pdftron.PDF

Class ElementWriter

java.lang.Object

pdftron.PDF.ElementWriter

public class ElementWriter
extends java.lang.Object

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.

Field Summary

Fields

Modifier and Type	Field and Description
static int	e_overlay The Constant e_overlay.
static int	e_replacement The Constant e_replacement.
static int	e_underlay Enumeration describing the placement of the element written to a page.

Constructor Summary

Constructors

Constructor and Description
ElementWriter() Instantiates a new element writer.

Method Summary

Methods

Modifier and Type	Method and Description
void	begin(Doc doc) Begin writing an Element sequence to a new stream.
void	begin(Doc doc, boolean compress) Begin writing an Element sequence to a new stream.
void	begin(Obj streamobj_to_update) Begin writing an Element sequence to a stream.
void	begin(Obj streamobj_to_update, boolean compress) Begin writing an Element sequence to a stream.
void	begin(Page page) Begin writing to the given page.
void	begin(Page page, int write_mode) Begin writing to the given page.
void	begin(Page page, int write_mode, boolean page_coord_sys) Begin writing to the given page.
void	begin(Page page, int write_mode, boolean page_coord_sys, boolean compress) Begin writing to the given page.
protected void	clearList() Clear list.
void	destroy() Frees the native memory of the object.
Obj	end() Finish writing to a page.
protected void	finalize()
void	flush() The Flush method flushes all pending Element writing operations.
void	writeBuffer(byte[] data) Writes an arbitrary buffer to the content stream.
void	writeElement(Element element) Writes the Element to the content stream.
void	writePlacedElement(Element element) A utility function that surrounds the given Element with a graphics state Save/Restore Element (i.e.
void	writeString(java.lang.String str) Writes an arbitrary string to the content stream.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

e_underlay

public static final int e_underlay

Enumeration describing the placement of the element written to a page.

See Also:

Constant Field Values

e_overlay

public static final int e_overlay

The Constant e_overlay.

See Also:

Constant Field Values

e_replacement

public static final int e_replacement

The Constant e_replacement.

See Also:

Constant Field Values

Constructor Detail

ElementWriter

public ElementWriter()
              throws PDFNetException

Instantiates a new element writer.

Throws:

PDFNetException

Method Detail

destroy

public void destroy()
             throws PDFNetException

Frees the native memory of the object. This can be explicity called to control the deallocation of native memory and avoid situations where the garbage collector does not free the object in a timely manner.

Throws:

PDFNetException

begin

public void begin(Page page)
           throws PDFNetException

Begin writing to the given page. By default, new content will be appended to the page, as foreground graphics.

Parameters:

page - The page to write content.

Throws:

PDFNetException

begin

public void begin(Page page,
         int write_mode)
           throws PDFNetException

Begin writing to the given page.

Parameters:

page - The page to write content.

write_mode - the write mode

Throws:

PDFNetException

begin

public void begin(Page page,
         int write_mode,
         boolean page_coord_sys)
           throws PDFNetException

Begin writing to the given page.

Parameters:

page - The page to write content.

write_mode - the write mode

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).

Throws:

PDFNetException

begin

public void begin(Page page,
         int write_mode,
         boolean page_coord_sys,
         boolean compress)
           throws PDFNetException

Begin writing to the given page.

Parameters:

page - The page to write content.

write_mode - the write mode

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).

compress - 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.

Throws:

PDFNetException

begin

public void begin(Obj streamobj_to_update)
           throws PDFNetException

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.

Parameters:

streamobj_to_update - A low-level SDF stream object that will contain the new stream. Old stream inside that object will be discarded.

Throws:

PDFNetException

begin

public void begin(Obj streamobj_to_update,
         boolean compress)
           throws PDFNetException

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.

Parameters:

streamobj_to_update - A low-level SDF stream object that will contain the new stream. Old stream inside that object will be discarded.

compress - whether the 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 file

Throws:

PDFNetException

begin

public void begin(Doc doc)
           throws PDFNetException

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.

Parameters:

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.

Throws:

PDFNetException

Note:

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

begin

public void begin(Doc doc,
         boolean compress)
           throws PDFNetException

Begin writing an Element sequence to a new stream.

Parameters:

doc - the document that will contain the new stream.

compress - 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.

Throws:

PDFNetException

end

public Obj end()
        throws PDFNetException

Finish writing to a page.

Returns:

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

Throws:

PDFNetException

writeElement

public void writeElement(Element element)
                  throws PDFNetException

Writes the Element to the content stream.

Parameters:

element - the element to be written to the content stream

Throws:

PDFNetException

writePlacedElement

public void writePlacedElement(Element element)
                        throws PDFNetException

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.

Parameters:

element - the element

Throws:

PDFNetException

flush

public void flush()
           throws PDFNetException

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.

Throws:

PDFNetException

writeBuffer

public void writeBuffer(byte[] data)
                 throws PDFNetException

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.

Parameters:

data - the data

Throws:

PDFNetException

writeString

public void writeString(java.lang.String str)
                 throws PDFNetException

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

Parameters:

str - the str

Throws:

PDFNetException

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

clearList

protected void clearList()
                  throws PDFNetException

Clear list.

Throws:

PDFNetException