[gnome-builder] glade: fix transition between glade design and source view

[Christian Hergert <chergert src gnome org>]

commit 4e193881038539826f29f5d94a622abbae0c1dff
Author: Christian Hergert <chergert redhat com>
Date:   Wed Apr 10 23:25:06 2019 -0700

    glade: fix transition between glade design and source view
    
    Fixes #881

 src/plugins/glade/gbp-glade-frame-addin.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/src/plugins/glade/gbp-glade-frame-addin.c b/src/plugins/glade/gbp-glade-frame-addin.c
index e7349399f..8751a6269 100644
--- a/src/plugins/glade/gbp-glade-frame-addin.c
+++ b/src/plugins/glade/gbp-glade-frame-addin.c
@@ -237,6 +237,11 @@ on_toggle_source_clicked_cb (GbpGladeFrameAddin *self,
     }
   else
     {
+      GtkWidget *stack = gtk_widget_get_parent (GTK_WIDGET (other));
+
+      if (GTK_IS_STACK (stack))
+        gtk_stack_set_visible_child (GTK_STACK (stack), GTK_WIDGET (other));
+
       gtk_widget_grab_focus (GTK_WIDGET (other));
     }
 }