[sushi: 2/3] Export a Visible property over D-Bus

[Cosimo Cecchi <cosimoc src gnome org>]

commit 30ec9b835cadfb6e95cc87fc376e65f5946d3b23
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Sat Jul 6 22:57:53 2019 -0700

    Export a Visible property over D-Bus
    
    This is needed to help Nautilus update the preview file when we're
    open and its selection change.
    
    https://gitlab.gnome.org/GNOME/sushi/issues/5

 src/org.gnome.NautilusPreviewer2.xml | 1 +
 src/ui/application.js                | 5 +++++
 2 files changed, 6 insertions(+)
---
diff --git a/src/org.gnome.NautilusPreviewer2.xml b/src/org.gnome.NautilusPreviewer2.xml
index c9f0baa..e22072b 100644
--- a/src/org.gnome.NautilusPreviewer2.xml
+++ b/src/org.gnome.NautilusPreviewer2.xml
@@ -7,6 +7,7 @@
     </method>
     <method name="Close">
     </method>
+    <property name="Visible" type="b" access="read" />
     <signal name="SelectionEvent">
       <arg type="q" name="direction" />
     </signal>
diff --git a/src/ui/application.js b/src/ui/application.js
index ba96031..53fe2b4 100644
--- a/src/ui/application.js
+++ b/src/ui/application.js
@@ -113,8 +113,13 @@ var Application = GObject.registerClass(class Application extends Gtk.Applicatio
             return;
 
         this._mainWindow = new MainWindow.MainWindow(this);
+        this._skeleton2.impl.emit_property_changed(
+            'Visible', new GLib.Variant('b', true));
+
         this._mainWindow.connect('destroy', () => {
             this._mainWindow = null;
+            this._skeleton2.impl.emit_property_changed(
+                'Visible', new GLib.Variant('b', false));
         });
     }