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_VIEWUPDATE_HXX 25 #define INCLUDED_SLIDESHOW_VIEWUPDATE_HXX 26 27 #include "disposable.hxx" 28 #include "view.hxx" 29 #include <boost/shared_ptr.hpp> 30 31 /* Definition of ViewUpdate interface */ 32 33 namespace slideshow 34 { 35 namespace internal 36 { 37 /** Interface for something that can perform view updates. 38 39 Use this interface for objects that perform view updates 40 from time to time, e.g. slide content. Availability of 41 updates can be queried, and subsequently performed. 42 */ 43 class ViewUpdate : public Disposable 44 { 45 public: 46 /** Perform the update action on all views 47 48 @return true, if the update was performed 49 successfully, false otherwise. 50 */ 51 virtual bool update() = 0; 52 53 /** Perform the update action on given view only 54 55 @return true, if the update was performed 56 successfully, false otherwise. 57 */ 58 virtual bool update( ViewSharedPtr const& rView ) = 0; 59 60 /** Query whether updates are pending 61 62 @return true, if updates are pending. Calling update() 63 subsequently will perform the pending update then. 64 */ 65 virtual bool needsUpdate() const = 0; 66 }; 67 68 typedef ::boost::shared_ptr< ViewUpdate > ViewUpdateSharedPtr; 69 } 70 } 71 72 #endif /* INCLUDED_SLIDESHOW_VIEWUPDATE_HXX */ 73