1 files changed, 96 insertions, 0 deletions
diff --git a/libs/pbd/pbd/undo.h b/libs/pbd/pbd/undo.h
new file mode 100644
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+++ b/libs/pbd/pbd/undo.h
@@ -0,0 +1,96 @@
+/* 
+   Copyright (C) 2002 Brett Viren & Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+    $Id$
+*/
+
+#ifndef __lib_pbd_undo_h__
+#define __lib_pbd_undo_h__
+
+#include <string>
+#include <list>
+#include <sigc++/slot.h>
+#include <sys/time.h>
+
+using std::string;
+using std::list;
+
+typedef sigc::slot<void> UndoAction;
+
+class UndoCommand 
+{
+  public:
+	UndoCommand ();
+	UndoCommand (const UndoCommand&);
+	UndoCommand& operator= (const UndoCommand&);
+
+	void clear ();
+
+	void add_undo (const UndoAction&);
+	void add_redo (const UndoAction&);
+	void add_redo_no_execute (const UndoAction&);
+
+	void undo();
+	void redo();
+	
+	void set_name (const string& str) {
+		_name = str;
+	}
+	const string& name() const { return _name; }
+
+	void set_timestamp (struct timeval &t) {
+		_timestamp = t;
+	}
+
+	const struct timeval& timestamp() const {
+		return _timestamp;
+	}
+
+  private:
+	list<UndoAction> redo_actions;
+	list<UndoAction> undo_actions;
+	struct timeval   _timestamp;
+	string           _name;
+};
+
+class UndoHistory
+{
+  public:
+	UndoHistory() {}
+	~UndoHistory() {}
+	
+	void add (UndoCommand uc);
+	void undo (unsigned int n);
+	void redo (unsigned int n);
+	
+	unsigned long undo_depth() const { return UndoList.size(); }
+	unsigned long redo_depth() const { return RedoList.size(); }
+	
+	string next_undo() const { return (UndoList.empty() ? string("") : UndoList.back().name()); }
+	string next_redo() const { return (RedoList.empty() ? string("") : RedoList.back().name()); }
+
+	void clear ();
+	void clear_undo ();
+	void clear_redo ();
+
+  private:
+	list<UndoCommand> UndoList;
+	list<UndoCommand> RedoList;
+};
+
+
+#endif /* __lib_pbd_undo_h__ */