Class ElementWriter

ElementWriter can be used to assemble and write new content to a page, Form XObject, Type3 Glyph stream, pattern stream, or any other content stream.

Inheritance

object

ElementWriter

Implements

IDisposable

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Namespace: pdftron.PDF

Assembly: PDFNet.dll

Syntax

public class ElementWriter : IDisposable

Constructors

ElementWriter()

Instantiates a new element writer.

Declaration

public ElementWriter()

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Methods

Begin(Page)

Begin writing to the given page.

By default, new content will be appended to the page, as foreground graphics. It is possible to add new page content as background graphics by setting the second parameter in begin method to 'true' (e.g. writer.Begin(page, true)).

Declaration

public void Begin(Page page)

Parameters

Type	Name	Description
Page	page	The page to write content.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Page, WriteMode)

Begin writing to the given page. By default, new content will be appended to the page, as foreground graphics. It is possible to add new page content as background graphics by setting the second parameter in begin method to 'true' (e.g. writer.Begin(page, true)).

Declaration

public void Begin(Page page, ElementWriter.WriteMode placement)

Parameters

Type	Name	Description
Page	page	The page to write content.
ElementWriter.WriteMode	placement	An optional flag indicating whether the new content should be added as a foreground or background layer to the existing page. By default, the new content will appear on top of the existing graphics.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Page, WriteMode, bool)

Begin writing to the given page. By default, new content will be appended to the page, as foreground graphics. It is possible to add new page content as background graphics by setting the second parameter in begin method to 'true' (e.g. writer.Begin(page, true)).

Declaration

public void Begin(Page page, ElementWriter.WriteMode placement, bool page_coord_sys)

Parameters

Type	Name	Description
Page	page	The page to write content.
ElementWriter.WriteMode	placement	An optional flag indicating whether the new content should be added as a foreground or background layer to the existing page. By default, the new content will appear on top of the existing graphics.
bool	page_coord_sys	An optional flag used to select the target coordinate system. If true (default), the coordinates are relative to the lower-left corner of the page, otherwise the coordinates are defined in PDF user coordinate system (which may, or may not coincide with the page coordinates).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Page, WriteMode, bool, bool)

Begin writing to the given page. By default, new content will be appended to the page, as foreground graphics. It is possible to add new page content as background graphics by setting the second parameter in begin method to 'true' (e.g. writer.Begin(page, true)).

Declaration

public void Begin(Page page, ElementWriter.WriteMode placement, bool page_coord_sys, bool compress)

Parameters

Type	Name	Description
Page	page	The page to write content.
ElementWriter.WriteMode	placement	An optional flag indicating whether the new content should be added as a foreground or background layer to the existing page. By default, the new content will appear on top of the existing graphics.
bool	page_coord_sys	An optional flag used to select the target coordinate system. If true (default), the coordinates are relative to the lower-left corner of the page, otherwise the coordinates are defined in PDF user coordinate system (which may, or may not coincide with the page coordinates).
bool	compress	An optional flag indicating whether the page content stream should be compressed. This may be useful for debugging content streams. Also some applications need to do a clear text search on strings in the PDF files. By default, all content streams are compressed.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Page, WriteMode, bool, bool, Obj)

Begin writing to the given page. By default, new content will be appended to the page, as foreground graphics. It is possible to add new page content as background graphics by setting the second parameter in begin method to 'true' (e.g. writer.Begin(page, true)).

Declaration

public void Begin(Page page, ElementWriter.WriteMode placement, bool page_coord_sys, bool compress, Obj resources)

Parameters

Type	Name	Description
Page	page	The page to write content.
ElementWriter.WriteMode	placement	An optional flag indicating whether the new content should be added as a foreground or background layer to the existing page. By default, the new content will appear on top of the existing graphics.
bool	page_coord_sys	An optional flag used to select the target coordinate system. If true (default), the coordinates are relative to the lower-left corner of the page, otherwise the coordinates are defined in PDF user coordinate system (which may, or may not coincide with the page coordinates).
bool	compress	An optional flag indicating whether the page content stream should be compressed. This may be useful for debugging content streams. Also some applications need to do a clear text search on strings in the PDF files. By default, all content streams are compressed.
Obj	resources	the resource dictionary in which to store resources for the final page. By default, a new resource dictionary will be created.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Obj, bool)

Begin writing an Element sequence to a stream. Use this function to write Elements to a content stream which will replace an existing content stream in an object passed as a parameter.

Declaration

public void Begin(Obj stream_obj_to_update, bool compress)

Parameters

Type	Name	Description
Obj	stream_obj_to_update	the streamobj_to_update
bool	compress	the compress

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(Obj, bool, Obj)

Begin writing an Element sequence to a stream. Use this function to write Elements to a content stream which will replace an existing content stream in an object passed as a parameter.

Declaration

public void Begin(Obj stream_obj_to_update, bool compress, Obj resources)

Parameters

Type	Name	Description
Obj	stream_obj_to_update	the streamobj_to_update
bool	compress	the compress
Obj	resources	the resource dictionary in which to store resources for the final page. By default, a new resource dictionary will be created.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(SDFDoc)

Begin writing an Element sequence to a new stream. Use this function to write Elements to a content stream other than the page. For example, you can create Form XObjects (See Section '4.9 Form XObjects' in PDF Reference for more details) pattern streams, Type3 font glyph streams, etc.

Declaration

public void Begin(SDFDoc doc)

Parameters

Type	Name	Description
SDFDoc	doc	A low-level SDF/Cos document that will contain the new stream. You can access low-level document using PDFDoc::GetSDFDoc() or Obj::GetDoc() methods.

Remarks

the newly created content stream object is returned when writing operations are completed (i.e. after the call to ElementWriter::End()).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Begin(SDFDoc, bool)

Begin writing an Element sequence to a new stream. Use this function to write Elements to a content stream other than the page. For example, you can create Form XObjects (See Section '4.9 Form XObjects' in PDF Reference for more details) pattern streams, Type3 font glyph streams, etc.

Declaration

public void Begin(SDFDoc doc, bool compress)

Parameters

Type	Name	Description
SDFDoc	doc	the doc
bool	compress	the compress

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Dispose()

Releases all resources used by the ElementWriter

Declaration

public override sealed void Dispose()

Dispose(bool)

Declaration

[HandleProcessCorruptedStateExceptions]
protected virtual void Dispose(bool A_0)

Parameters

Type	Name	Description
bool	A_0

End()

Finish writing to a page.

Declaration

public Obj End()

Returns

Type	Description
Obj	A low-level stream object that was used to store Elements.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

~ElementWriter()

Declaration

protected ~ElementWriter()

Flush()

The Flush method flushes all pending Element writing operations. This method is typically only required to be called when intermixing direct content writing (i.e. WriteBuffer/WriteString) with Element writing.

Declaration

public void Flush()

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetDefaultGState(ElementReader)

This method is used to initialize ElementWriter state with the state of a given ElementReader. This can be used to avoid incorrectly writing inherited GState attributes.

Declaration

public void SetDefaultGState(ElementReader reader)

Parameters

Type	Name	Description
ElementReader	reader	the ElementReader

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

WriteBuffer(byte[])

Writes an arbitrary buffer to the content stream. This function can be used to insert comments, inline-image data, and chunks of arbitrary content to the output stream.

Declaration

public void WriteBuffer(byte[] buf)

Parameters

Type	Name	Description
byte[]	buf	the data

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

WriteElement(Element)

Writes the Element to the content stream.

Declaration

public void WriteElement(Element element)

Parameters

Type	Name	Description
Element	element	the element

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

WriteGStateChanges(Element)

Write only the graphics state changes applied to this element and skip writing the element itself. This is especially useful when rewriting page content, but with the intention to skip certain elements.

Declaration

public void WriteGStateChanges(Element element)

Parameters

Type	Name	Description
Element	element	The element for which to write graphics state changes.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

WritePlacedElement(Element)

A utility function that surrounds the given Element with a graphics state Save/Restore Element (i.e. in PDF content stream represented as 'q element Q').

The function is equivalent to calling WriteElement three times: WriteElement(eSave); WriteElement(element); WriteElement(eRestore);

where eSave is 'e_group_begin' and eRestore is 'e_group_end' Element

The function is useful when XObjects such as Images and Forms are drawn on the page.

Declaration

public void WritePlacedElement(Element element)

Parameters

Type	Name	Description
Element	element	the element

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

WriteString(string)

Writes an arbitrary string to the content stream. Serves the same purpose as WriteBuffer().

Declaration

public void WriteString(string data)

Parameters

Type	Name	Description
string	data	the str

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Implements

IDisposable