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
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16*b1cdbd2cSJim Jagielski  * KIND, either express or implied.  See the License for the
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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_VIEWUPDATE_HXX
25*b1cdbd2cSJim Jagielski #define INCLUDED_SLIDESHOW_VIEWUPDATE_HXX
26*b1cdbd2cSJim Jagielski 
27*b1cdbd2cSJim Jagielski #include "disposable.hxx"
28*b1cdbd2cSJim Jagielski #include "view.hxx"
29*b1cdbd2cSJim Jagielski #include <boost/shared_ptr.hpp>
30*b1cdbd2cSJim Jagielski 
31*b1cdbd2cSJim Jagielski /* Definition of ViewUpdate interface */
32*b1cdbd2cSJim Jagielski 
33*b1cdbd2cSJim Jagielski namespace slideshow
34*b1cdbd2cSJim Jagielski {
35*b1cdbd2cSJim Jagielski     namespace internal
36*b1cdbd2cSJim Jagielski     {
37*b1cdbd2cSJim Jagielski         /** Interface for something that can perform view updates.
38*b1cdbd2cSJim Jagielski 
39*b1cdbd2cSJim Jagielski             Use this interface for objects that perform view updates
40*b1cdbd2cSJim Jagielski             from time to time, e.g. slide content. Availability of
41*b1cdbd2cSJim Jagielski             updates can be queried, and subsequently performed.
42*b1cdbd2cSJim Jagielski          */
43*b1cdbd2cSJim Jagielski         class ViewUpdate : public Disposable
44*b1cdbd2cSJim Jagielski         {
45*b1cdbd2cSJim Jagielski         public:
46*b1cdbd2cSJim Jagielski             /** Perform the update action on all views
47*b1cdbd2cSJim Jagielski 
48*b1cdbd2cSJim Jagielski                 @return true, if the update was performed
49*b1cdbd2cSJim Jagielski                 successfully, false otherwise.
50*b1cdbd2cSJim Jagielski              */
51*b1cdbd2cSJim Jagielski             virtual bool update() = 0;
52*b1cdbd2cSJim Jagielski 
53*b1cdbd2cSJim Jagielski             /** Perform the update action on given view only
54*b1cdbd2cSJim Jagielski 
55*b1cdbd2cSJim Jagielski                 @return true, if the update was performed
56*b1cdbd2cSJim Jagielski                 successfully, false otherwise.
57*b1cdbd2cSJim Jagielski              */
58*b1cdbd2cSJim Jagielski             virtual bool update( ViewSharedPtr const& rView ) = 0;
59*b1cdbd2cSJim Jagielski 
60*b1cdbd2cSJim Jagielski             /** Query whether updates are pending
61*b1cdbd2cSJim Jagielski 
62*b1cdbd2cSJim Jagielski                 @return true, if updates are pending. Calling update()
63*b1cdbd2cSJim Jagielski                 subsequently will perform the pending update then.
64*b1cdbd2cSJim Jagielski              */
65*b1cdbd2cSJim Jagielski             virtual bool needsUpdate() const = 0;
66*b1cdbd2cSJim Jagielski         };
67*b1cdbd2cSJim Jagielski 
68*b1cdbd2cSJim Jagielski         typedef ::boost::shared_ptr< ViewUpdate > ViewUpdateSharedPtr;
69*b1cdbd2cSJim Jagielski     }
70*b1cdbd2cSJim Jagielski }
71*b1cdbd2cSJim Jagielski 
72*b1cdbd2cSJim Jagielski #endif /* INCLUDED_SLIDESHOW_VIEWUPDATE_HXX */
73