1*b1cdbd2cSJim Jagielski /************************************************************** 2*b1cdbd2cSJim Jagielski * 3*b1cdbd2cSJim Jagielski * Licensed to the Apache Software Foundation (ASF) under one 4*b1cdbd2cSJim Jagielski * or more contributor license agreements. See the NOTICE file 5*b1cdbd2cSJim Jagielski * distributed with this work for additional information 6*b1cdbd2cSJim Jagielski * regarding copyright ownership. The ASF licenses this file 7*b1cdbd2cSJim Jagielski * to you under the Apache License, Version 2.0 (the 8*b1cdbd2cSJim Jagielski * "License"); you may not use this file except in compliance 9*b1cdbd2cSJim Jagielski * with the License. You may obtain a copy of the License at 10*b1cdbd2cSJim Jagielski * 11*b1cdbd2cSJim Jagielski * http://www.apache.org/licenses/LICENSE-2.0 12*b1cdbd2cSJim Jagielski * 13*b1cdbd2cSJim Jagielski * Unless required by applicable law or agreed to in writing, 14*b1cdbd2cSJim Jagielski * software distributed under the License is distributed on an 15*b1cdbd2cSJim Jagielski * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*b1cdbd2cSJim Jagielski * KIND, either express or implied. See the License for the 17*b1cdbd2cSJim Jagielski * specific language governing permissions and limitations 18*b1cdbd2cSJim Jagielski * under the License. 19*b1cdbd2cSJim Jagielski * 20*b1cdbd2cSJim Jagielski *************************************************************/ 21*b1cdbd2cSJim Jagielski 22*b1cdbd2cSJim Jagielski 23*b1cdbd2cSJim Jagielski 24*b1cdbd2cSJim Jagielski #ifndef INCLUDED_SLIDESHOW_STATE_HXX 25*b1cdbd2cSJim Jagielski #define INCLUDED_SLIDESHOW_STATE_HXX 26*b1cdbd2cSJim Jagielski 27*b1cdbd2cSJim Jagielski #include <sal/types.h> 28*b1cdbd2cSJim Jagielski #include <boost/shared_ptr.hpp> 29*b1cdbd2cSJim Jagielski 30*b1cdbd2cSJim Jagielski 31*b1cdbd2cSJim Jagielski /* Definition of State interface */ 32*b1cdbd2cSJim Jagielski 33*b1cdbd2cSJim Jagielski namespace slideshow 34*b1cdbd2cSJim Jagielski { 35*b1cdbd2cSJim Jagielski namespace internal 36*b1cdbd2cSJim Jagielski { 37*b1cdbd2cSJim Jagielski 38*b1cdbd2cSJim Jagielski /** This interface represents a stateful object. 39*b1cdbd2cSJim Jagielski 40*b1cdbd2cSJim Jagielski The state ID returned by the getStateId() method 41*b1cdbd2cSJim Jagielski abstractly encodes the object's state. When this ID 42*b1cdbd2cSJim Jagielski changes, clients can assume that the object's state has 43*b1cdbd2cSJim Jagielski changed. 44*b1cdbd2cSJim Jagielski */ 45*b1cdbd2cSJim Jagielski class State 46*b1cdbd2cSJim Jagielski { 47*b1cdbd2cSJim Jagielski public: ~State()48*b1cdbd2cSJim Jagielski virtual ~State() {} 49*b1cdbd2cSJim Jagielski 50*b1cdbd2cSJim Jagielski /// Abstract, numerically encoded state ID 51*b1cdbd2cSJim Jagielski typedef ::std::size_t StateId; 52*b1cdbd2cSJim Jagielski 53*b1cdbd2cSJim Jagielski /** This method returns a numerical state identifier. 54*b1cdbd2cSJim Jagielski 55*b1cdbd2cSJim Jagielski The state ID returned by this method abstractly 56*b1cdbd2cSJim Jagielski encodes the object's state. When this ID changes, 57*b1cdbd2cSJim Jagielski clients can assume that the object's state has 58*b1cdbd2cSJim Jagielski changed. 59*b1cdbd2cSJim Jagielski 60*b1cdbd2cSJim Jagielski @return an abstract, numerical state ID. 61*b1cdbd2cSJim Jagielski */ 62*b1cdbd2cSJim Jagielski virtual StateId getStateId() const = 0; 63*b1cdbd2cSJim Jagielski }; 64*b1cdbd2cSJim Jagielski 65*b1cdbd2cSJim Jagielski typedef ::boost::shared_ptr< State > StateSharedPtr; 66*b1cdbd2cSJim Jagielski } 67*b1cdbd2cSJim Jagielski } 68*b1cdbd2cSJim Jagielski 69*b1cdbd2cSJim Jagielski #endif /* INCLUDED_SLIDESHOW_STATE_HXX */ 70