[gnome-documents] mainToolbar: Disable headerbar controls when there are no documents

[Debarshi Ray <debarshir src gnome org>]

commit e97245fa35b2bf9b525ed736574d71e0404f6d2d
Author: Alessandro Bono <abono gnome org>
Date:   Sat Nov 7 16:06:41 2015 +0100

    mainToolbar: Disable headerbar controls when there are no documents
    
    https://bugzilla.gnome.org/show_bug.cgi?id=756014

 src/mainToolbar.js |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/src/mainToolbar.js b/src/mainToolbar.js
index e249536..174e15c 100644
--- a/src/mainToolbar.js
+++ b/src/mainToolbar.js
@@ -114,6 +114,7 @@ const OverviewToolbar = new Lang.Class({
         this._viewSettingsId = 0;
         this._activeCollection = null;
         this._infoUpdatedId = 0;
+        this._countChangedId = 0;
 
         this.parent();
 
@@ -286,6 +287,11 @@ const OverviewToolbar = new Lang.Class({
         this._viewMenuButton = null;
         this.toolbar.set_custom_title(null);
 
+        if (this._countChangedId != 0) {
+            Application.offsetDocumentsController.disconnect(this._countChangedId);
+            this._countChangedId = 0;
+        }
+
         if (this._collectionId != 0) {
             Application.documentManager.disconnect(this._collectionId);
             this._collectionId = 0;
@@ -323,6 +329,14 @@ const OverviewToolbar = new Lang.Class({
         this._setToolbarTitle();
         this.toolbar.show_all();
 
+        this._countChangedId = Application.offsetDocumentsController.connect('item-count-changed', 
Lang.bind(this,
+            function(controller, count) {
+                this.toolbar.foreach(Lang.bind(this,
+                    function(child) {
+                        child.set_sensitive(count != 0);
+                    }));
+            }));
+
         if (Application.searchController.getString() != '')
             Application.application.change_action_state('search', GLib.Variant.new('b', true));
     },