1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 24 #ifndef INCLUDED_SLIDESHOW_STATE_HXX 25 #define INCLUDED_SLIDESHOW_STATE_HXX 26 27 #include <sal/types.h> 28 #include <boost/shared_ptr.hpp> 29 30 31 /* Definition of State interface */ 32 33 namespace slideshow 34 { 35 namespace internal 36 { 37 38 /** This interface represents a stateful object. 39 40 The state ID returned by the getStateId() method 41 abstractly encodes the object's state. When this ID 42 changes, clients can assume that the object's state has 43 changed. 44 */ 45 class State 46 { 47 public: ~State()48 virtual ~State() {} 49 50 /// Abstract, numerically encoded state ID 51 typedef ::std::size_t StateId; 52 53 /** This method returns a numerical state identifier. 54 55 The state ID returned by this method abstractly 56 encodes the object's state. When this ID changes, 57 clients can assume that the object's state has 58 changed. 59 60 @return an abstract, numerical state ID. 61 */ 62 virtual StateId getStateId() const = 0; 63 }; 64 65 typedef ::boost::shared_ptr< State > StateSharedPtr; 66 } 67 } 68 69 #endif /* INCLUDED_SLIDESHOW_STATE_HXX */ 70