Abstract base class defining the interface for TIFF composite visitors (Visitor pattern) More...

#include <tiffvisitor_int.hpp>

Inheritance diagram for Exiv2::Internal::TiffVisitor:

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Public Types
enum	GoEvent { geTraverse = 0 , geKnownMakernote = 1 }
	Events for the stop/go flag. See setGo(). More...

Public Member Functions
Creators
virtual	~TiffVisitor ()=default
	Virtual destructor.

Manipulators
void	setGo (GoEvent event, bool go)
	Set the stop/go flag: true for go, false for stop.

virtual void	visitEntry (TiffEntry *object)=0
	Operation to perform for a TIFF entry.

virtual void	visitDataEntry (TiffDataEntry *object)=0
	Operation to perform for a TIFF data entry.

virtual void	visitImageEntry (TiffImageEntry *object)=0
	Operation to perform for a TIFF image entry.

virtual void	visitSizeEntry (TiffSizeEntry *object)=0
	Operation to perform for a TIFF size entry.

virtual void	visitDirectory (TiffDirectory *object)=0
	Operation to perform for a TIFF directory.

virtual void	visitDirectoryNext (TiffDirectory *object)
	Operation to perform for a TIFF directory, after all components and before the next entry is processed.

virtual void	visitDirectoryEnd (TiffDirectory *object)
	Operation to perform for a TIFF directory, at the end of the processing.

virtual void	visitSubIfd (TiffSubIfd *object)=0
	Operation to perform for a TIFF sub-IFD.

virtual void	visitMnEntry (TiffMnEntry *object)=0
	Operation to perform for the makernote component.

virtual void	visitIfdMakernote (TiffIfdMakernote *object)=0
	Operation to perform for an IFD makernote.

virtual void	visitIfdMakernoteEnd (TiffIfdMakernote *object)
	Operation to perform after processing an IFD makernote.

virtual void	visitBinaryArray (TiffBinaryArray *object)=0
	Operation to perform for a binary array.

virtual void	visitBinaryArrayEnd (TiffBinaryArray *object)
	Operation to perform for a TIFF binary array, at the end of the processing.

virtual void	visitBinaryElement (TiffBinaryElement *object)=0
	Operation to perform for an element of a binary array.

Accessors
bool	go (GoEvent event) const
	Check if stop flag for event is clear, return true if it's clear.

Detailed Description

Abstract base class defining the interface for TIFF composite visitors (Visitor pattern)

A concrete visitor class is used as shown in the example below. Accept() will invoke the member function corresponding to the concrete type of each component in the composite.

void visitorExample(Exiv2::TiffComponent* tiffComponent, Exiv2::TiffVisitor& visitor)
{
    tiffComponent->accept(visitor);
}

Member Enumeration Documentation

◆ GoEvent

enum Exiv2::Internal::TiffVisitor::GoEvent

Events for the stop/go flag. See setGo().

Enumerator
geTraverse	Signal to control traversing of the composite tree.
geKnownMakernote	Signal used by TiffReader to signal an unknown makernote.

Member Function Documentation

◆ setGo()

void Exiv2::Internal::TiffVisitor::setGo	(	GoEvent	event,
		bool	go
	)

Set the stop/go flag: true for go, false for stop.

This mechanism is used by visitors and components to signal special events. Specifically, TiffFinder sets the geTraverse flag as soon as it finds the correct component to signal to components that the search should be aborted. TiffReader uses geKnownMakernote to signal problems reading a makernote to the TiffMnEntry component. There is an array of flags, one for each defined event, so different signals can be used independent of each other.

References go().

Referenced by Exiv2::Internal::TiffFinder::findObject(), Exiv2::Internal::TiffFinder::init(), Exiv2::Internal::TiffEncoder::setDirty(), and Exiv2::Internal::TiffReader::visitIfdMakernote().