Class DSCParser

java.lang.Object
org.apache.xmlgraphics.ps.dsc.DSCParser
All Implemented Interfaces:
DSCParserConstants
public class DSCParser extends Object implements DSCParserConstants
Parser for DSC-compliant PostScript files (DSC = Document Structuring Conventions). The parser is implemented as a pull parser but has the ability to act as a push parser through the DSCHandler interface.

  • Field Details

    • LOG

      private static final org.apache.commons.logging.Log LOG

    • in

      private InputStream in

    • reader

      private BufferedReader reader

    • eofFound

      private boolean eofFound

    • checkEOF

      private boolean checkEOF

    • currentEvent

      private DSCEvent currentEvent

    • nextEvent

      private DSCEvent nextEvent

    • nestedDocumentHandler

      private DSCListener nestedDocumentHandler

    • filterListener

      private DSCListener filterListener

    • listeners

      private List listeners

    • listenersDisabled

      private boolean listenersDisabled

  • Constructor Details

    • DSCParser

      public DSCParser(InputStream in) throws IOException, DSCException
      Creates a new DSC parser.
      Parameters:
      in - InputStream to read the PostScript file from (the stream is not closed by this class, the caller is responsible for that)
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

  • Method Details

    • getInputStream

      public InputStream getInputStream()
      Returns the InputStream the PostScript code is read from.
      Returns:
      the InputStream the PostScript code is read from

    • warn

      protected void warn(String msg)
      This method is used to write out warning messages for the parsing process. Subclass to override this method. The default implementation writes to logger.
      Parameters:
      msg - the warning message

    • readLine

      protected String readLine() throws IOException, DSCException
      Reads one line from the input file
      Returns:
      the line or null if there are no more lines
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • checkLine

      private void checkLine(String line) throws DSCException
      Throws:
      DSCException

    • isWhitespace

      private boolean isWhitespace(char c)

    • parseDSCLine

      private DSCComment parseDSCLine(String line) throws IOException, DSCException
      Throws:
      IOException
      DSCException

    • parseDSCComment

      private DSCComment parseDSCComment(String name, String value)

    • parse

      public void parse(DSCHandler handler) throws IOException, DSCException
      Starts the parser in push parsing mode sending events to the DSCHandler instance.
      Parameters:
      handler - the DSCHandler instance to send the events to
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • hasNext

      public boolean hasNext()
      Indicates whether there are additional items.
      Returns:
      true if there are additonal items, false if the end of the file has been reached

    • next

      public int next() throws IOException, DSCException
      Steps to the next item indicating the type of event.
      Returns:
      the type of event (See DSCParserConstants)
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec
      NoSuchElementException - If an attempt was made to advance beyond the end of the file

    • processListeners

      private void processListeners() throws IOException, DSCException
      Throws:
      IOException
      DSCException

    • nextEvent

      public DSCEvent nextEvent() throws IOException, DSCException
      Steps to the next item returning the new event.
      Returns:
      the new event
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • getCurrentEvent

      public DSCEvent getCurrentEvent()
      Returns the current event.
      Returns:
      the current event

    • peek

      public DSCEvent peek()
      Returns the next event without moving the cursor to the next event.
      Returns:
      the next event

    • parseNext

      protected void parseNext() throws IOException, DSCException
      Parses the next event.
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • getLine

      public String getLine()
      Returns the current PostScript line.
      Returns:
      the current PostScript line
      Throws:
      IllegalStateException - if the current event is not a normal PostScript line

    • nextDSCComment

      public DSCComment nextDSCComment(String name) throws IOException, DSCException
      Advances to the next DSC comment with the given name.
      Parameters:
      name - the name of the DSC comment
      Returns:
      the requested DSC comment or null if the end of the file is reached
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • nextDSCComment

      public DSCComment nextDSCComment(String name, PSGenerator gen) throws IOException, DSCException
      Advances to the next DSC comment with the given name.
      Parameters:
      name - the name of the DSC comment
      gen - PSGenerator to pass the skipped events though to
      Returns:
      the requested DSC comment or null if the end of the file is reached
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • nextPSComment

      public PostScriptComment nextPSComment(String prefix, PSGenerator gen) throws IOException, DSCException
      Advances to the next PostScript comment with the given prefix. This is used to find comments following the DSC extension mechanism.

      Example: To find FOP's custom comments, pass in "FOP" as a prefix. This will find comments like "%FOPFontSetup".

      Parameters:
      prefix - the prefix of the extension comment
      gen - PSGenerator to pass the skipped events though to
      Returns:
      the requested PostScript comment or null if the end of the file is reached
      Throws:
      IOException - In case of an I/O error
      DSCException - In case of a violation of the DSC spec

    • setFilter

      public void setFilter(DSCFilter filter)
      Sets a filter for DSC events.
      Parameters:
      filter - the filter to use or null to disable filtering

    • addListener

      public void addListener(DSCListener listener)
      Adds a DSC event listener.
      Parameters:
      listener - the listener

    • removeListener

      public void removeListener(DSCListener listener)
      Removes a DSC event listener.
      Parameters:
      listener - the listener to remove

    • setListenersDisabled

      public void setListenersDisabled(boolean value)
      Allows to disable all listeners. This can be used to disable any filtering, for example in nested documents.
      Parameters:
      value - true to disable all listeners, false to re-enable them

    • isListenersDisabled

      public boolean isListenersDisabled()
      Indicates whether the listeners are currently disabled.
      Returns:
      true if they are disabled

    • setNestedDocumentHandler

      public void setNestedDocumentHandler(NestedDocumentHandler handler)
      Sets a NestedDocumentHandler which is used to skip nested documents like embedded EPS files. You can also process those parts in a special way.

      It is suggested to use the more generally usable addListener(DSCListener) and removeListener(DSCListener) instead. NestedDocumentHandler is internally mapped onto a DSCListener.

      Parameters:
      handler - the NestedDocumentHandler instance or null to disable the feature

    • setCheckEOF

      public void setCheckEOF(boolean value)
      Tells the parser whether to check for content after the EOF comment. This can be disabled to skip nested documents.
      Parameters:
      value - true if the check is enabled

    • isCheckEOF

      public boolean isCheckEOF()
      Indicates whether the parser is configured to check for content after the EOF comment.
      Returns:
      true if the check is enabled.