Make MetaDisplay a real GObject

We need this to be able to add signals, among other things.

http://bugzilla.gnome.org/show_bug.cgi?id=563047

src/core/display-private.h

@@ -74,6 +74,8 @@ typedef void (* MetaWindowPingFunc) (MetaDisplay *display,
 
 struct _MetaDisplay
 {
+  GObject parent_instance;
+  
   char *name;
   Display *xdisplay;
 
@@ -298,6 +300,11 @@ struct _MetaDisplay
 #endif
 };
 
+struct _MetaDisplayClass
+{
+  GObjectClass parent_class;
+};
+
 /* Xserver time can wraparound, thus comparing two timestamps needs to take
  * this into account.  Here's a little macro to help out.  If no wraparound
  * has occurred, this is equivalent to

src/core/display.c

@@ -127,6 +127,8 @@ typedef struct
   Window xwindow;
 } MetaAutoRaiseData;
 
+G_DEFINE_TYPE(MetaDisplay, meta_display, G_TYPE_OBJECT);
+
 /**
  * The display we're managing.  This is a singleton object.  (Historically,
  * this was a list of displays, but there was never any way to add more
@@ -163,6 +165,12 @@ static void    sanity_check_timestamps   (MetaDisplay *display,
 
 MetaGroup*     get_focussed_group (MetaDisplay *display);
 
+static void
+meta_display_class_init (MetaDisplayClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+}
+
 /**
  * Destructor for MetaPingData structs. Will destroy the
  * event source for the struct as well.
@@ -298,6 +306,13 @@ disable_compositor (MetaDisplay *display)
   display->compositor = NULL;
 }
 
+static void
+meta_display_init (MetaDisplay *disp)
+{
+  /* Some stuff could go in here that's currently in _open,
+   * but it doesn't really matter. */
+}
+
 /**
  * Opens a new display, sets it up, initialises all the X extensions
  * we will need, and adds it to the list of displays.
@@ -340,7 +355,7 @@ meta_display_open (void)
     XSynchronize (xdisplay, True);
   
   g_assert (the_display == NULL);
-  the_display = g_new (MetaDisplay, 1);
+  the_display = g_object_new (META_TYPE_DISPLAY, NULL);
 
   the_display->closing = 0;
   

src/include/display.h

@@ -22,11 +22,22 @@
 #ifndef META_DISPLAY_H
 #define META_DISPLAY_H
 
-#include <glib.h>
+#include <glib-object.h>
 #include <X11/Xlib.h>
 
 #include "types.h"
 
+typedef struct _MetaDisplayClass MetaDisplayClass;
+
+#define META_TYPE_DISPLAY              (meta_display_get_type ())
+#define META_DISPLAY(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), META_TYPE_DISPLAY, MetaDisplay))
+#define META_DISPLAY_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), META_TYPE_DISPLAY, MetaDisplayClass))
+#define META_IS_DISPLAY(object)        (G_TYPE_CHECK_INSTANCE_TYPE ((object), META_TYPE_DISPLAY))
+#define META_IS_DISPLAY_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), META_TYPE_DISPLAY))
+#define META_DISPLAY_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), META_TYPE_DISPLAY, MetaDisplayClass))
+
+GType meta_display_get_type (void) G_GNUC_CONST;
+
 #define meta_XFree(p) do { if ((p)) XFree ((p)); } while (0)
 
 typedef enum