org.apache.fop.render
Interface Renderer

All Known Implementing Classes:

AbstractRenderer

public interface Renderer

Interface implemented by all renderers. This interface is used to control the rendering of pages and to let block and inline level areas call the appropriate method to render themselves.

A Renderer implementation takes areas/spaces and produces output in some format.

Typically, most renderers are subclassed from FOP's abstract implementations (AbstractRenderer, PrintRenderer) which already handle a lot of things letting you concentrate on the details of the output format.

Field Summary

static java.lang.String

ROLE Role constant for Avalon.

Method Summary

Graphics2DAdapter	getGraphics2DAdapter()
ImageAdapter	getImageAdapter()
java.lang.String	getMimeType() Get the MIME type of the renderer.
void	preparePage(PageViewport page) This is called if the renderer supports out of order rendering.
void	processOffDocumentItem(OffDocumentItem ext) Tells the renderer to process an item not explicitly placed on the document (e.g., PDF bookmarks).
void	renderPage(PageViewport page) Tells the renderer to render a particular page.
void	setupFontInfo(FontInfo fontInfo) Set up the given FontInfo.
void	setUserAgent(FOUserAgent agent) Set the User Agent.
void	startPageSequence(LineArea seqTitle) Tells the renderer that a new page sequence starts.
void	startRenderer(java.io.OutputStream outputStream) Initiates the rendering phase.
void	stopRenderer() Signals the end of the rendering phase.
boolean	supportsOutOfOrder() Reports if out of order rendering is supported.

Field Detail

ROLE

public static final java.lang.String ROLE

Role constant for Avalon.

Method Detail

getMimeType

public java.lang.String getMimeType()

Get the MIME type of the renderer.

Returns:

The MIME type of the renderer, may return null if not applicable.

startRenderer

public void startRenderer(java.io.OutputStream outputStream)
                   throws java.io.IOException

Initiates the rendering phase. This must only be called once for a rendering. If stopRenderer is called then this may be called again for a new document rendering.

Parameters:

outputStream - The OutputStream to use for output

Throws:

java.io.IOException - If an I/O error occurs

stopRenderer

public void stopRenderer()
                  throws java.io.IOException

Signals the end of the rendering phase. The renderer should reset to an initial state and dispose of any resources for the completed rendering.

Throws:

java.io.IOException - If an I/O error occurs

setUserAgent

public void setUserAgent(FOUserAgent agent)

Set the User Agent.

Parameters:

agent - The User Agent

setupFontInfo

public void setupFontInfo(FontInfo fontInfo)

Set up the given FontInfo.

Parameters:

fontInfo - The font information

supportsOutOfOrder

public boolean supportsOutOfOrder()

Reports if out of order rendering is supported.

Normally, all pages of a document are rendered in their natural order (page 1, page 2, page 3 etc.). Some output formats (such as PDF) allow pages to be output in random order. This is helpful to reduce resource strain on the system because a page that cannot be fully resolved doesn't block subsequent pages that are already fully resolved.

Returns:

True if this renderer supports out of order rendering.

processOffDocumentItem

public void processOffDocumentItem(OffDocumentItem ext)

Tells the renderer to process an item not explicitly placed on the document (e.g., PDF bookmarks). Note - not all renderers will process all off-document items.

Parameters:

ext - The extension element to be rendered

getGraphics2DAdapter

public Graphics2DAdapter getGraphics2DAdapter()

Returns:

the adapter for painting Java2D images (or null if not supported)

getImageAdapter

public ImageAdapter getImageAdapter()

Returns:

the adapter for painting RenderedImages (or null if not supported)

preparePage

public void preparePage(PageViewport page)

This is called if the renderer supports out of order rendering. The renderer should prepare the page so that a page further on in the set of pages can be rendered. The body of the page should not be rendered. The page will be rendered at a later time by the call to renderPage(PageViewport).

Parameters:

page - The page viewport to use

startPageSequence

public void startPageSequence(LineArea seqTitle)

Tells the renderer that a new page sequence starts.

Parameters:

seqTitle - The title of the page sequence

renderPage

public void renderPage(PageViewport page)
                throws java.io.IOException,
                       FOPException

Tells the renderer to render a particular page. A renderer typically reponds by packing up the current page and writing it immediately to the output device.

Parameters:

page - The page to be rendered

Throws:

java.io.IOException - if an I/O error occurs

FOPException - if a FOP interal error occurs.