From b1953ec4e3a93e63b323e69ac0a1a2d76350094e Mon Sep 17 00:00:00 2001
From: codereader <greebo@angua.at>
Date: Sat, 1 Jul 2017 18:20:39 +0200
Subject: [PATCH] TraversableNodeSet migrated to use UndoSystem signals

---
 libs/scene/TraversableNodeSet.cpp | 15 +++++++--------
 libs/scene/TraversableNodeSet.h   | 14 +++++++++-----
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/libs/scene/TraversableNodeSet.cpp b/libs/scene/TraversableNodeSet.cpp
index 7f29785e68..80fa78da0b 100644
--- a/libs/scene/TraversableNodeSet.cpp
+++ b/libs/scene/TraversableNodeSet.cpp
@@ -263,20 +263,19 @@ void TraversableNodeSet::importState(const IUndoMementoPtr& state)
 	if (!_undoInsertBuffer.empty())
 	{
 		// Register to get notified when the undo operation is complete
-		GlobalUndoSystem().addObserver(this);
+		_undoHandler = GlobalUndoSystem().signal_postUndo().connect(
+			sigc::mem_fun(this, &TraversableNodeSet::onUndoRedoOperationFinished));
+		_redoHandler = GlobalUndoSystem().signal_postRedo().connect(
+			sigc::mem_fun(this, &TraversableNodeSet::onUndoRedoOperationFinished));
 	}
 }
 
-void TraversableNodeSet::postUndo()
+void TraversableNodeSet::onUndoRedoOperationFinished()
 {
-	processInsertBuffer();
-	GlobalUndoSystem().removeObserver(this);
-}
+	_undoHandler.disconnect();
+	_redoHandler.disconnect();
 
-void TraversableNodeSet::postRedo()
-{
 	processInsertBuffer();
-	GlobalUndoSystem().removeObserver(this);
 }
 
 void TraversableNodeSet::processInsertBuffer()
diff --git a/libs/scene/TraversableNodeSet.h b/libs/scene/TraversableNodeSet.h
index 40b2f2a04f..f76c9a000c 100644
--- a/libs/scene/TraversableNodeSet.h
+++ b/libs/scene/TraversableNodeSet.h
@@ -4,6 +4,8 @@
 #include "iundo.h"
 #include <list>
 #include <boost/noncopyable.hpp>
+#include <sigc++/connection.h>
+#include <sigc++/trackable.h>
 
 class IMapFileChangeTracker;
 
@@ -24,7 +26,7 @@ class Node;
 class TraversableNodeSet :
 	public IUndoable,
 	public boost::noncopyable,
-	public UndoSystem::Observer
+	public sigc::trackable
 {
 public:
 	typedef std::list<INodePtr> NodeList;
@@ -40,6 +42,9 @@ class TraversableNodeSet :
 	// A list collecting nodes for insertion in postUndo/postRedo
 	NodeList _undoInsertBuffer;
 
+	sigc::connection _undoHandler;
+	sigc::connection _redoHandler;
+
 public:
 	// Default constructor, creates an empty set
 	TraversableNodeSet(Node& owner);
@@ -91,13 +96,12 @@ class TraversableNodeSet :
 	IUndoMementoPtr exportState() const;
 	void importState(const IUndoMementoPtr& state);
 
-	// UndoSystem::Observer implementation
-	void postUndo();
-	void postRedo();
-
 	void setRenderSystem(const RenderSystemPtr& renderSystem);
 
 private:
+	// UndoSystem event handler
+	void onUndoRedoOperationFinished();
+
 	// Sends the current state to the undosystem
 	void undoSave();