org.apache.fop.render

Interface Renderer

Known Implementing Classes:
AbstractPathOrientedRenderer, AbstractRenderer, AFPRenderer, AWTRenderer, Java2DRenderer, PCLRenderer, PDFRenderer, PNGRenderer, PNGRenderer_onthefly, PrintRenderer, PrintRenderer, PSRenderer, SVGRenderer, TIFFRenderer, TXTRenderer, XMLRenderer

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 String
ROLE
Role constant for Avalon.

Method Summary

Graphics2DAdapter
getGraphics2DAdapter()
ImageAdapter
getImageAdapter()
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 odi)
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
setUserAgent(FOUserAgent agent)
Set the User Agent.
void
setupFontInfo(FontInfo fontInfo)
Set up the given FontInfo.
void
startPageSequence(LineArea seqTitle)
Tells the renderer that a new page sequence starts.
void
startRenderer(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 Details

ROLE

public static final String ROLE
Role constant for Avalon.

Method Details

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)

getMimeType

public String getMimeType()
Get the MIME type of the renderer.
Returns:
The MIME type of the renderer, may return null if not applicable.

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

processOffDocumentItem

public void processOffDocumentItem(OffDocumentItem odi)
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:
odi - The off-document item to be rendered

renderPage

public void renderPage(PageViewport page)
            throws 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:
FOPException - if a FOP interal 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

startPageSequence

public void startPageSequence(LineArea seqTitle)
Tells the renderer that a new page sequence starts.
Parameters:
seqTitle - The title of the page sequence

startRenderer

public void startRenderer(OutputStream outputStream)
            throws 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

stopRenderer

public void stopRenderer()
            throws 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.

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.

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