xref: /trunk/main/slideshow/source/inc/state.hxx (revision aaef562f)
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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