pdfobjects::PdfOperator Class Reference

#include <pdfoperatorsbase.h>

Inheritance diagram for pdfobjects::PdfOperator:

Public Types
typedef std::deque < boost::shared_ptr< IProperty > >	Operands
typedef std::list < boost::shared_ptr < PdfOperator > >	PdfOperators
typedef iterator::DoubleListIterator < PdfOperator >	Iterator
typedef Iterator::ListItem	ListItem
typedef libs::Rectangle	BBox
Public Member Functions
virtual	~PdfOperator ()
virtual size_t	getParametersCount () const =0
virtual void	getParameters (Operands &container) const =0
virtual void	getStringRepresentation (std::string &str) const =0
virtual void	getOperatorName (std::string &first) const =0
virtual void	push_back (UNUSED_PARAM const boost::shared_ptr< PdfOperator > oper, UNUSED_PARAM boost::shared_ptr< PdfOperator > _prev=boost::shared_ptr< PdfOperator >())
virtual size_t	getChildrenCount () const
virtual void	getChildren (PdfOperators &opers) const
virtual boost::shared_ptr < PdfOperator >	clone ()=0
void	setContentStream (CContentStream &cs)
boost::shared_ptr< CContentStream >	getContentStream () const
void	setBBox (const BBox &rc)
BBox	getBBox () const
virtual void	init_operands (boost::shared_ptr< observer::IObserver< IProperty > >, boost::weak_ptr< CPdf >, IndiRef *)=0
Static Public Member Functions
template<typename ITER >
static ITER	getIterator (boost::shared_ptr< PdfOperator > op, bool forward)
template<typename ITER >
static ITER	getIterator (boost::shared_ptr< PdfOperator > op)
static Iterator	getIterator (boost::shared_ptr< PdfOperator > op)
Protected Member Functions
	PdfOperator ()
virtual void	insert_after (const boost::shared_ptr< PdfOperator >, boost::shared_ptr< PdfOperator >)
virtual void	remove (boost::shared_ptr< PdfOperator >)
Static Protected Member Functions
static void	putBehind (boost::shared_ptr< PdfOperator > behindWhich, boost::shared_ptr< PdfOperator > which)
Private Attributes
CContentStream *	_contentstream
BBox	_bbox
Friends
class	iterator::DoubleListIterator< PdfOperator >
class	CContentStream

Detailed Description

This class is the base class for COMPOSITE design pattern and also DECORATOR design pattern.

This is a special implementation, a hybrid between implementation of stl containers and GoF example.

Content stream consists of operators and their operands. Operators can be composites. Each operator alters graphical state in a predefined way. Operators have to be processed sequentially.

This is the building block of almost all visible objects on a page. Every operation on a text, graphics etc.. means adding/deleting/changing operators.

Operators themselves build a double linked list queue. We use iterators to iterate over them sequentially.

They also form a tree like structure and that is the reason why Composite design pattern is used here. Decorator and composite together allow a very easy way to change these operators. (e.g. changing font means wrapping the text operator to a composite, which includes also the font change operator.)

This approach allows us to represent operators in a human readable way (tree like structure) and to have the power of double linked list with iterators.

We can not simply represent these two queues in one. If we want to have all info only in interator queue, items can not be shared pointers because of the cyclic shared pointer problem (no item would get ever deallocated). If we want to have all the info in tree like queue, we would have to know the parents and it would not be easy to write an iterator. It would not be a clean straight forward solution. Another possibility is to have the queue outside (e.g. in content stream) but then we would not be able to simply create composites.

Another advantage of the composite design pattern is the single unified interface. In most cases we do not need to distinguish between a composite and a leaf.

Iterators are crucial when selecting operators.

Member Typedef Documentation

typedef libs::Rectangle pdfobjects::PdfOperator::BBox

typedef iterator::DoubleListIterator<PdfOperator> pdfobjects::PdfOperator::Iterator

typedef Iterator::ListItem pdfobjects::PdfOperator::ListItem

typedef std::deque<boost::shared_ptr<IProperty> > pdfobjects::PdfOperator::Operands

typedef std::list<boost::shared_ptr<PdfOperator> > pdfobjects::PdfOperator::PdfOperators

Constructor & Destructor Documentation

pdfobjects::PdfOperator::PdfOperator ( ) [inline, protected]

Constructor.

virtual pdfobjects::PdfOperator::~PdfOperator ( ) [inline, virtual]

Destructor.

Member Function Documentation

virtual boost::shared_ptr<PdfOperator> pdfobjects::PdfOperator::clone ( ) [pure virtual]

Clone this object.

Returns:: New clone.

Implemented in pdfobjects::SimpleGenericOperator, pdfobjects::UnknownCompositePdfOperator, pdfobjects::InlineImageCompositePdfOperator, and pdfobjects::CompositePdfOperator.

BBox pdfobjects::PdfOperator::getBBox ( ) const [inline]

Get bounding box of this operator.

Returns:: Bounding box.

References _bbox.

virtual void pdfobjects::PdfOperator::getChildren ( PdfOperators & opers ) const [inline, virtual]

Get childrens.

Parameters:

opers

Children container.

Reimplemented in pdfobjects::CompositePdfOperator.

virtual size_t pdfobjects::PdfOperator::getChildrenCount ( ) const [inline, virtual]

Get children count.

Returns:: Number of children.

Reimplemented in pdfobjects::CompositePdfOperator.

shared_ptr< CContentStream > pdfobjects::PdfOperator::getContentStream ( ) const

Get content stream.

Returns:: Content stream that this pdfoperator belongs to.

References _contentstream, and pdfobjects::CContentStream::getSmartPointer().

Referenced by pdfobjects::TextSimpleOperator::getCurrentFont().

static Iterator pdfobjects::PdfOperator::getIterator ( boost::shared_ptr< PdfOperator > op ) [inline, static]

Create simple iterator.

template<typename ITER >

static ITER pdfobjects::PdfOperator::getIterator ( boost::shared_ptr< PdfOperator > op ) [inline, static]

Get iterator.REMARK: We can't simply make getIterator a method, because we have to know the smart pointer behind the object. Member variable "this" is not sufficient.

Parameters:

	op	Operator from which we want the iterator.
	forward	Direction of traversing when looking for the first valid item.

Returns:: Iterator.

.

template<typename ITER >

static ITER pdfobjects::PdfOperator::getIterator	(	boost::shared_ptr< PdfOperator >	op,
		bool	forward
	)			`[inline, static]`

Get iterator.

REMARK: We can't simply make getIterator a method, because we have to know the smart pointer behind the object. Member variable "this" is not sufficient.

Parameters:

	op	Operator from which we want the iterator.
	forward	Direction of traversing when looking for the first valid item.

Returns:: Iterator.

Referenced by pdfobjects::CContentStream::CContentStream(), pdfobjects::CPageContents::convert(), pdfobjects::CContentStream::deleteOperator(), pdfobjects::CContentStream::insertOperator(), pdfobjects::CPageContents::parse(), gui::QSPdfOperatorIterator::QSPdfOperatorIterator(), pdfobjects::CContentStream::reparse(), and pdfobjects::CContentStream::replaceOperator().

virtual void pdfobjects::PdfOperator::getOperatorName ( std::string & first ) const [pure virtual]

Get the string operator name.

Parameters:

first

String that will hold operator name.

Implemented in pdfobjects::SimpleGenericOperator, pdfobjects::UnknownCompositePdfOperator, pdfobjects::InlineImageCompositePdfOperator, and pdfobjects::CompositePdfOperator.

Referenced by pdfobjects::isPdfOp().

virtual void pdfobjects::PdfOperator::getParameters ( Operands & container ) const [pure virtual]

Get the parameters used with this operator.

Parameters:

container

Will be used to store parameters.

Implemented in pdfobjects::SimpleGenericOperator, pdfobjects::InlineImageCompositePdfOperator, and pdfobjects::CompositePdfOperator.

virtual size_t pdfobjects::PdfOperator::getParametersCount ( ) const [pure virtual]

Return the number of parameters.

Returns:: Number of parameters.

Implemented in pdfobjects::SimpleGenericOperator, pdfobjects::InlineImageCompositePdfOperator, and pdfobjects::CompositePdfOperator.

virtual void pdfobjects::PdfOperator::getStringRepresentation ( std::string & str ) const [pure virtual]

Get the string representation of this operator.

Parameters:

str

String that will hold the representation of this operator.

Implemented in pdfobjects::SimpleGenericOperator, pdfobjects::UnknownCompositePdfOperator, pdfobjects::InlineImageCompositePdfOperator, and pdfobjects::CompositePdfOperator.

virtual void pdfobjects::PdfOperator::init_operands	(	boost::shared_ptr< observer::IObserver< IProperty > >	,
		boost::weak_ptr< CPdf >	,
		IndiRef *
	)			`[pure virtual]`

Init operands and store observer for later unregistering.

Implemented in pdfobjects::SimpleGenericOperator, and pdfobjects::CompositePdfOperator.

virtual void pdfobjects::PdfOperator::insert_after	(	const boost::shared_ptr< PdfOperator >	,
		boost::shared_ptr< PdfOperator >
	)			`[inline, protected, virtual]`

Insert an operator after an item.

Parameters:

	oper	Operator after which an oper will be inserted.
	newOper	Operator to be inserted.

Reimplemented in pdfobjects::CompositePdfOperator.

virtual void pdfobjects::PdfOperator::push_back	(	UNUSED_PARAM const boost::shared_ptr< PdfOperator >	oper,
		UNUSED_PARAM boost::shared_ptr< PdfOperator >	_prev = `boost::shared_ptr<PdfOperator> ()`
	)			`[inline, virtual]`

Add an operator to the end of composite. One problem is when the composite is empty, we have to specify prev variable because we can not get shared pointer from this.

Parameters:

	oper	Operator to be added.
	prev	Operator, after which we should place the added one in iterator list. If not specified, it is assumed that children are not empty and that the last item is not a composite.

static void pdfobjects::PdfOperator::putBehind	(	boost::shared_ptr< PdfOperator >	behindWhich,
		boost::shared_ptr< PdfOperator >	which
	)			`[static, protected]`

Put behind.

REMARK: We can't simply make putBehind a method, because we have to know the smart pointer behind the object. Member variable "this" is not sufficient.

Parameters:

	behindWhich	Behind which elemnt.
	which	Which element.

virtual void pdfobjects::PdfOperator::remove ( boost::shared_ptr< PdfOperator > ) [inline, protected, virtual]

Remove an operator from the composite interface.

REMARK: This will not remove it from the Iterator list.

Parameters:

op

to be erased.

Reimplemented in pdfobjects::CompositePdfOperator.

void pdfobjects::PdfOperator::setBBox ( const BBox & rc ) [inline]

Set bounding box.

Parameters:

rc

Bounding box.

References _bbox.

void pdfobjects::PdfOperator::setContentStream ( CContentStream & cs ) [inline]

Set content stream.

Every pdf operator needs to know into which content stream it belongs. This is due to the fact, that some functions just return container of pdfoperators, and if we want to work with them, we have to know the contentstream.

We can find out the CStream but there is no mapping between CStream and content stream.

Parameters:

cs

Content stream.

References _contentstream.