Package org.apache.fop.area

Class AreaTreeHandler

java.lang.Object
org.apache.fop.fo.FOEventHandler
org.apache.fop.area.AreaTreeHandler
public class AreaTreeHandler extends FOEventHandler
Area tree handler for formatting objects. Concepts: The area tree is to be as small as possible. With minimal classes and data to fully represent an area tree for formatting objects. The area tree needs to be simple to render and follow the spec closely. This area tree has the concept of page sequences. Wherever possible information is discarded or optimized to keep memory use low. The data is also organized to make it possible for renderers to minimize their output. A page can be saved if not fully resolved and once rendered a page contains only size and id reference information. The area tree pages are organized in a model that depends on the type of renderer.

  • Field Details

  • Constructor Details

    • AreaTreeHandler

      public AreaTreeHandler(FOUserAgent userAgent, String outputFormat, OutputStream stream) throws FOPException
      Constructor.
      Parameters:
      userAgent - FOUserAgent object for process
      outputFormat - the MIME type of the output format to use (ex. "application/pdf").
      stream - OutputStream
      Throws:
      FOPException - if the RenderPagesModel cannot be created

  • Method Details

    • setupModel

      protected void setupModel(FOUserAgent userAgent, String outputFormat, OutputStream stream) throws FOPException
      Sets up the AreaTreeModel instance for use by the AreaTreeHandler.
      Parameters:
      userAgent - FOUserAgent object for process
      outputFormat - the MIME type of the output format to use (ex. "application/pdf").
      stream - OutputStream
      Throws:
      FOPException - if the RenderPagesModel cannot be created

    • getAreaTreeModel

      public AreaTreeModel getAreaTreeModel()
      Get the area tree model for this area tree.
      Returns:
      AreaTreeModel the model being used for this area tree

    • getLayoutManagerMaker

      public LayoutManagerMaker getLayoutManagerMaker()
      Get the LayoutManager maker for this area tree.
      Returns:
      LayoutManagerMaker the LayoutManager maker being used for this area tree

    • getIDTracker

      public IDTracker getIDTracker()
      Get the IDTracker for this area tree.
      Returns:
      IDTracker used to track reference ids for items in this area tree

    • getResults

      public FormattingResults getResults()
      Get information about the rendered output, like number of pages created.
      Overrides:
      getResults in class FOEventHandler
      Returns:
      the results structure

    • isComplexScriptFeaturesEnabled

      public boolean isComplexScriptFeaturesEnabled()
      Check whether complex script features are enabled.
      Returns:
      true if using complex script features

    • startDocument

      public void startDocument() throws SAXException
      Prepare AreaTreeHandler for document processing This is called from FOTreeBuilder.startDocument()
      Overrides:
      startDocument in class FOEventHandler
      Throws:
      SAXException - if there is an error

    • startRoot

      public void startRoot(Root root)
      Description copied from class: FOEventHandler
      Called upon start of root element.
      Overrides:
      startRoot in class FOEventHandler
      Parameters:
      root - element

    • startPageSequence

      public void startPageSequence(PageSequence pageSequence)
      Overrides:
      startPageSequence in class FOEventHandler
      Parameters:
      pageSequence - PageSequence that is starting.

    • endPageSequence

      public void endPageSequence(PageSequence pageSequence)
      End the PageSequence. The PageSequence formats Pages and adds them to the AreaTree. The area tree then handles what happens with the pages.
      Overrides:
      endPageSequence in class FOEventHandler
      Parameters:
      pageSequence - the page sequence ending

    • startExternalDocument

      public void startExternalDocument(ExternalDocument document)
      Process the start of the external-document extension.
      Overrides:
      startExternalDocument in class FOEventHandler
      Parameters:
      document - the external-document node

    • endExternalDocument

      public void endExternalDocument(ExternalDocument document)
      Process the end of the external-document extension.
      Overrides:
      endExternalDocument in class FOEventHandler
      Parameters:
      document - the external-document node

    • notifyPageSequenceFinished

      public void notifyPageSequenceFinished(AbstractPageSequence pageSequence, int pageCount)
      Called by the PageSequenceLayoutManager when it is finished with a page-sequence.
      Parameters:
      pageSequence - the page-sequence just finished
      pageCount - The number of pages generated for the page-sequence

    • endDocument

      public void endDocument() throws SAXException
      End the document.
      Overrides:
      endDocument in class FOEventHandler
      Throws:
      SAXException - if there is some error

    • generatePageViewportKey

      public String generatePageViewportKey()
      Generates and returns a unique key for a page viewport.
      Returns:
      the generated key.

    • associateIDWithPageViewport

      @Deprecated public void associateIDWithPageViewport(String id, PageViewport pv)
      Deprecated.
      use getIDTracker().associateIDWithPageViewport(id, pv) instead
      Tie a PageViewport with an ID found on a child area of the PV. Note that an area with a given ID may be on more than one PV, hence an ID may have more than one PV associated with it.
      Parameters:
      id - the property ID of the area
      pv - a page viewport that contains the area with this ID

    • signalPendingID

      @Deprecated public void signalPendingID(String id)
      Deprecated.
      use getIDTracker().signalPendingID(id) instead
      This method tie an ID to the areaTreeHandler until this one is ready to be processed. This is used in page-number-citation-last processing so we know when an id can be resolved.
      Parameters:
      id - the id of the object being processed

    • signalIDProcessed

      @Deprecated public void signalIDProcessed(String id)
      Deprecated.
      use getIDTracker().signalIDProcessed(id) instead
      Signals that all areas for the formatting object with the given ID have been generated. This is used to determine when page-number-citation-last ref-ids can be resolved.
      Parameters:
      id - the id of the formatting object which was just finished

    • alreadyResolvedID

      @Deprecated public boolean alreadyResolvedID(String id)
      Deprecated.
      use getIDTracker().alreadyResolvedID(id) instead
      Check if an ID has already been resolved
      Parameters:
      id - the id to check
      Returns:
      true if the ID has been resolved

    • tryIDResolution

      @Deprecated public void tryIDResolution(PageViewport pv)
      Deprecated.
      use getIDTracker().tryIDResolution(pv) instead
      Tries to resolve all unresolved ID references on the given page.
      Parameters:
      pv - page viewport whose ID refs to resolve

    • getPageViewportsContainingID

      @Deprecated public List<PageViewport> getPageViewportsContainingID(String id)
      Deprecated.
      use getIDTracker().getPageViewportsContainingID(id) instead
      Get the set of page viewports that have an area with a given id.
      Parameters:
      id - the id to lookup
      Returns:
      the list of PageViewports

    • addUnresolvedIDRef

      @Deprecated public void addUnresolvedIDRef(String idref, Resolvable res)
      Deprecated.
      use getIDTracker().addUnresolvedIDRef(idref, res) instead
      Add an Resolvable object with an unresolved idref
      Parameters:
      idref - the idref whose target id has not yet been located
      res - the Resolvable object needing the idref to be resolved