[mutter/wip/tablet-protocol: 85/100] wayland: Add MetaWaylandSurface::destroy signal

[Carlos Garnacho <carlosg src gnome org>]

commit 5fb20bf0760c26b5c1adcef31fe3613617754f5c
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Oct 22 14:07:52 2015 +0200

    wayland: Add MetaWaylandSurface::destroy signal
    
    There's places where it would be convenient to add listeners to this,
    so add the signal. The signal is only emitted once during destruction,
    it is convenient for the places where we want notifications at a time
    the object is still alive, as opposed to weak refs which notify after
    the fact.

 src/wayland/meta-wayland-surface.c |   32 ++++++++++++++++++++++++++++++++
 src/wayland/meta-wayland-surface.h |    1 +
 2 files changed, 33 insertions(+), 0 deletions(-)
---
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index f9b3f3c..32f26eb 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -124,6 +124,13 @@ G_DEFINE_TYPE (MetaWaylandSurfaceRoleDND,
                meta_wayland_surface_role_dnd,
                META_TYPE_WAYLAND_SURFACE_ROLE);
 
+enum {
+  SURFACE_DESTROY,
+  N_SURFACE_SIGNALS
+};
+
+guint surface_signals[N_SURFACE_SIGNALS] = { 0 };
+
 static void
 meta_wayland_surface_role_assigned (MetaWaylandSurfaceRole *surface_role);
 
@@ -2414,6 +2421,20 @@ meta_wayland_surface_get_toplevel_window (MetaWaylandSurface *surface)
 }
 
 static void
+meta_wayland_surface_dispose (GObject *object)
+{
+  MetaWaylandSurface *surface = META_WAYLAND_SURFACE (object);
+
+  if (!surface->destroying)
+    {
+      g_signal_emit (object, surface_signals[SURFACE_DESTROY], 0);
+      surface->destroying = TRUE;
+    }
+
+  G_OBJECT_CLASS (meta_wayland_surface_parent_class)->dispose (object);
+}
+
+static void
 meta_wayland_surface_init (MetaWaylandSurface *surface)
 {
 }
@@ -2421,6 +2442,17 @@ meta_wayland_surface_init (MetaWaylandSurface *surface)
 static void
 meta_wayland_surface_class_init (MetaWaylandSurfaceClass *klass)
 {
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = meta_wayland_surface_dispose;
+
+  surface_signals[SURFACE_DESTROY] =
+    g_signal_new ("destroy",
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0, NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
 }
 
 static void
diff --git a/src/wayland/meta-wayland-surface.h b/src/wayland/meta-wayland-surface.h
index 7a5ec6d..cf24b4d 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -175,6 +175,7 @@ struct _MetaWaylandSurface
   MetaWaylandSerial acked_configure_serial;
   gboolean has_set_geometry;
   gboolean is_modal;
+  gboolean destroying;
 
   /* xdg_popup */
   struct {