text: /*************************************************************************/
  /*  undo_redo.h                                                          */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                    http://www.godotengine.org                         */
  /*************************************************************************/
  /* Copyright (c) 2007-2015 Juan Linietsky, Ariel Manzur.                 */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  #ifndef UNDO_REDO_H
  #define UNDO_REDO_H
  
  #include "object.h"
  #include "resource.h"
  
  
  
  
  class UndoRedo : public Object {
  
  	OBJ_TYPE(UndoRedo,Object);
  public:
  
  	typedef void (*CommitNotifyCallback)(void *p_ud,const String& p_name);
  
  private:
  	struct Operation {
  
  		enum Type {
  			TYPE_METHOD,
  			TYPE_PROPERTY,
  			TYPE_REFERENCE
  		};
  
  		Type type;
  		Ref<Resource> resref;
  		ObjectID object;
  		String name;
  		Variant args[VARIANT_ARG_MAX];
  
  	};
  
  
  	struct Action {
  		String name;
  		List<Operation> do_ops;
  		List<Operation> undo_ops;
  	};
  
  	Vector<Action> actions;
  	int current_action;
  	int action_level;
  	int max_steps;
  	bool merging;
  	uint64_t version;
  
  	void _pop_history_tail();
  	void _process_operation_list(List<Operation>::Element *E);
  	void _discard_redo();
  
  
  	CommitNotifyCallback callback;
  	void* callback_ud;
  
  public:
  
  	void create_action(const String& p_name="",bool p_mergeable=false);
  
  	void add_do_method(Object *p_object,const String& p_method,VARIANT_ARG_LIST);
  	void add_undo_method(Object *p_object,const String& p_method,VARIANT_ARG_LIST);
  	void add_do_property(Object *p_object,const String& p_property,const Variant& p_value);
  	void add_undo_property(Object *p_object,const String& p_property,const Variant& p_value);
  	void add_do_reference(Object *p_object);
  	void add_undo_reference(Object *p_object);
  
  	void commit_action();
  
  	void redo();
  	void undo();
  	String get_current_action_name() const;
  	void clear_history();
  
  	void set_max_steps(int p_max_steps);
  	int get_max_steps() const;
  
  	uint64_t get_version() const;
  
  	void set_commit_notify_callback(CommitNotifyCallback p_callback,void* p_ud);
  
  	UndoRedo();
  	~UndoRedo();
  };
  
  #endif // UNDO_REDO_H
  