de.hunsicker.jalopy.swing.syntax
Class TokenMarker

java.lang.Object
  |
  +--de.hunsicker.jalopy.swing.syntax.TokenMarker
Direct Known Subclasses:
JavaTokenMarker

public abstract class TokenMarker
extends java.lang.Object

A token marker that splits lines of text into tokens. Each token carries a length field and an indentification tag that can be mapped to a color for painting that token.

For performance reasons, the linked list of tokens is reused after each line is tokenized. Therefore, the return value of markTokens should only be used for immediate painting. Notably, it cannot be cached.

Version:
$Id: TokenMarker.java,v 1.1 2002/11/11 22:08:35 marcohu Exp $
Author:
Slava Pestov
See Also:
org.gjt.sp.jedit.syntax.Token

Nested Class Summary
static class TokenMarker.LineInfo
          Inner class for storing information about tokenized lines.
 
Field Summary
protected  Token firstToken
          The first token in the list.
protected  Token lastToken
          The last token in the list.
protected  int length
          The length of the lineInfo array.
protected  TokenMarker.LineInfo[] lineInfo
          An array for storing information about lines.
protected  boolean nextLineRequested
          True if the next line should be painted.
 
Constructor Summary
protected TokenMarker()
          Creates a new TokenMarker.
 
Method Summary
protected  void addToken(int length, byte id)
          Adds a token to the token list.
 void deleteLines(int index, int lines)
          Informs the token marker that line have been deleted from the document.
protected  void ensureCapacity(int index)
          Ensures that the lineInfo array can contain the specified index.
 void insertLines(int index, int lines)
          Informs the token marker that lines have been inserted into the document.
 boolean isNextLineRequested()
          Returns true if the next line should be repainted.
 Token markTokens(javax.swing.text.Segment line, int lineIndex)
          A wrapper for the lower-level markTokensImpl method that is called to split a line up into tokens.
protected abstract  byte markTokensImpl(byte token, javax.swing.text.Segment line, int lineIndex)
          An abstract method that splits a line up into tokens.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

firstToken

protected Token firstToken
The first token in the list. This should be used as the return value from markTokens().


lastToken

protected Token lastToken
The last token in the list. New tokens are added here. This should be set to null before a new line is to be tokenized.


lineInfo

protected TokenMarker.LineInfo[] lineInfo
An array for storing information about lines. It is enlarged and shrunk automatically by the insertLines() and deleteLines() methods.


nextLineRequested

protected boolean nextLineRequested
True if the next line should be painted.


length

protected int length
The length of the lineInfo array.

Constructor Detail

TokenMarker

protected TokenMarker()
Creates a new TokenMarker. This DOES NOT create a lineInfo array; an initial call to insertLines() does that.

Method Detail

isNextLineRequested

public boolean isNextLineRequested()
Returns true if the next line should be repainted. This will return true after a line has been tokenized that starts a multiline token that continues onto the next line.

Returns:
DOCUMENT ME!

deleteLines

public void deleteLines(int index,
                        int lines)
Informs the token marker that line have been deleted from the document. This removes the lines in question from the lineInfo array.

Parameters:
index - The first line number
lines - The number of lines

insertLines

public void insertLines(int index,
                        int lines)
Informs the token marker that lines have been inserted into the document. This inserts a gap in the lineInfo array.

Parameters:
index - The first line number
lines - The number of lines

markTokens

public Token markTokens(javax.swing.text.Segment line,
                        int lineIndex)
A wrapper for the lower-level markTokensImpl method that is called to split a line up into tokens.

Parameters:
line - The line
lineIndex - The line number
Returns:
DOCUMENT ME!

markTokensImpl

protected abstract byte markTokensImpl(byte token,
                                       javax.swing.text.Segment line,
                                       int lineIndex)
An abstract method that splits a line up into tokens. It should parse the line, and call addToken() to add syntax tokens to the token list. Then, it should return the initial token type for the next line.

For example if the current line contains the start of a multiline comment that doesn't end on that line, this method should return the comment token type so that it continues on the next line.

Parameters:
token - The initial token type for this line
line - The line to be tokenized
lineIndex - The index of the line in the document, starting at 0
Returns:
The initial token type for the next line

addToken

protected void addToken(int length,
                        byte id)
Adds a token to the token list.

Parameters:
length - The length of the token
id - The id of the token
Throws:
java.lang.InternalError - DOCUMENT ME!

ensureCapacity

protected void ensureCapacity(int index)
Ensures that the lineInfo array can contain the specified index. This enlarges it if necessary. No action is taken if the array is large enough already.

It should be unnecessary to call this under normal circumstances; insertLine() should take care of enlarging the line info array automatically.

Parameters:
index - The array index


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