Initial revision

git-svn-id: svn://localhost/trunk/ardour2@4 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/glibmm2/glibmm/signalproxy_connectionnode.cc

@@ -0,0 +1,94 @@
+// -*- c++ -*-
+
+/* $Id$ */
+
+/* signalproxy_connectionnode.cc
+ *
+ * Copyright (C) 2002 The gtkmm Development Team
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <glibmm/signalproxy_connectionnode.h>
+#include <glibmm/object.h>
+
+
+namespace Glib
+{
+
+SignalProxyConnectionNode::SignalProxyConnectionNode(const sigc::slot_base& slot, GObject* gobject)
+:
+  connection_id_ (0),
+  slot_          (slot),
+  object_        (gobject)
+{
+  //The cleanup callback will be called when the connection is disconnected.
+  slot_.set_parent(this, &SignalProxyConnectionNode::notify /* cleanup callback */);
+}
+
+// notify is a message coming up from the slot to be passed back to Gtk+
+// disconnect is a message coming up from the Gtk+ to be passed down to SigC++
+//static
+void* SignalProxyConnectionNode::notify(void* data)
+{
+  // notification from libsigc++.
+  SignalProxyConnectionNode* conn = static_cast<SignalProxyConnectionNode*>(data);
+
+  // If there is no object, this call was triggered from destroy_notify_handler(),
+  // because we set conn->object to 0 there:
+  if(conn && conn->object_)
+  {
+    GObject* o = conn->object_;
+    conn->object_ = 0;
+  
+    if(g_signal_handler_is_connected(o, conn->connection_id_)) //We check first, because during destruction, GTK+ sometimes seems to disconnect them for us, before we expect it to.  See bug #87912
+    {
+      // Disconnecting triggers execution of destroy_notify_handler(), eiter immediately or later:
+      //   When the signal handler is currently running. (for instance, if the callback disconnects its own connection)
+      //   In that case, destroy_notify_handler() will be called after this whole function has returned.
+      // Anyway. destroy_notify_handler() will always be called, so we leave that to do the deletion.
+
+      
+      //Forget the connection:
+      gulong connection_id = conn->connection_id_;
+      conn->connection_id_ = 0;
+      
+      g_signal_handler_disconnect(o, connection_id);
+    }
+  }
+
+  return 0; // apparently unused in libsigc++
+}
+
+//static
+void SignalProxyConnectionNode::destroy_notify_handler(gpointer data, GClosure*)
+{
+  //glib calls this when it has finished with a glib signal connection,
+  //either when the emitting object dies, or when the connection has been disconnected.
+  
+  // notification from gtk+.
+  SignalProxyConnectionNode* conn = static_cast<SignalProxyConnectionNode*>(data);
+
+  if(conn)
+  {
+    // the object has already lost track of this object.
+    conn->object_ = 0;
+
+    delete conn; // if there are connection objects referring to slot_ they are notified during destruction of slot_
+  }
+}
+
+} /* namespace Glib */
+