iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener Class Reference

An event listener which filters events on the fly before passing them on to the delegate. More...

Inheritance diagram for iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener:

Public Member Functions
	FilteredEventListener ()
	Constructs a FilteredEventListener empty instance. More...
	FilteredEventListener (IEventListener delegate_, params IEventFilter[] filterSet)
	Constructs a FilteredEventListener instance with one delegate. More...
virtual T	AttachEventListener< T > (T delegate_, params IEventFilter[] filterSet)
	Attaches another IEventListener delegate with its filters. More...
virtual void	EventOccurred (IEventData data, EventType type)
	Called when some event occurs during parsing a content stream. More...
virtual ICollection< EventType >	GetSupportedEvents ()
	Provides the set of event types this listener supports. More...

Detailed Description

An event listener which filters events on the fly before passing them on to the delegate.

Constructor & Destructor Documentation

FilteredEventListener() [1/2]

iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener.FilteredEventListener ( )

inline

Constructs a FilteredEventListener empty instance.

Constructs a FilteredEventListener empty instance. Use AttachEventListener(IEventListener, iText.Kernel.Pdf.Canvas.Parser.Filter.IEventFilter[]) to add an event listener along with its filters.

FilteredEventListener() [2/2]

iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener.FilteredEventListener ( IEventListener  delegate_, params IEventFilter[]  filterSet  )

inline

Constructs a FilteredEventListener instance with one delegate.

Constructs a FilteredEventListener instance with one delegate. Use AttachEventListener(IEventListener, iText.Kernel.Pdf.Canvas.Parser.Filter.IEventFilter[]) to add more IEventListener delegates along with their filters.

Parameters

delegate_	a delegate that will be called when all the corresponding filters for an event pass
filterSet	filters attached to the delegate that will be tested before passing an event on to the delegate

Member Function Documentation

AttachEventListener< T >()

virtual T iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener.AttachEventListener< T > ( T  delegate_, params IEventFilter[]  filterSet  )

inlinevirtual

Attaches another IEventListener delegate with its filters.

Attaches another IEventListener delegate with its filters. When all the filters attached to the delegate for an event accept the event, the event will be passed on to the delegate. You can attach multiple delegates to this FilteredEventListener instance. The content stream will be parsed just once, so it is better for performance than creating multiple FilteredEventListener instances and parsing the content stream multiple times. This is useful, for instance, when you want to extract content from multiple regions of a page.

Template Parameters

T	the type of the delegate

Parameters

delegate_	a delegate that will be called when all the corresponding filters for an event pass
filterSet	filters attached to the delegate that will be tested before passing an event on to the delegate

Returns

delegate that has been passed to the method, used for convenient call chaining

Type Constraints

T

:

IEventListener

EventOccurred()

virtual void iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener.EventOccurred ( IEventData  data, EventType  type  )

inlinevirtual

Called when some event occurs during parsing a content stream.

Parameters

data	Combines the data required for processing corresponding event type.
type	Event type.

Implements iText.Kernel.Pdf.Canvas.Parser.Listener.IEventListener.

GetSupportedEvents()

virtual ICollection<EventType> iText.Kernel.Pdf.Canvas.Parser.Listener.FilteredEventListener.GetSupportedEvents ( )

inlinevirtual

Provides the set of event types this listener supports.

Provides the set of event types this listener supports. Returns null if all possible event types are supported.

Returns

Set of event types supported by this listener or null if all possible event types are supported.

Implements iText.Kernel.Pdf.Canvas.Parser.Listener.IEventListener.