Interface InputFeed

  • All Superinterfaces:
    StatefullComponent
    All Known Implementing Classes:
    DefaultInputFeed

    public interface InputFeed
    extends StatefullComponent
    The input feed shields the internal processing from users errors. It implements a state maschine, which checks that all documents are well formed and which does not allow users to manipulate the resulting document tree directly.

    An input feed collects all data for elements and other nodes and forwards them to the normalizer. The normalizer is the first stage of the content layouting and processing.

    Pagination ability is not propagated back to the caller. A caller will not normaly know whether a certain input caused a pagebreak. However, especially in the cases where only one page should be processed, we allow the detection of page breaks using a boolean flag. (Which is also used to detect loops.)

    The flag is reset on each call to 'startElement', 'startDocument', 'endElement', 'endDocument' and 'addText'. Attribute modifications have no effect on that flag (as these calls are accumulated into one big supercall before passing them to the normalizer.)

    Processing the meta-info also has no effect on the page-break flag, as meta- info is processed before the content is processed.

    Author:
    Thomas Morgner
    • Method Detail

      • startDocument

        void startDocument()
                    throws InputFeedException
        Starts the document processing. This is the first method to call. After calling this method, the meta-data should be fed into the inputfeed.
        Throws:
        InputFeedException
      • startMetaInfo

        void startMetaInfo()
                    throws InputFeedException
        Signals, that meta-data follows. Calling this method is only valid directly after startDocument has been called.
        Throws:
        InputFeedException
      • addDocumentAttribute

        void addDocumentAttribute​(java.lang.String name,
                                  java.lang.Object attr)
                           throws InputFeedException
        Adds document attributes. Document attributes hold object factories and document wide resources which appear only once.
        Parameters:
        name -
        attr -
        Throws:
        InputFeedException
      • startMetaNode

        void startMetaNode()
                    throws InputFeedException
        Starts a new meta-node structure. Meta-Nodes are used to hold content that can appear more than once (like stylesheet declarations).

        For now, only stylesheet declarations are defined as meta-node content; more content types will surely arise in the future.

        Calling this method is only valid after 'startMetaInfo' has been called.

        Throws:
        InputFeedException
      • setMetaNodeAttribute

        void setMetaNodeAttribute​(java.lang.String name,
                                  java.lang.Object attr)
                           throws InputFeedException
        Defines an attribute for the meta-nodes. For each meta node, at least the 'type' attribute (namespace: LibLayout) should be defined.
        Parameters:
        name -
        attr -
        Throws:
        InputFeedException
      • isPagebreakEncountered

        boolean isPagebreakEncountered()
      • resetPageBreakFlag

        void resetPageBreakFlag()
      • getCurrentNormalizer

        Normalizer getCurrentNormalizer()
        Warning; This method is needed internally, mess with it from the outside and you will run into trouble. The normalizer is a statefull component and any call to it may mess up the state. From there on, 'Abandon every hope, ye who enter here'.
        Returns: