[mutter/wip/tablet-protocol-v3: 2/18] wayland: Add MetaWaylandSurface::destroy signal

[Carlos Garnacho <carlosg src gnome org>]

commit ebd44db48c59f410ef90eff50acfbd0c7335ae53
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 4726e90..7d7c0e0 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);
 
@@ -2407,6 +2414,20 @@ 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)
 {
 }
@@ -2414,6 +2435,17 @@ 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 94ba100..03af951 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -173,6 +173,7 @@ struct _MetaWaylandSurface
   MetaWaylandSerial acked_configure_serial;
   gboolean has_set_geometry;
   gboolean is_modal;
+  gboolean destroying;
 
   /* xdg_popup */
   struct {