aminePlatform.guis.prologPlusCGGUIs.prologPlusCGGUI
Class DocumentReader

java.lang.Object
  java.io.Reader
      aminePlatform.guis.prologPlusCGGUIs.prologPlusCGGUI.DocumentReader

class DocumentReader

extends java.io.Reader

A reader interface for an abstract document. Since the syntax highlighting packages only accept Stings and Readers, this must be used. Since the close() method does nothing and a seek() method has been added, this allows us to get some performance improvements through reuse. It can be used even after the lexer explicitly closes it by seeking to the place that we want to read next, and reseting the lexer.

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

DocumentReader(javax.swing.text.AbstractDocument document)
Construct a reader on the given document.

Method Summary

void	close() Has no effect.
void	mark(int readAheadLimit) Save a position for reset.
boolean	markSupported() This reader support mark and reset.
int	read() Read a single character.
int	read(char[] cbuf) Read and fill the buffer.
int	read(char[] cbuf, int off, int len) Read and fill the buffer.
boolean	ready()
void	reset() Reset this reader to the last mark, or the beginning of the document if a mark has not been set.
void	seek(long n) Seek to the given position in the document.
long	skip(long n) Skip characters of input.
void	update(int position, int adjustment) Modifying the document while the reader is working is like pulling the rug out from under the reader.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DocumentReader

public DocumentReader(javax.swing.text.AbstractDocument document)

Construct a reader on the given document.

Parameters:

document - the document to be read.

Method Detail

update

public void update(int position,
                   int adjustment)

Modifying the document while the reader is working is like pulling the rug out from under the reader. Alerting the reader with this method (in a nice thread safe way, this should not be called at the same time as a read) allows the reader to compensate.

close

public void close()

Has no effect. This reader can be used even after it has been closed.

mark

public void mark(int readAheadLimit)

Save a position for reset.

Parameters:

readAheadLimit - ignored.

markSupported

public boolean markSupported()

This reader support mark and reset.

Returns:

true

read

public int read()

Read a single character.

Returns:

the character or -1 if the end of the document has been reached.

read

public int read(char[] cbuf)

Read and fill the buffer. This method will always fill the buffer unless the end of the document is reached.

Parameters:

cbuf - the buffer to fill.

Returns:

the number of characters read or -1 if no more characters are available in the document.

read

public int read(char[] cbuf,
                int off,
                int len)

Read and fill the buffer. This method will always fill the buffer unless the end of the document is reached.

Parameters:

cbuf - the buffer to fill.

off - offset into the buffer to begin the fill.

len - maximum number of characters to put in the buffer.

Returns:

the number of characters read or -1 if no more characters are available in the document.

ready

public boolean ready()

Returns:

true

reset

public void reset()

Reset this reader to the last mark, or the beginning of the document if a mark has not been set.

skip

public long skip(long n)

Skip characters of input. This method will always skip the maximum number of characters unless the end of the file is reached.

Parameters:

n - number of characters to skip.

Returns:

the actual number of characters skipped.

seek

public void seek(long n)

Seek to the given position in the document.

Parameters:

n - the offset to which to seek.