Package org.apache.xmlgraphics.ps.dsc
Class DSCParser
java.lang.Object
org.apache.xmlgraphics.ps.dsc.DSCParser
- All Implemented Interfaces:
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.
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Field Summary
Fields inherited from interface org.apache.xmlgraphics.ps.dsc.DSCParserConstants
COMMENT, DSC_COMMENT, EOF, HEADER_COMMENT, LINE
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
addListener
(DSCListener listener) Adds a DSC event listener.Returns the current event.Returns the InputStream the PostScript code is read from.getLine()
Returns the current PostScript line.boolean
hasNext()
Indicates whether there are additional items.boolean
Indicates whether the parser is configured to check for content after the EOF comment.boolean
Indicates whether the listeners are currently disabled.int
next()
Steps to the next item indicating the type of event.nextDSCComment
(String name) Advances to the next DSC comment with the given name.nextDSCComment
(String name, PSGenerator gen) Advances to the next DSC comment with the given name.Steps to the next item returning the new event.nextPSComment
(String prefix, PSGenerator gen) Advances to the next PostScript comment with the given prefix.void
parse
(DSCHandler handler) Starts the parser in push parsing mode sending events to the DSCHandler instance.protected void
Parses the next event.peek()
Returns the next event without moving the cursor to the next event.protected String
readLine()
Reads one line from the input filevoid
removeListener
(DSCListener listener) Removes a DSC event listener.void
setCheckEOF
(boolean value) Tells the parser whether to check for content after the EOF comment.void
Sets a filter for DSC events.void
setListenersDisabled
(boolean value) Allows to disable all listeners.void
Sets a NestedDocumentHandler which is used to skip nested documents like embedded EPS files.protected void
This method is used to write out warning messages for the parsing process.
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Constructor Details
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DSCParser
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 errorDSCException
- In case of a violation of the DSC spec
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Method Details
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getInputStream
Returns the InputStream the PostScript code is read from.- Returns:
- the InputStream the PostScript code is read from
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warn
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
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readLine
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 errorDSCException
- In case of a violation of the DSC spec
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parse
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 errorDSCException
- In case of a violation of the DSC spec
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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
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next
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 errorDSCException
- In case of a violation of the DSC specNoSuchElementException
- If an attempt was made to advance beyond the end of the file
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nextEvent
Steps to the next item returning the new event.- Returns:
- the new event
- Throws:
IOException
- In case of an I/O errorDSCException
- In case of a violation of the DSC spec
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getCurrentEvent
Returns the current event.- Returns:
- the current event
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peek
Returns the next event without moving the cursor to the next event.- Returns:
- the next event
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parseNext
Parses the next event.- Throws:
IOException
- In case of an I/O errorDSCException
- In case of a violation of the DSC spec
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getLine
Returns the current PostScript line.- Returns:
- the current PostScript line
- Throws:
IllegalStateException
- if the current event is not a normal PostScript line
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nextDSCComment
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 errorDSCException
- In case of a violation of the DSC spec
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nextDSCComment
Advances to the next DSC comment with the given name.- Parameters:
name
- the name of the DSC commentgen
- 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 errorDSCException
- In case of a violation of the DSC spec
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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 commentgen
- 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 errorDSCException
- In case of a violation of the DSC spec
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setFilter
Sets a filter for DSC events.- Parameters:
filter
- the filter to use or null to disable filtering
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addListener
Adds a DSC event listener.- Parameters:
listener
- the listener
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removeListener
Removes a DSC event listener.- Parameters:
listener
- the listener to remove
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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
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isListenersDisabled
public boolean isListenersDisabled()Indicates whether the listeners are currently disabled.- Returns:
- true if they are disabled
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setNestedDocumentHandler
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)
andremoveListener(DSCListener)
instead. NestedDocumentHandler is internally mapped onto aDSCListener
.- Parameters:
handler
- the NestedDocumentHandler instance or null to disable the feature
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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
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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.
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