org.jfree.layouting.layouter.feed

Interface InputFeed

All Superinterfaces:
StatefullComponent
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 Summary

void
addContent(String text)
void
addDocumentAttribute(String name, Object attr)
Adds document attributes.
void
endDocument()
void
endElement()
void
endMetaInfo()
void
endMetaNode()
Normalizer
getCurrentNormalizer()
Warning; This method is needed internally, mess with it from the outside and you will run into trouble.
NamespaceCollection
getNamespaceCollection()
void
handlePageBreakEncountered(CSSValue pageName, PseudoPage[] pseudoPages)
boolean
isPagebreakEncountered()
void
resetPageBreakFlag()
void
setAttribute(String namespace, String name, Object attr)
void
setMetaNodeAttribute(String name, Object attr)
Defines an attribute for the meta-nodes.
void
startDocument()
Starts the document processing.
void
startElement(String namespace, String name)
void
startMetaInfo()
Signals, that meta-data follows.
void
startMetaNode()
Starts a new meta-node structure.

Methods inherited from interface org.jfree.layouting.StatefullComponent

saveState

Method Details

addContent

public void addContent(String text)
            throws InputFeedException

addDocumentAttribute

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

endDocument

public void endDocument()
            throws InputFeedException

endElement

public void endElement()
            throws InputFeedException

endMetaInfo

public void endMetaInfo()
            throws InputFeedException

endMetaNode

public void endMetaNode()
            throws InputFeedException

getCurrentNormalizer

public 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:

getNamespaceCollection

public NamespaceCollection getNamespaceCollection()

handlePageBreakEncountered

public void handlePageBreakEncountered(CSSValue pageName,
                                       PseudoPage[] pseudoPages)
            throws NormalizationException

isPagebreakEncountered

public boolean isPagebreakEncountered()

resetPageBreakFlag

public void resetPageBreakFlag()

setAttribute

public void setAttribute(String namespace,
                         String name,
                         Object attr)
            throws InputFeedException

setMetaNodeAttribute

public void setMetaNodeAttribute(String name,
                                 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 -

startDocument

public 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.

startElement

public void startElement(String namespace,
                         String name)
            throws InputFeedException

startMetaInfo

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

startMetaNode

public 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.