Eclipse Platform
2.0

org.eclipse.jface.text
Class AbstractLineTracker

java.lang.Object
  |
  +--org.eclipse.jface.text.AbstractLineTracker
All Implemented Interfaces:
ILineTracker
Direct Known Subclasses:
ConfigurableLineTracker, DefaultLineTracker

public abstract class AbstractLineTracker
extends Object
implements ILineTracker

Abstract implementation of ILineTracker. It lets the definition of line delimiters to subclasses. Assuming that '\n' is the only line delimiter, this abstract implementation defines the following line scheme:

This class must be subclassed.


Nested Class Summary
protected static class AbstractLineTracker.DelimiterInfo
          Combines the information of the occurence of a line delimiter.
 
Constructor Summary
protected AbstractLineTracker()
          Creates a new line tracker.
 
Method Summary
 int computeNumberOfLines(String text)
          Computes the number of lines in the given text.
 String getLineDelimiter(int line)
          Returns the line delimiter of the specified line.
 IRegion getLineInformation(int line)
          Returns a line description of the given line.
 IRegion getLineInformationOfOffset(int position)
          Returns a line description of the line at the given offset.
 int getLineLength(int line)
          Returns length of the specified line including the line's delimiter.
 int getLineNumberOfOffset(int position)
          Returns the line number the character at the given offset belongs to.
 int getLineOffset(int line)
          Returns the position of the first character of the specified line.
 int getNumberOfLines()
          Returns the number of lines.
 int getNumberOfLines(int position, int length)
          Returns the number of lines which are occupied by a given text range.
protected abstract  AbstractLineTracker.DelimiterInfo nextDelimiterInfo(String text, int offset)
          Returns the info of the first delimiter found in the given text starting at the given offset.
 void replace(int position, int length, String text)
          Informs the line tracker about the specified change in the tracked text.
 void set(String text)
          Sets the tracked text to the specified text.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.eclipse.jface.text.ILineTracker
getLegalLineDelimiters
 

Constructor Detail

AbstractLineTracker

protected AbstractLineTracker()
Creates a new line tracker.

Method Detail

getLineLength

public int getLineLength(int line)
                  throws BadLocationException
Description copied from interface: ILineTracker
Returns length of the specified line including the line's delimiter.

Specified by:
getLineLength in interface ILineTracker
Parameters:
line - the line of interest
Returns:
the length of the line
Throws:
BadLocationException - if line is unknown to this tracker

getLineNumberOfOffset

public int getLineNumberOfOffset(int position)
                          throws BadLocationException
Description copied from interface: ILineTracker
Returns the line number the character at the given offset belongs to.

Specified by:
getLineNumberOfOffset in interface ILineTracker
Parameters:
position - the offset whose line number to be determined
Returns:
the number of the line the offset is on
Throws:
BadLocationException - if the offset is invalid in this tracker

getLineInformationOfOffset

public IRegion getLineInformationOfOffset(int position)
                                   throws BadLocationException
Description copied from interface: ILineTracker
Returns a line description of the line at the given offset. The description contains the start offset and the length of the line excluding the line's delimiter.

Specified by:
getLineInformationOfOffset in interface ILineTracker
Parameters:
position - the offset whose line should be described
Returns:
a region describing the line
Throws:
BadLocationException - if offset is invalid in this tracker

getLineInformation

public IRegion getLineInformation(int line)
                           throws BadLocationException
Description copied from interface: ILineTracker
Returns a line description of the given line. The description contains the start offset and the length of the line excluding the line's delimiter.

Specified by:
getLineInformation in interface ILineTracker
Parameters:
line - the line that should be described
Returns:
a region describing the line
Throws:
BadLocationException - if line is unknown to this tracker

getLineOffset

public int getLineOffset(int line)
                  throws BadLocationException
Description copied from interface: ILineTracker
Returns the position of the first character of the specified line.

Specified by:
getLineOffset in interface ILineTracker
Parameters:
line - the line of interest
Returns:
offset of the first character of the line
Throws:
BadLocationException - if the line is unknown to this tracker

getNumberOfLines

public int getNumberOfLines()
Description copied from interface: ILineTracker
Returns the number of lines.

Specified by:
getNumberOfLines in interface ILineTracker
Returns:
the number of lines in this tracker's line structure

getNumberOfLines

public int getNumberOfLines(int position,
                            int length)
                     throws BadLocationException
Description copied from interface: ILineTracker
Returns the number of lines which are occupied by a given text range.

Specified by:
getNumberOfLines in interface ILineTracker
Parameters:
position - the offset of the specified text range
length - the length of the specified text range
Returns:
the number of lines occupied by the specified range
Throws:
BadLocationException - if specified range is unknown to this tracker

computeNumberOfLines

public int computeNumberOfLines(String text)
Description copied from interface: ILineTracker
Computes the number of lines in the given text.

Specified by:
computeNumberOfLines in interface ILineTracker
Parameters:
text - the text whose number of lines should be computed
Returns:
the number of lines in the given text

nextDelimiterInfo

protected abstract AbstractLineTracker.DelimiterInfo nextDelimiterInfo(String text,
                                                                       int offset)
Returns the info of the first delimiter found in the given text starting at the given offset.

Parameters:
text - the text to be searched
offset - the offset in the given text
Returns:
the info of the first found delimiter or null if there is no such info

replace

public void replace(int position,
                    int length,
                    String text)
             throws BadLocationException
Description copied from interface: ILineTracker
Informs the line tracker about the specified change in the tracked text.

Specified by:
replace in interface ILineTracker
Parameters:
position - the offset of the replaced text
length - the length of the replaced text
text - the substitution text
Throws:
BadLocationException - if specified range is unknown to this tracker

set

public void set(String text)
Description copied from interface: ILineTracker
Sets the tracked text to the specified text.

Specified by:
set in interface ILineTracker
Parameters:
text - the new tracked text

getLineDelimiter

public String getLineDelimiter(int line)
                        throws BadLocationException
Description copied from interface: ILineTracker
Returns the line delimiter of the specified line. Returns null if the line is not closed with a line delimiter.

Specified by:
getLineDelimiter in interface ILineTracker
Parameters:
line - the line whose line delimiter is queried
Returns:
the line's delimiter or null if line does not have a delimiter
Throws:
BadLocationException - if the line number is invalid in this tracker's line structure

Eclipse Platform
2.0

Copyright (c) IBM Corp. and others 2000, 2002. All Rights Reserved.