
         this._buttonBox.add(button);
@@ -1284,7 +1284,7 @@ const SummaryItem = new Lang.Class({
     },
 
     prepareNotificationStackForShowing: function() {
-        if (this.notificationStack.get_children().length > 0)
+        if (this.notificationStack.get_n_children() > 0)
             return;
 
         for (let i = 0; i < this.source.notifications.length; i++) {
@@ -1293,7 +1293,6 @@ const SummaryItem = new Lang.Class({
     },
 
     doneShowingNotificationStack: function() {
-        let notificationActors = this.notificationStack.get_children();
         for (let i = 0; i < this._stackedNotifications.length; i++) {
             let stackedNotification = this._stackedNotifications[i];
             let notification = stackedNotification.notification;
@@ -1323,7 +1322,7 @@ const SummaryItem = new Lang.Class({
         this._stackedNotifications.push(stackedNotification);
         if (!this.source.isChat)
             notification.enableScrolling(false);
-        if (this.notificationStack.get_children().length > 0)
+        if (this.notificationStack.get_n_children() > 0)
             notification.setIconVisible(false);
         this.notificationStack.add(notification.actor);
         notification.expand(false);
@@ -2436,7 +2435,7 @@ const MessageTray = new Lang.Class({
     },
 
     _onSummaryBoxPointerContentUpdated: function() {
-        if (this._summaryBoxPointerItem.notificationStack.get_children().length == 0)
+        if (this._summaryBoxPointerItem.notificationStack.get_n_children() == 0)
             this._hideSummaryBoxPointer();
         this._adjustSummaryBoxPointerPosition();
 
@@ -2470,7 +2469,7 @@ const MessageTray = new Lang.Class({
         // We should be sure to hide the box pointer if all notifications in it are destroyed while
         // it is hiding, so that we don't show an an animation of an empty blob being hidden.
         if (this._summaryBoxPointerState == State.HIDING &&
-            this._summaryBoxPointerItem.notificationStack.get_children().length == 0) {
+            this._summaryBoxPointerItem.notificationStack.get_n_children() == 0) {
             this._summaryBoxPointer.actor.hide();
             return;
         }

js/ui/overview.js

@@ -14,7 +14,6 @@ const AppDisplay = imports.ui.appDisplay;
 const ContactDisplay = imports.ui.contactDisplay;
 const Dash = imports.ui.dash;
 const DND = imports.ui.dnd;
-const Lightbox = imports.ui.lightbox;
 const Main = imports.ui.main;
 const MessageTray = imports.ui.messageTray;
 const Panel = imports.ui.panel;

js/ui/popupMenu.js

@@ -906,7 +906,7 @@ const PopupMenuBase = new Lang.Class({
     },
 
     isEmpty: function() {
-        return this.box.get_children().length == 0;
+        return this.box.get_n_children() == 0;
     },
 
     isChildMenu: function(menu) {

js/ui/search.js

@@ -51,7 +51,7 @@ const SearchResultDisplay = new Lang.Class({
      * Remove all results from this display.
      */
     clear: function() {
-        this.actor.get_children().forEach(function (actor) { actor.destroy(); });
+        this.actor.destroy_all_children();
     },
 
     /**

js/ui/shellMountOperation.js

@@ -347,13 +347,13 @@ const ShellProcessesDialog = new Lang.Class({
 
         this._applicationList.connect('actor-added',
                                       Lang.bind(this, function() {
-                                          if (this._applicationList.get_children().length == 1)
+                                          if (this._applicationList.get_n_children() == 1)
                                               scrollView.show();
                                       }));
 
         this._applicationList.connect('actor-removed',
                                       Lang.bind(this, function() {
-                                          if (this._applicationList.get_children().length == 0)
+                                          if (this._applicationList.get_n_children() == 0)
                                               scrollView.hide();
                                       }));
     },

js/ui/telepathyClient.js

@@ -802,7 +802,7 @@ const ChatNotification = new Lang.Class({
         let groups = this._contentArea.get_children();
         for (let i = 0; i < groups.length; i++) {
             let group = groups[i];
-            if (group.get_children().length == 0)
+            if (group.get_n_children() == 0)
                 group.destroy();
         }
     },