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21 
22 
23 
24 #ifndef INCLUDED_PDFI_TREEVISITING_HXX
25 #define INCLUDED_PDFI_TREEVISITING_HXX
26 
27 #include <sal/config.h>
28 #include <list>
29 
30 
31 namespace pdfi
32 {
33     class  PDFIProcessor;
34     class  StyleContainer;
35     struct HyperlinkElement;
36     struct TextElement;
37     struct ParagraphElement;
38     struct FrameElement;
39     struct PolyPolyElement;
40     struct ImageElement;
41     struct PageElement;
42     struct DocumentElement;
43     struct EmitContext;
44     struct Element;
45 
46     /** To be visited by all tree element types
47 
48         Visitor interface from the "visitor pattern". Implementor gets
49         called with actual tree node instances.
50      */
51     struct ElementTreeVisitor
52     {
53         virtual void visit( HyperlinkElement&, const std::list< Element* >::const_iterator& ) = 0;
54         virtual void visit( TextElement&, const std::list< Element* >::const_iterator&  ) = 0;
55         virtual void visit( ParagraphElement&, const std::list< Element* >::const_iterator&  ) = 0;
56         virtual void visit( FrameElement&, const std::list< Element* >::const_iterator&  ) = 0;
57         virtual void visit( PolyPolyElement&, const std::list< Element* >::const_iterator&  ) = 0;
58         virtual void visit( ImageElement&, const std::list< Element* >::const_iterator&  ) = 0;
59         virtual void visit( PageElement&, const std::list< Element* >::const_iterator&  ) = 0;
60         virtual void visit( DocumentElement&, const std::list< Element* >::const_iterator&  ) = 0;
61     };
62     typedef boost::shared_ptr<ElementTreeVisitor> ElementTreeVisitorSharedPtr;
63 
64     /** Visitee interface
65 
66         To be implemented by every tree node that needs to be
67         visitable.
68      */
69     struct ElementTreeVisitable
70     {
71         virtual void visitedBy( ElementTreeVisitor&, const std::list< Element* >::const_iterator& rParentIt ) = 0;
72     };
73     typedef boost::shared_ptr<ElementTreeVisitable> ElementTreeVisitableSharedPtr;
74 }
75 
76 #endif
77