text: // Copyright 2014 Goodow.com. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  // http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  //
  //  GDSUndoRedoStateChangedEvent.h
  //  GDStore
  //
  //  Created by Larry Tin.
  //
  
  #import <Foundation/Foundation.h>
  
  /**
   * An event indicating that canUndo or canRedo changed.
   */
  @protocol GDSUndoRedoStateChangedEvent
  
  /* True if you can currently redo, false otherwise. */
  - (BOOL)canRedo;
  
  /* True if you can currently undo, false otherwise. */
  - (BOOL)canUndo;
  
  @end