[gnome-games] header-bar: Add display_back() signal

[Adrien Plazas <aplazas src gnome org>]

commit 13542bf385805cfb5c5d6aec90f1dc9f3e466a54
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sun Mar 6 19:40:56 2016 +0100

    header-bar: Add display_back() signal
    
    This will be used to let the application window check if we can safely
    quit the game when going back to the collection.

 src/ui/application-window.vala |    4 ++++
 src/ui/header-bar.vala         |    4 +++-
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/src/ui/application-window.vala b/src/ui/application-window.vala
index b434f26..1a62cd4 100644
--- a/src/ui/application-window.vala
+++ b/src/ui/application-window.vala
@@ -50,6 +50,10 @@ private class Games.ApplicationWindow : Gtk.ApplicationWindow {
                                                               this, "search-mode", 
BindingFlags.BIDIRECTIONAL);
                hb_search_binding = header_bar.bind_property ("search-mode",
                                                              this, "search-mode", 
BindingFlags.BIDIRECTIONAL);
+
+               header_bar.display_back.connect (() => {
+                       ui_state = UiState.COLLECTION;
+               });
        }
 
        [GtkCallback]
diff --git a/src/ui/header-bar.vala b/src/ui/header-bar.vala
index b972f30..3662653 100644
--- a/src/ui/header-bar.vala
+++ b/src/ui/header-bar.vala
@@ -2,6 +2,8 @@
 
 [GtkTemplate (ui = "/org/gnome/Games/ui/header-bar.ui")]
 private class Games.HeaderBar : Gtk.Stack {
+       public signal void display_back ();
+
        private UiState _ui_state;
        public UiState ui_state {
                set {
@@ -47,6 +49,6 @@ private class Games.HeaderBar : Gtk.Stack {
 
        [GtkCallback]
        private void on_display_back_clicked () {
-               ui_state = UiState.COLLECTION;
+               display_back ();
        }
 }