[gnome-contacts] Use DBus to open the Online Accounts panel.

[Niels De Graef <nielsdg src gnome org>]

commit d03f268fc5ff3bb0a372ff2a23995e411e16c5cd
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Wed Aug 23 11:44:20 2017 +0200

    Use DBus to open the Online Accounts panel.
    
    Can't spawn processes in a sandboxed environment (Flatpak), so use DBus
    insteads.

 data/flatpak/org.gnome.Contacts.json |    2 ++
 src/contacts-accounts-list.vala      |   21 +++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)
---
diff --git a/data/flatpak/org.gnome.Contacts.json b/data/flatpak/org.gnome.Contacts.json
index 9101eab..67213c6 100644
--- a/data/flatpak/org.gnome.Contacts.json
+++ b/data/flatpak/org.gnome.Contacts.json
@@ -16,6 +16,8 @@
         "--device=dri",
         /* Notification access */
         "--talk-name=org.freedesktop.Notifications",
+        /* GNOME Control Center (for the Online Accounts panel) */
+        "--talk-name=org.gnome.ControlCenter",
         /* GNOME Online Accounts */
         "--talk-name=org.gnome.OnlineAccounts",
         /* Evolution Data server */
diff --git a/src/contacts-accounts-list.vala b/src/contacts-accounts-list.vala
index e742819..652b26e 100644
--- a/src/contacts-accounts-list.vala
+++ b/src/contacts-accounts-list.vala
@@ -154,10 +154,27 @@ public class Contacts.AccountsList : Box {
   [GtkCallback]
   private void on_goa_button_clicked () {
     try {
-      Process.spawn_command_line_async ("gnome-control-center online-accounts");
+      var proxy = new DBusProxy.for_bus_sync (BusType.SESSION,
+                                              DBusProxyFlags.NONE,
+                                              null,
+                                              "org.gnome.ControlCenter",
+                                              "/org/gnome/ControlCenter",
+                                              "org.gtk.Actions");
+
+      var builder = new VariantBuilder (new VariantType ("av") );
+      builder.add ("v", new Variant.string (""));
+      var param = new Variant.tuple ({
+        new Variant.string ("launch-panel"),
+        new Variant.array (new VariantType ("v"), {
+          new Variant ("v", new Variant ("(sav)", "online-accounts", builder))
+        }),
+        new Variant.array (new VariantType ("{sv}"), {})
+      });
+
+      proxy.call_sync ("Activate", param, DBusCallFlags.NONE, -1);
     } catch (Error e) {
       // TODO: Show error dialog
-      warning ("Couldn't open GOA: %s", e.message);
+      warning ("Couldn't open online-accounts: %s", e.message);
     }
   }
 }