Close window overview when last window is closed (#2430)

Author: lenemter

src/Widgets/MultitaskingView/WindowCloneContainer.vala

@@ -10,6 +10,7 @@
 public class Gala.WindowCloneContainer : ActorTarget {
     public signal void window_selected (Meta.Window window);
     public signal void requested_close ();
+    public signal void last_window_closed ();
 
     public int padding_top { get; set; default = 12; }
     public int padding_left { get; set; default = 12; }
@@ -105,6 +106,10 @@ public class Gala.WindowCloneContainer : ActorTarget {
                 break;
             }
         }
+
+        if (get_n_children () == 0) {
+            last_window_closed ();
+        }
     }
 
     /**

src/Widgets/WindowOverview.vala

@@ -134,6 +134,7 @@ public class Gala.WindowOverview : ActorTarget, RootTarget, ActivatableComponent
             };
             window_clone_container.window_selected.connect (thumb_selected);
             window_clone_container.requested_close.connect (() => close ());
+            window_clone_container.last_window_closed.connect (() => close ());
 
             add_child (window_clone_container);
         }