[gtk] widget factory: add a tooltip to a button in a popover

[Timm Bäder <baedert src gnome org>]

commit 20d7b7f59b501c3989c0c01958b013f9d74c2b88
Author: Timm Bäder <mail baedert org>
Date:   Tue Jul 30 07:05:45 2019 +0200

    widget factory: add a tooltip to a button in a popover

 demos/widget-factory/widget-factory.ui | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/demos/widget-factory/widget-factory.ui b/demos/widget-factory/widget-factory.ui
index 110e62e1a1..c861a6f475 100644
--- a/demos/widget-factory/widget-factory.ui
+++ b/demos/widget-factory/widget-factory.ui
@@ -3435,6 +3435,7 @@ bad things might happen.</property>
             <property name="halign">end</property>
             <property name="icon-name">emblem-system-symbolic</property>
             <property name="menu-model">gear_menu</property>
+            <property name="tooltip-text">This is a menu button</property>
             <layout>
               <property name="left-attach">1</property>
               <property name="top-attach">3</property>