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#ifndef INCLUDED_PDFI_TREEVISITORFACTORY_HXX
#define INCLUDED_PDFI_TREEVISITORFACTORY_HXX

#include "pdfihelper.hxx"
#include <boost/shared_ptr.hpp>

namespace pdfi
{
    struct ElementTreeVisitor;
    struct EmitContext;
    class PDFIProcessor;
    class StyleContainer;

    /** Tree manipulation factory

        Creates visitor objects performing various operations on the
        pdf parse tree
     */
    struct TreeVisitorFactory
    {
        virtual ~TreeVisitorFactory() {}

        /// Create visitor that combines tree nodes
        virtual boost::shared_ptr<ElementTreeVisitor> createOptimizingVisitor(PDFIProcessor&) const = 0;
        /// Create visitor that prepares style info
        virtual boost::shared_ptr<ElementTreeVisitor> createStyleCollectingVisitor(
            StyleContainer&, PDFIProcessor&) const = 0;
        /// Create visitor that emits tree to an output target
        virtual boost::shared_ptr<ElementTreeVisitor> createEmittingVisitor(EmitContext&, PDFIProcessor&) const = 0;
    };

    typedef boost::shared_ptr<TreeVisitorFactory> TreeVisitorFactorySharedPtr;

    TreeVisitorFactorySharedPtr createWriterTreeVisitorFactory();
    TreeVisitorFactorySharedPtr createImpressTreeVisitorFactory();
    TreeVisitorFactorySharedPtr createDrawTreeVisitorFactory();
}

#endif