[gnome-builder] gui: hide close-button when in fullscreen

[Christian Hergert <chergert src gnome org>]

commit 6bdc0850a5080ced20c69b9fcd549889d5529002
Author: Christian Hergert <chergert redhat com>
Date:   Thu Sep 26 16:20:35 2019 -0700

    gui: hide close-button when in fullscreen

 src/libide/gui/ide-workspace.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/libide/gui/ide-workspace.c b/src/libide/gui/ide-workspace.c
index 39959dd96..8140a87bc 100644
--- a/src/libide/gui/ide-workspace.c
+++ b/src/libide/gui/ide-workspace.c
@@ -428,11 +428,15 @@ ide_workspace_real_set_fullscreen (DzlApplicationWindow *window,
 {
   IdeWorkspace *self = (IdeWorkspace *)window;
   IdeWorkspacePrivate *priv = ide_workspace_get_instance_private (self);
+  GtkWidget *titlebar;
 
   g_assert (IDE_IS_WORKSPACE (self));
 
   DZL_APPLICATION_WINDOW_CLASS (ide_workspace_parent_class)->set_fullscreen (window, fullscreen);
 
+  titlebar = dzl_application_window_get_titlebar (window);
+  gtk_header_bar_set_show_close_button (GTK_HEADER_BAR (titlebar), !fullscreen);
+
   gtk_container_foreach (GTK_CONTAINER (priv->surfaces),
                          ide_workspace_set_surface_fullscreen_cb,
                          GUINT_TO_POINTER (fullscreen));