Sort GtkApplication windows by most-recently-focused

Based on a patch by Matt Barnes,
https://bugzilla.gnome.org/show_bug.cgi?id=624539

1 files changed, 37 insertions, 3 deletions

diff --git a/gtk/gtkapplication.c b/gtk/gtkapplication.c
index cf57bf28f5..d6287d9c9b 100644
--- a/gtk/gtkapplication.c
+++ b/gtk/gtkapplication.c
@@ -67,6 +67,25 @@ struct _GtkApplicationPrivate
   GList *windows;
 };
 
+static gboolean
+gtk_application_focus_in_event_cb (GtkWindow      *window,
+                                   GdkEventFocus  *event,
+                                   GtkApplication *application)
+{
+  GtkApplicationPrivate *priv = application->priv;
+  GList *link;
+
+  /* Keep the window list sorted by most-recently-focused. */
+  link = g_list_find (priv->windows, window);
+  if (link != NULL && link != priv->windows)
+    {
+      priv->windows = g_list_remove_link (priv->windows, link);
+      priv->windows = g_list_concat (link, priv->windows);
+    }
+
+  return FALSE;
+}
+
 static void
 gtk_application_startup (GApplication *application)
 {
@@ -216,6 +235,10 @@ gtk_application_add_window (GtkApplication *application,
       priv->windows = g_list_prepend (priv->windows, window);
       gtk_window_set_application (window, application);
       g_application_hold (G_APPLICATION (application));
+
+      g_signal_connect (window, "focus-in-event",
+                        G_CALLBACK (gtk_application_focus_in_event_cb),
+                        application);
     }
 }
 
@@ -240,13 +263,18 @@ gtk_application_remove_window (GtkApplication *application,
                                GtkWindow      *window)
 {
   GtkApplicationPrivate *priv;
+  GList *link;
 
   g_return_if_fail (GTK_IS_APPLICATION (application));
 
   priv = application->priv;
-  if (g_list_find (priv->windows, window))
+  link = g_list_find (priv->windows, window);
+  if (link)
     {
-      priv->windows = g_list_remove (priv->windows, window);
+      g_signal_handlers_disconnect_by_func (window,
+                                            gtk_application_focus_in_event_cb,
+                                            application);
+      priv->windows = g_list_remove_link (priv->windows, link);
       g_application_release (G_APPLICATION (application));
       gtk_window_set_application (window, NULL);
     }
@@ -258,7 +286,13 @@ gtk_application_remove_window (GtkApplication *application,
  *
  * Gets a list of the #GtkWindow<!-- -->s associated with @application.
  *
- * The list that is returned should not be modified in any way.
+ * The list is sorted by most recently focused window, such that the first
+ * element is the currently focused window.  (Useful for choosing a parent
+ * for a transient window.)
+ *
+ * The list that is returned should not be modified in any way. It will
+ * only remain valid until the next focus change or window creation or
+ * deletion.
  *
  * Returns: (element-type GtkWindow) (transfer none): a #GList of #GtkWindow
  *