[gtk+] Implement GInitable in GdkX11DisplayManager

[Matthias Clasen <matthiasc src gnome org>]

commit bfcf9e471dc3c45644287eaebfbcae1b03bfd8b1
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Mar 23 00:37:53 2013 -0400

    Implement GInitable in GdkX11DisplayManager
    
    Add GInitable implementation and fail the initialisation if it is not
    possible to connect to the display server.

 gdk/x11/gdkdisplaymanager-x11.c |   37 +++++++++++++++++++++++++++++++++++--
 1 files changed, 35 insertions(+), 2 deletions(-)
---
diff --git a/gdk/x11/gdkdisplaymanager-x11.c b/gdk/x11/gdkdisplaymanager-x11.c
index 544036f..44bd177 100644
--- a/gdk/x11/gdkdisplaymanager-x11.c
+++ b/gdk/x11/gdkdisplaymanager-x11.c
@@ -34,6 +34,8 @@ struct _GdkX11DisplayManager
 
   GdkDisplay *default_display;
   GSList *displays;
+
+  gboolean init_failed;
 };
 
 struct _GdkX11DisplayManagerClass
@@ -41,7 +43,37 @@ struct _GdkX11DisplayManagerClass
   GdkDisplayManagerClass parent_class;
 };
 
-G_DEFINE_TYPE (GdkX11DisplayManager, gdk_x11_display_manager, GDK_TYPE_DISPLAY_MANAGER)
+static void g_initable_iface_init (GInitableIface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (GdkX11DisplayManager, gdk_x11_display_manager, GDK_TYPE_DISPLAY_MANAGER,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE, g_initable_iface_init))
+
+static gboolean
+gdk_x11_display_manager_initable_init (GInitable     *initable,
+                                       GCancellable  *cancellable,
+                                       GError       **error)
+{
+  Display *display;
+
+  /* check that a connection to the default display is possible */
+  display = XOpenDisplay (gdk_get_display_arg_name ());
+  if (!display)
+    {
+      GDK_X11_DISPLAY_MANAGER (initable)->init_failed = TRUE;
+      return FALSE;
+    }
+
+  XCloseDisplay (display);
+
+  return TRUE;
+}
+
+void
+g_initable_iface_init (GInitableIface *iface)
+{
+  iface->init = gdk_x11_display_manager_initable_init;
+}
+
 
 static GdkDisplay *
 gdk_x11_display_manager_open_display (GdkDisplayManager *manager,
@@ -93,7 +125,8 @@ gdk_x11_display_manager_init (GdkX11DisplayManager *manager)
 static void
 gdk_x11_display_manager_finalize (GObject *object)
 {
-  g_error ("A GdkX11DisplayManager object was finalized. This should not happen");
+  if (GDK_X11_DISPLAY_MANAGER (object)->init_failed == FALSE)
+    g_error ("A GdkX11DisplayManager object was finalized. This should not happen");
   G_OBJECT_CLASS (gdk_x11_display_manager_parent_class)->finalize (object);
 }